2,119 results on '"BORED piles"'
Search Results
2. Innovative Fundamentierungen mit Fertigschraubpfählen.
- Author
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Boley, Conrad, Höppner, Robert, Pratter, Paul, and Thurner, Günther
- Subjects
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BUILDING sites , *BUILDING foundations , *GEOTECHNICAL engineering , *TEMPORARY employment , *STEEL , *BORED piles , *SCREWS - Abstract
Innovative foundations with screw piles Screw piles are getting more important in geotechnical engineering. This report presents current innovations in the use and design of screw piles. The specifics of the foundation system are explained, the load test with reduced testing time is presented and further application possibilities, such as the inclined installation of the screw piles for the transfer of horizontal loads, are presented. In contrast to conventional foundation elements made of steel and concrete, screw piles consist exclusively of a prefabricated steel load‐bearing element, are screwed into the ground and can be loaded immediately. There is no need for concreting, which not only significantly reduces the construction site set‐up and construction time, but also enables the screw piles to be removed after temporary construction work. This not only minimizes the impact on the environment during the project, it is also innovative in terms of sustainability as the foundation system can be fully reused for new projects. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Experimental study on partially tapered belled piles subjected to inclined load in sand.
- Author
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Goudar, Shivarajkumar. and Kamatagi, Allamaprabhu.
- Subjects
BORED piles ,SPECIFIC gravity ,COMPRESSION loads ,SAND ,ALUMINUM - Abstract
In the present investigation, several experiments are carried out on statically inclined compressive loads on model aluminium partially tapered belled piles (PTBP) and bored piles (BP). The partially tapered bell is formed by providing outer extension angle alpha (α) as 3°, 5° and 7° at the middle of every model pile. These tests are carried out on 1 × 1and 1 × 2 pile groups having L/D of 12, 17, and 22. The model piles tested in the relative density of medium dense (R
d = 39.5%) and dense sand (Rd = 70%) with spacing to diameter ratio (S/D) of 3, 4, and 5 to both BP and PTBP. The comparisons between PTBP and BP test results are expressed in the form of load-deflection curves. The effect of pile geometry, outer extension angle, pile spacing, and influence of relative density are carefully investigated. From the investigation, it is found that the optimum value of the L/D ratio is 22, α is 7° and the S/D ratio is 5Db , (Db is PTBP base diameter) this configuration achieved 41.46% greater load carrying capacity in the dense state of sand bed as compared with the medium dense state of sand bed with the same configuration. [ABSTRACT FROM AUTHOR]- Published
- 2024
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4. A novel method for construction of railway stations based on continuous open caissons.
- Author
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Liu, Shu, Zhang, Zhongjie, Yuan, Yong, Taerwe, Luc, and Zhang, Jiao‐Long
- Subjects
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INDUSTRIALIZED building , *STRUCTURAL engineering , *BORED piles , *CIVIL engineering , *REINFORCED concrete , *CAISSONS , *SPACE frame structures - Abstract
The article discusses a novel method for constructing railway stations using continuous open caissons, focusing on the Cao-Zhuang Station in China. This method involves sinking closely spaced open caissons and longitudinally penetrating them to create a unique underground structural design. The construction of the station is projected to be completed by January 2025 and offers advantages such as reducing construction time, saving investment costs, and promoting environmental protection. The study provides detailed insights into the structural design and construction process of the station, emphasizing the importance of longitudinal settlement control and structural integrity. [Extracted from the article]
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- 2024
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5. Bearing capacity of constrained grouting expansion bored pile based on CPTU and expansion tests.
- Author
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Tang, Daofei, Changhong, Wang, Ma, Chengtao, Wang, Kun, Li, Tianhu, and Shen, Yang
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BORED piles , *SOIL consolidation , *GROUTING , *COMPUTER simulation , *FRICTION - Abstract
AbstractBored Pile of Constrained Grouting Expansion (BPCGE) is a new type of pile that combines grouting, compression, and expansion technologies. However, there is still insufficient understanding of its bearing characteristics and strength degradation, especially when the surrounding mass is located in soft cohesive soil layers. To address the issues mentioned above, analysis of bearing capacity and strength assessment of BPCGE based on piezocone penetration test (CPTU) and expansion tests are taken into account. Firstly, based on the similarity between the pile prototypes and models, constrained grouting expansion tests are conducted to study the borehole expansion and soil consolidation effects, and analyze the influence on effective stress of soil around the pile and stress relaxation characteristics of cohesive soil. Secondly, CPTU tests and numerical simulations were carried out to investigate the size effect of BPCGE, and a conversion relationship between lateral friction resistance of pile and CPTU friction resistance was established. Finally, the ultimate bearing capacity of BPCGE is proposed. In an application of a high-rise residential project, the calculation method based on CPTU data can effectively predict the ultimate bearing capacity of BPCGE, saving 262 ordinary piles. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Research on Spatiotemporal Evolution Methods Networks Based on Deep Learning: Arctic Shipping Data as a Case.
- Author
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Li, Changrong, Wei, Duan, and Li, Zhenfu
- Subjects
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GENERATIVE adversarial networks , *BORED piles , *DEEP learning , *VEHICULAR ad hoc networks - Abstract
ABSTRACT This article uses deep learning to study the spatiotemporal evolution method of vehicular ad‐hoc networks (VANETs). Firstly, the research background and significance are introduced, as well as the research status of VANET spatiotemporal evolution methods and deep learning‐based VANET spatiotemporal evolution methods both domestically and internationally. Then, the related theoretical foundations of deep learning and traditional VANET spatiotemporal evolution methods are elaborated in detail. Subsequently, three VANET spatiotemporal evolution methods based on long short‐term memory‐convolutional neural network (LSTM‐CNN), deep time generative adversarial network (D‐TGAN), and fully connected network (FCN) are proposed, and simulation experiments are conducted for each method to analyze the experimental results. Finally, the main work of the whole article is summarized, and future research directions are discussed. Through this study, new ideas and methods can be provided for the development of VANET spatiotemporal evolution methods. [ABSTRACT FROM AUTHOR]
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- 2024
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7. 滨海地区砂质粉土地层深大基坑工程设计与施工.
- Author
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古徐莉, 孙海忠, and 黄天荣
- Subjects
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BUILDING foundations , *BORED piles , *REINFORCED concrete , *WATER levels , *REQUIREMENTS engineering - Abstract
The geotechnical characteristics have a significant impact on the design and construction of deep and largefoundation pit engineering. In response to technical difficulties such as strong permeability of sandy silt, takingadeep and largefoundation pit project in Lingang New City of Shanghai as an example, a detailed comparison and selection of foundation pitenclosure design schemes was carried out in comprehensive consideration of hydrogeology and other factors, andascheme ofSMW construction method piles with reinforced concrete support in the north -south, and east-west directions was proposed,and the measures were adopted including using construction piles to penetrate through silty clay to isolate external hydraulicconnections, pre dewatering the foundation pit to 1 m below the bottom, and strengthening monitoring of water level and deepdisplacement. And then the construction scheme was calculated and reviewed using structural calculation software. Engineeringapplications have shown that the construction process of foundation pits is safe and controllable, and the displacement ofretaining piles and ground settlement meet the requirement of relevant specifications. This support structure scheme isreasonable and effective. The relevant conclusions can provide theoretical guidance and technical support for the design andconstruction of similar deep and large foundation pit projects. [ABSTRACT FROM AUTHOR]
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- 2024
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8. 龙口南山 LNG 接收站取排水工程沉井施工技术.
- Author
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王建 and 张浩男
- Subjects
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BUILDING foundations , *BORED piles , *UNDERGROUND construction , *REINFORCED concrete , *WATER pumps - Abstract
Caisson is a construction technique for building deep foundations and underground buildings, which has been widely used in deep pit, equipment foundation, water pump house, water intake and other projects. The foundation of these a water pump house of the Longkou Nanshan LNG Receiving Station Phase I project adopts reinforced concrete caisson structure. The caisson of the project is on a soft soil layer foundation, which is prone to risks such as deviation, quicksand, pipe surge and sudden sinking. To effectively avoid the above risks, through the technical research on the sinking coefficient and stability of the caisson in each stage, the construction methods and risk countermeasures applicable to the caisson of the project were formulated to ensure high -quality and efficient construction of the caisson of the project, which can provide relevant reference for other similar projects. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. SeFi-CD: A Semantic First Change Detection Paradigm That Can Detect Any Change You Want.
- Author
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Zhao, Ling, Huang, Zhenyang, Wang, Yipeng, Peng, Chengli, Gan, Jun, Li, Haifeng, and Hu, Chao
- Subjects
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LANGUAGE models , *BORED piles , *DEEP learning - Abstract
The existing change detection (CD) methods can be summarized as the visual-first change detection (ViFi-CD) paradigm, which first extracts change features from visual differences and then assigns them specific semantic information. However, CD is essentially dependent on change regions of interest (CRoIs), meaning that the CD results are directly determined by the semantics changes in interest, making its primary image factor semantic of interest rather than visual. The ViFi-CD paradigm can only assign specific semantics of interest to specific change features extracted from visual differences, leading to the inevitable omission of potential CRoIs and the inability to adapt to different CRoI CD tasks. In other words, changes in other CRoIs cannot be detected by the ViFi-CD method without retraining the model or significantly modifying the method. This paper introduces a new CD paradigm, the semantic-first CD (SeFi-CD) paradigm. The core idea of SeFi-CD is to first perceive the dynamic semantics of interest and then visually search for change features related to the semantics. Based on the SeFi-CD paradigm, we designed Anything You Want Change Detection (AUWCD). Experiments on public datasets demonstrate that the AUWCD outperforms the current state-of-the-art CD methods, achieving an average F1 score 5.01% higher than that of these advanced supervised baselines on the SECOND dataset, with a maximum increase of 13.17%. The proposed SeFi-CD offers a novel CD perspective and approach. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. Optimisation for sandy pebble deep foundation pit support based on multi-objective fuzzy grey relation projection method.
- Author
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Cheng, Xuansheng, Yin, Siyuan, Li, Xinlei, Su, Hongling, and Chen, Chaobo
- Subjects
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BUILDING foundations , *BORED piles , *REFERENCE values , *PEBBLES , *EVALUATION methodology - Abstract
Many influencing factors should be considered in the selection of deep foundation pit supporting scheme. And the impact of different factors on supporting scheme is difficult to measure. There is a grey correlation between many influencing factors and the selection of supporting schemes. In this paper, the multi-objective fuzzy grey relation projection method can be obtained by weighting method and used to select the support of foundation pit. Therefore, a set of corresponding evaluation indexes of deep foundation pit support is put forward and the weight of each evaluation index is given. Then the weight is brought into the multi-objective fuzzy grey relation projection method to select the supporting mode of foundation pit. This method is applied to the selection of the supporting mode of the foundation pit of sand-pebble station, and the optimal supporting mode is obtained. The results is as follows : (1) It is effective to select the supporting scheme of foundation pit by fuzzy grey relational projection method. (2) The evaluation index of deep foundation pit supporting is reasonable. (3) It is of certain reference value to adopt bored pile + steel support method for sandy pebble foundation pit. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. PROCESSO EXECUTIVO DE FUNDAÇÕES COM ESTACA BROCA - ESTUDO DE CASO: CONSTRUÇÃO DO MURO DO INSTITUTO NACIONAL DE PESQUISA DA AMAZÔNIA (INPA).
- Author
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Bezerra Teixeira, Juliana, Nogueira Marques Pinheiro, Érika Cristina, and da Fonseca Santos, Karoline Socorro
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BUILDING foundations ,BORED piles ,REGULATORY compliance ,AUGERS ,RESEARCH institutes - Abstract
Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
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12. Parameter Identification of a Soil Constitutive Model Based on a Hybrid Genetic Differential Evolution Algorithm.
- Author
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Long, Lin, Li, Yunyu, Yang, Peiling, and Tang, Bo
- Subjects
OPTIMIZATION algorithms ,BUILDING foundations ,SOIL creep ,BORED piles ,GENETIC algorithms ,DIFFERENTIAL evolution - Abstract
Aiming to address the problem of selecting the parameters of a soil constitutive model in the calculation of foundation pit stability, this paper proposes a hybrid genetic differential evolution algorithm (GADE) which performs by "jumping out of local optima" with "fast convergence" based on the hybrid optimization algorithm strategy and compares the advantages and disadvantages of genetic algorithms (GAs) and differential evolution algorithms (DEs). Three typical test functions were used to evaluate the search efficiency and convergence speed of GAs, DEs, and GADE, respectively. It was found that GADE has the fastest convergence speed and can search for the global optimal solution to the problem, which highlights its excellent optimization performance. At the same time, taking the Shimao Binjiang deep foundation pit as an example, GADE was used to invert the soil modulus parameters of a CX1 measuring point and construct a finite-element model for calculation. The results showed that the simulated calculation curve and the measured displacement curve were in good agreement and the curve fitting reached 95.05%, indicating the applicability and feasibility of applying GADE to identify soil parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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13. Research on Mechanical Characteristics of High-Toughness Anti-Slip Pile Based on Slope Anti-Slip Stability Enhancement.
- Author
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Xing, Changzhu, Yang, Yanwei, Zheng, Chuanfeng, Liu, Dayu, Li, Haigang, Guo, Liying, Lin, Weitao, and Wang, Chengda
- Subjects
BUILDING foundations ,DEEP foundations (Engineering) ,RURAL water supply ,SLOPE stability ,BORED piles - Abstract
Aiming at the problem of insufficient slope stability in deep foundation pit engineering, this paper takes the integrated urban and rural water supply project in Lingao County as the research object, simulates and analyzes the landslide process of the slope by using the strength discount method, and explores the mechanical response characteristics of the anti-slip piles in depth. It is found that the traditional anti-slip pile is prone to early failure due to bending and tensile damage in the middle of the pile back, which leads to the decline of slope stability. For this reason, this paper designs and studies the high-toughness anti-slip pile material and carries out numerical simulation analyses on C30 concrete anti-slip piles and high-toughness concrete anti-slip piles, respectively, for 9 working conditions, for a total of 18 working conditions. The results show that the bending and tensile toughness and strength of the anti-slip piles are significantly improved by using high-toughness material, which effectively avoids bending and tensile damage, and the slope safety coefficient is increased by 32.10%. Furthermore, the optimized design of anti-slip piles in terms of material, pile length, and pile position can effectively improve the stability of slopes and prolong the service life of the anti-slip piles, which provides a new way of thinking and methodology for the safety design of the deep foundation pit project. Thus, this study has important theoretical significance and engineering application value. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. Database Analysis of Long-Term Settlement Behavior of Pile Foundations in Shanghai Soft Coastal Clays.
- Author
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Wang, Qibiao, Li, Jie, Fang, Tao, and Yu, Shaohua
- Subjects
BUILDING foundations ,BORED piles ,SETTLEMENT of structures ,DATABASES ,PREDICTION models - Abstract
A database of 195 field records of long-term settlement of high-rise buildings in Shanghai soft coastal clays is presented. The collected field records are divided into two categories based on pile type, i.e., bored pile and precast pile. Based on the settlement recorders collected, the long-term settlement behavior and settlement duration of the pile foundations in soft coastal clays are investigated. The statistical results show that the pile foundation in Shanghai soft coastal clays can be divided into three kinds of site conditions by considering the pile length and variation of long-term deformation behavior. Prediction models based on the power function are proposed to calculate the normalized final settlement for both bored pile and precast pile foundations. Based on the statistical results, the average normalized final settlement (settlement per floor), average settlement ratio (final settlement to the settlement when the superstructure is completed), and average settlement duration in the three site conditions for both bored pile and precast pile foundations are given. Additionally, an exponential settlement prediction model that can accurately forecast the entire settlement and post-construction settlement characteristics of buildings in Shanghai's soft soil area is proposed. These statistical results can be referred to the preliminary foundation design works, which contribute to the quick evaluation of the possible settlement range, settlement ratio, and settlement duration of the proposed building constructed in the soft coastal clay area in Shanghai. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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15. The Amfioen Societëit (1745–1794): Opium, intra-Asian trade and the commercial world of Batavia in the eighteenth century.
- Author
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Richardson, Noelle Nadiah
- Subjects
COLONIAL administration ,SUGAR industry ,BORED piles ,EIGHTEENTH century ,OPIUM - Abstract
This article analyses the emergence of the Amfioen Societëit (1745–1794) and its impact on the market for opium in eighteenth-century Java. It engages with a limited body of historiography to challenge assumptions that the Societëit was a wholly colonial institution designed to serve an elite – namely, European – set of interests. In reassessing how the Societëit worked in theory and in practice, it is argued that this institution was born from the necessary collaborative engagement of a European and a local commercial class with different but vested interests in the opium trade. Moreover, the article situates the Societëit among other finance institutions that existed in eighteenth-century Java to serve the credit needs of the local commercial milieu. In doing so, it lays the foundations for a deeper and more nuanced history of the opium trade and the local economy of early modern Java in a period about which very little is known. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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16. Laboratory Investigation of Deep Soil Mixing for the Improvement of Salt-Cemented Soils.
- Author
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Hammad, Mohammed A., Mohamedzein, Yahia E.-A., Al-Aghbari, Mohammed Y., and Al-Nuaimi, Ali S.
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BEARING capacity of soils ,SOIL salinity ,BUILDING foundations ,BORED piles ,SCANNING electron microscopes - Abstract
Salt-cemented soils are problematic soils and known for high compressibility and inadequate shear strength, pose significant challenges to structural stability. This paper investigates stabilizing such soils using deep soil mixing (DSM) technique, a cost-effective alternative to traditional deep foundations. A series of laboratory-scale models were employed to evaluate the performance of stabilized salt-cemented soils under various soil states. A specially designed deep soil mixing apparatus was employed to prepare a DSM column within a steel tank, with instrumentation for measuring induced stresses and settlements under various soil conditions. The results demonstrated that DSM significantly enhances bearing capacity and reduces settlement, with effectiveness influenced by factors such as salt content and total water content (TWC). The TWC, which includes initial water content and water/binder ratio, is critical for mixing efficiency and should be critically designed prior to the treatment to achieve the maximum possible improvement. TWC is equal to 41% contributing to the highest column strength and hence the ultimate bearing capacity. Scanning electron microscope images revealed denser structures in treated columns, indicating improved soil contact and strength. While the ultimate bearing capacity decreases with higher salt content, improvements ranged from 125 to 150% depending on salt concentration. Chemical interactions between soil salts and cementitious materials were also found to enhance shear strength over time. The study's findings provide valuable guidelines for optimizing DSM treatment parameters to effectively stabilize salt-cemented soils. The developed models were validated against past design equations and real-world tests, confirming their reliability and effectiveness. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Sensitivity Assessment and 3D Finite Element Analysis of the Behavior of Bored Capped Pile in Sandy Soils Under Axial Tensile and Lateral Loading.
- Author
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Shalabi, Faisal I., Saleem, Mohammad U., and Tamimi, Mohammad F.
- Subjects
FINITE element method ,BUILDING foundations ,SANDY soils ,BORED piles ,YOUNG'S modulus ,LATERAL loads - Abstract
This study employs variance-based and parametric analyses to quantify the impact of geometric and mechanical properties on the performance of pile foundations under axial tensile (P
a ) and lateral (PL ) loading. Utilizing 3D finite element analysis with the Drucker-Prager model, the research investigates pile-pile cap interaction across varying soil moduli (Es = 5, 20, & 50 MPa) and length-to-diameter (L/D) ratios (10, 20, & 33). The sensitivity analysis identifies the friction coefficient between sand and pile, as well as pile diameter, as the most influential factors, followed by pile length and the Young's modulus of both the pile and the sand. Parametric analysis reveals that pile deformation, contact pressure (Pc ), and shear stresses (fs ) are strongly affected by Es and the L/D ratio. Under Pa loading, as Es and L/D decrease, fs increases up to a certain depth before decreasing. Additionally, the normalized Pa to axial deformation ratio (Pa /δa ) decreases with increasing relative stiffness of the pile to soil (Ep /Es ), with L/D becoming increasingly influential as Ep /Es decreases. Under PL loading, increased L/D and Es result in greater pile flexibility and a concentration of Pc at the top. The pile's lateral deformation behavior with depth mirrors the Pc distribution. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
18. Bearing Capacity Evaluation of Deep Foundations in Liquefiable Soils Using Piezocone Test Data.
- Author
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Maleki, Mohammad, Eslami, Abolfazl, Nabizadeh, Ali, and Bahmanpour, Amin
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BUILDING foundations ,BORED piles ,CONE penetration tests ,SOIL liquefaction ,DYNAMIC loads ,BEARING capacity of soils ,PORE water pressure - Abstract
The utilization of cone penetration test (CPT & CPTu) results to assess the bearing capacity of deep foundations stands as a crucial application in geotechnical engineering. This study focuses on leveraging the outputs of the CPT test, considering the distinctive features of piles and the abundance of reliable information, coupled with the rapidity of the test. The CPT test outcomes can be employed both directly and indirectly to ascertain the capacity of the toe and shaft resistance of piles. In seismic conditions, applying earthquake acceleration to sensitive and liquefiable soils induces an increase in pore water pressure Δu, leading to a subsequent reduction in soil strength. Thus, investigating changes in excessive pore water pressure serves as a key dynamic load indicator in seismic scenarios. This research initially determines the bearing capacity of deep foundations through common methods using CPT data. Subsequently, key parameters influencing the development and dissipation of Δu, such as soil sensitivity (St), undrained shear strength (Su), and dimensionless parameters of pore water pressure 1 - B q and 1 - u 2 q t , are meticulously evaluated. This study proceeds to investigate the impact of these parameters on the bearing capacity of deep foundations, drawing insights from a comprehensive database encompassing CPT & CPTu data from 18 diverse sites worldwide. Comparative analysis between the proposed method and conventional approaches reveals a significant reduction in the aforementioned parameters' influence on the bearing capacity of deep foundations. Consequently, this finding underscores the necessity of incorporating such considerations in geotechnical bearing capacity calculations for projects situated on soils prone to liquefaction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Practical Recommendations for Defect Avoidance in Deep Foundations.
- Author
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Wilkes, Christopher, Kanavaris, Fragkoulis, Barker, Chris, and Nicholson, Duncan
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BUILDING foundations ,BORED piles ,CONCRETE testing ,RHEOLOGY ,DESIGN - Abstract
This paper presents a method for simply qualifying the practical risk of casting deep foundations based upon a combination of the behavior of the fresh concrete through testing and the confinement conditions of the foundation from a design perspective. A framework to qualify which aspects of the tremie process lead to defects is developed for the first time. Flow behavior, confinement conditions, and free-water availability are identified as key contributors to specific defects present within tremie concrete foundations. Finally, a novel risk map for tremie concrete is presented. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. Calculation model for settlement of soft soil foundation with continuous drainage boundary considering the Hansbo's flow law and the linear load.
- Author
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Xu, Yunbo, Zhang, Jiachao, Liu, Zhongyu, and Cui, Penglu
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BUILDING foundations ,BORED piles ,SOIL consolidation ,SOFT law ,DRAINAGE - Abstract
To ensure the safety of deep foundation pit construction, this paper proposes a settlement calculation model for deep foundation pits in soft soil areas. In this model, factors such as the non-Darcian flow law of soft soil, the varying boundary drainage capacity, and the construction loads are considered. Among them, the Hansbo's flow and the linear load are used to portray the complicated conditions in real-world engineering, and the continuous drainage boundary is utilized to describe changes in drainage performance of soil boundaries. Comparing the effectiveness of the suggested solution to prior research has confirmed its efficacy. Then, using a number of examples, the consolidation mechanism of soil with continuous drainage boundary is examined in light of Hansbo's flow law and the linear load. The pore pressure in soil layers with continuous drainage boundaries under linear load exhibits a trend of initially increasing and then dropping, according to numerical research. Furthermore, the peak of the increase in pore pressure is substantially impacted by Hansbo's flow equation. The bigger the parameters in the Hansbo's flow law, the longer the linear loading time, and the slower the settlement in the soil layer with the continuous drainage boundary are additional factors. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Barrier Effect of Existing Building Pile on the Responses of Groundwater and Soil During Foundation Pit Dewatering.
- Author
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He, Dongyang, Zeng, Chaofeng, Xu, Changjie, Xue, Xiuli, Zhao, Youwu, Han, Lei, and Sun, Haiyu
- Subjects
BUILDING foundations ,BORED piles ,CURTAIN walls ,GROUNDWATER ,COMPUTER simulation - Abstract
In regions with abundant groundwater resources, pre-excavation dewatering on deep foundation pits often leads to the deformation of the enclosure wall and settlement of the surrounding ground. Based on a series of engineering measurements, we conducted a series of numerical simulations to investigate the behaviors of wall and soil during pre-excavation dewatering with and without the existing pile foundations and under different distances between the existing pile foundations and foundation pits (D). Numerical results indicated that when the foundation pit is adjacent to existing building pile foundations, the soil was restricted by the pile foundations (i.e., soil-blocking effect). When D ≤ 40 m, the soil-blocking effect grows stronger as D gets smaller; while when D > 40 m, the soil-blocking effect is significantly weakened and the water-blocking effect (i.e., the blockage of groundwater seepage by the building pile foundation) gradually appears, which intensifies the ground surface settlement. The maximum settlement position of the soil behind the pile foundation of the existing building is farther away from the foundation pit as the soil-blocking effect becomes stronger. The coupling effect of soil-blocking and water-blocking on the ground deformation should be considered in the design of the foundation pit project to get a more reasonable support and dewatering scheme. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Analysis of shield tunnel response to bilateral pit excavation with a focus on perimeter pressure and deformation mechanisms.
- Author
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Mu, Zhiyuan, Wei, Gang, Zhang, Zhiguo, Jiang, Haibo, Xu, Tianbao, and Qi, Yongjie
- Subjects
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BUILDING foundations , *BORED piles , *TUNNELS , *ABSOLUTE value , *TUNNEL design & construction , *EXCAVATION , *ARCHES - Abstract
This study aims to investigate the responses of shield tunnel structures subjected to disturbances caused by bilateral pit excavation, and it systematically reveals for the first time the impact mechanism of bilateral pit excavation on the distribution of perimeter pressure and deformation patterns of shield tunnels. Using a bilateral pit excavation project in Nanjing as a case study, this research establishes methods for calculating longitudinal displacement and circumferential pressure of tunnels under bilateral pit excavation conditions, employing the image source method for analysis. A refined three-ring segment model is developed, and the load structure method is used to analyze the impact of deep foundation excavation on the tunnel located between the two excavation sites. The results indicate that, compared to unilateral excavation, bilateral excavation significantly increases the perimeter pressure at the top and bottom of the tunnel, with a smaller increase in pressure at the arch waist. The deformation pattern is characterized by contraction at the top and bottom and expansion at the waist, forming a transverse elliptical deformation. The maximum vertical convergence values of the middle segment ring are 25.00 mm at the top and 25.88 mm at the bottom, with a vertical absolute convergence value of 44.5 mm and a convergence ratio (ΔDt/Dt) of 0.72%. As the foundation coefficient increases, the perimeter pressure at the top and bottom of the tunnel also increases. When the tunnel is closer to the foundation pits (Sp decreases), the perimeter pressure at the bottom of the tunnel increases. Conversely, as the distance between the two foundation pits (S) increases, the impact of excavation on the tunnel shifts from the upper part to the lower part, resulting in decreased upper perimeter pressure and increased lower perimeter pressure. The research findings provide important references for similar engineering projects. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Study on the Stress and Deformation Laws and Work Principles of the Pull-pile Supporting Structure in a Deep Foundation Pit.
- Author
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Binpeng Lan, Yanping Wang, Weiguo Wang, Yijun Wang, and Ke Ruan
- Subjects
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STRAINS & stresses (Mechanics) , *BUILDING foundations , *BORED piles , *BENDING moment , *DEFORMATIONS (Mechanics) - Abstract
In combination with the field monitoring data, PLAXIS3D finite-element software was used to numerically model the pull-pile supporting structure in a deep foundation pit. This structure was compared to the single-row pile support structure in order to learn more about the pull-pile supporting structure's force and deformation characteristics and how it works. The study found that the cumulative horizontal displacement curves of the supporting piles are integrated into an "upward convex" shape. The bending-moment curve of the front-row piles presents an "inverted S" shape, and the bending-moment curve of the back-pull piles presents a "bow" shape. The "back-pull-pile effect" can improve the unbalanced distribution of positive and negative bending moments in single-row piles by changing the stress condition of the soil. In other words, the pull-pile supporting structure has good safety and serviceability and can well control the lateral displacement of the foundation pit. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Hyperbolic load–displacement analysis of helical and expanded piles: database approach.
- Author
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Rahimi, Amirhossein, Eslami, Abolfazl, and McCartney, John S.
- Subjects
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BUILDING foundations , *HYPERBOLIC functions , *AXIAL loads , *DATABASES , *BORED piles - Abstract
Recent years have witnessed a focus on improving geotechnical systems by implementing and constructing new deep foundations such as helical and expanded piles. In this study, the effects of parameters such as embedment depth, pile geometry and axial loading direction on the load–displacement behaviour of these piles were examined. To this end, a database was compiled consisting of 80 axial loading test records for different piles. The embedment depth of the piles was in the range 2.4–36.8 m and the diameter of the helices (DH) or expanded parts (DEP) was in the range 254–1500 mm. The ultimate load of the piles was determined using the 2.5% and 5% displacement ratio criteria and the Brinch Hansen 80% method. Hyperbolic functions were fitted to the load–displacement curves, allowing for consistent estimation of the limit load and the initial tangent modulus. Analysis of the results from the database revealed that the dominant factors influencing the ultimate load, limit load, maximum measured load, initial stiffness and load–displacement behaviour were the ratio of DH or DEP to the shaft diameter, the shaft area and the toe area, and the load direction. Correlations derived from the database were validated using measurements from eight full-scale helical and expanded piles. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. A nine-year case history of monitoring a wide pile group part I.
- Author
-
Buttling, Stephen, Fellenius, Bengt H., and Pinijpol, Naruedol
- Subjects
- *
DEAD loads (Mechanics) , *SOIL compaction , *BORED piles , *DYNAMIC testing , *NUMERICAL analysis - Abstract
This is the first of two papers on a wide pile group. The geology and a geotechnical model of the site are presented, along with the design of a single pile, analysis of a static loading test, and some dynamic tests. Response of the piled foundations comprising 399 bored piles supporting three 70-storey towers on a common mat was monitored. Records consist of results of a static loading test, dynamic tests of four piles, the development of load in 15 piles, and settlement of 40 points during construction and nine years following. At end of construction, the perimeter piles received more load from the towers than did the interior piles and the mat settled on average 90 mm. By the end of the monitoring period, due to the general subsidence, the average settlement of the mat had increased by 50 mm. Most of the settlement is considered to originate from the compression of the soil layers below the pile toe level. A subsequent paper will present the analysis and design of the wide pile group, and the numerical analysis of the static loading test on a single pile and of the wide pile group. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. 珠三角地区典型淤泥质土硬化土 本构模型参数研究.
- Author
-
王祥秋, 罗晓栋, and 郑土永
- Subjects
- *
BUILDING foundations , *LOADING & unloading , *RIVER engineering , *SOIL mechanics , *BORED piles - Abstract
In order to explore the applicability of the hardening soil constitutive model for numerical analysis of soft soil underground engineering in the Pearl River Delta region, and based on four different stress path triaxial tests, the mechanical properties and variation of constitutive model parameters of hardening soil were analyzed for the typical silty soil in this region. Research results have shown that lateral unloading and drainage conditions have significantly impact on the partial parameters of constitutive model, such as the strength parameters of c' and φ ', the stiffness parameters such as Eref 50, E ref ur and m, but the impact on the failure ratio Rf is relatively small. For the consolidated undrained lateral unloading condition, the main parameters of the constitutive model for typical silty soil in the Pearl River Delta region are shown as the reference secant modulus Eref 50 is 2.34 MPa, with reference to tangent modulus Eref oed is 1.59 MPa, with reference to the loading unloading modulus E ref ur is 11.67 MPa, with a failure stress ratio of Rf is 0.98, and the power exponent m related to stiffness stress level is 1.84; Among them: Eref 50 is 1.47 times of Eref oed, E ref ur is 7.34 times of Eref oed. The practice of a deep foundation pit of soft soil in the Pearl River Delta has proven that the constitutive model of hardening soil is suitable for simulating the mechanical properties of soft soil in this region. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. 船坞坞口基坑的组合围护结构变形实测及 数值分析研究.
- Author
-
杨连佼
- Subjects
- *
BORED piles , *DISPLACEMENT (Mechanics) , *THREE-dimensional modeling , *SHIPBUILDING , *DEFORMATIONS (Mechanics) - Abstract
The dock entrance foundation pit of the No.2 dock project of CSSC shipbuilding base is located on Changxing Island in Shanghai, where the geological conditions are typical soft clays. The excavation depth of the foundation pit is 16.0 m, and a compound retaining system of steel sheet pile and bored pile is adopted to form a supporting structure with 5 levels of struts. In order to study the implementation effect and deformation characteristics of the retaining structures during construction, the lateral displacement characteristics of retaining structure during excavation were analyzed based on the monitoring data of the project. Plus, a three-dimensional numerical model was established to simulate the whole excavating process of the dock entrance foundation pit, and the deformation characteristics were compared and analyzed. The research shows that the measured lateral displacement of the foundation pit retaining structure presents an S-shaped due to the large prestress applied to the steel struts. In view of spatial effect, the lateral displacement on the long side of the foundation pit is greater than that on the short side. Furthermore, the lateral displacement of the steel pile is larger than that of the bored pile due to difference in stiffness. By contrast calculations and actual measurements of lateral displacement, the numerical model can well describe the deformation characteristics of the retaining structure of the dock entrance foundation pit, and to some extent reflect the distribution characteristics of inner forces of the retaining structure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Beton mit 100 % rezyklierter Gesteinskörnung – Erfahrungsbericht zu acht Praxisprojekten.
- Author
-
Wild, Peter, Kustermann, Andrea, and Stengel, Thorsten
- Subjects
- *
RECYCLED concrete aggregates , *MINERAL aggregates , *BORED piles , *EXTERIOR walls , *COMPRESSIVE strength - Abstract
Use of 100 % recycled aggregates in concrete – report on practical applications This article reports on eight practical examples of applications for concrete with 100 % recycled aggregates. The applications include reinforced/unreinforced bored piles, foundations, load‐bearing internal/external walls, columns and floor slabs as well as balcony elements. Some components were realised as architectural concrete components. The respective project is summarised together with the results of the concrete development and concrete testing as well as the experience gained from obtaining special approvals in individual cases. Based on the findings from the various practical projects, it can be concluded that concrete with 100 % RC‐GK can be used for a large number of applications, so far limited to up to XC4 and XF3. Compressive strength for ready‐mix concrete up to C35/45 with good workability even with pumped concrete (here: pumping distance 45 m) using 100 % RC‐GK type 1 were possible without any problems. A concrete with sufficient early strength and a final strength of C40/50 was developed for precast elements. In two examples, RC‐GK type 2 was used for the coarse grain fraction and RC‐GK type 1 for the sand. All the projects presented have already been completed or are nearing completion. The feasibility of 100 % RC concrete in practice has thus been successfully demonstrated in several cases. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Field Study on Bearing Capacity of Large-Diameter Rock-Socketed Bored Piles with Combined Grouting in Highly Weathered Rock Layers.
- Author
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Wan, Zhi-hui, Duan, Chang, Hu, Tao, Zhou, Feng, and Dai, Guo-liang
- Subjects
- *
BORED piles , *DEAD loads (Mechanics) , *WEATHERING , *GEOLOGICAL surveys , *GROUTING , *PILES & pile driving - Abstract
This paper aims to investigate the effect of combined end-and-side grouting on the bearing properties of large-diameter rock-socketed bored piles in highly weathered rock layers. Eight full-scale pile load tests were conducted in the highly weathered rock layer to analyze the enhanced mechanism of the combined grouted bored piles. The test data from pile mechanical testing were compared with the recommended values in the current specification and geological survey report. The results demonstrate significant improvement in the side and end resistances of the combined grouted bored piles, resulting in a substantial increase in the bearing capacity and effective settlement control. It was observed that the construction of impact holes for bored piles can cause severe damage to highly weathered rock structures and weaken the mobilization of side and end resistances. Moreover, it was found that the calculation of the enhancement coefficient in the current specification underestimates the practical bearing capacity. The measured enhancement coefficients for the side and end resistance of piles in fully or highly weathered rock layers range from 2.49 to 3.05 and 2.24 to 2.43, respectively, which are more reasonable and feasible for the calculation. The research findings deepen the understanding of the bearing characteristics of large-diameter rock-socketed bored piles with combined grouting and provide valuable case references for the optimal design of large-diameter combined grouted piles for building foundations in Shenzhen, China. Highlights: Post-grouting had the potential to improve super high-building foundation reliability while reducing pile length and cost. The improvement effect and improvement mechanism of combined grouted bored piles embedded in highly rock strata were revealed. The influence of the size effect for large-diameter piles in highly weathered rock was revealed. The construction of impact holes for bored piles can cause severe damage to highly weathered rock structures and weaken the mobilization of side and end resistances. The enhancement coefficients for the side and end resistance of piles in fully or highly weathered rock layers were proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Study on Spatiotemporal Evolution Laws and Deformation Characteristics of Circular Deep and Large Foundation Pits in Soft Soils.
- Author
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Liu, Hanzhi, Liu, Xinrong, Zhou, Xiaohan, Wang, Linfeng, Wang, Kexiao, Zhang, Jilu, and Guo, Xueyan
- Subjects
- *
DEFORMATION of surfaces , *BORED piles , *SOIL mechanics , *SOIL depth , *SETTLEMENT of structures - Abstract
With the increasing demand for large and deep anchor projects in soft soil areas, issues related to settlement in circular foundation pits and damage to supporting structures have become significantly pronounced. The absence of pertinent design methods significantly impacts construction safety. Through on-site monitoring and statistical analysis, this study examines the spatiotemporal evolution of deformation in circular foundation pits, the deformation characteristics of retaining structures, and surface settlement features. Key design factors influencing the stability of circular foundation pits are explored. The research indicates that structural deformation and surface settlement are closely related over time and exhibit substantial spatial coordination. The deformation control capability of circular foundation pits is considerably stronger than that of square foundation pits, and it is less influenced by excavation depth. Diameter and soft soil thickness have a substantial impact on structural deformation and surface settlement. When the diameter is less than 40 m, the structural deformation remains below 0.1%. The study establishes an evaluation method for the deformation control of large and deep circular foundation pits in soft soil based on a significant amount of engineering monitoring data. It categorizes deformation control indicators for pit excavation based on different design factors, offering reliable theoretical support for relevant design professionals. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Impact of Excavation on Adjacent Elevated Bridges and Optimization Analysis of Deformation Control.
- Author
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Wu, Jiangpeng, Yu, Junping, Fang, Fuguan, Lin, Gang, Tang, Xiaolin, Ding, Haibin, and Xu, Changjie
- Subjects
BUILDING foundations ,BRIDGE foundations & piers ,BORED piles ,SOIL depth ,TRANSIT-oriented development - Abstract
Based on the deep foundation pit project of the TOD (Transit-Oriented Development) complex of the Shaoxing North High-speed Railway Station, the influence of different construction stages on the deformation and inclination rate of the adjacent elevated bridge and its variation law are studied through field measurement and numerical simulation. The construction process is optimized by the method of reinforcement outside the pit and adjustment of preloaded axial force, and the influence of distance on elevated bridges is summarized. The results show that with the excavation of the foundation pit, the deformation of the bridge pier and bridge pile foundation gradually increases, and the deformation of the bridge piers is larger than that of the bridge pile foundations. As the depth of soil reinforcement outside the pit and the preloaded axial force increases, the maximum vertical displacement of the bridge pier and bridge pile foundations gradually decreases. The deeper the depth of soil reinforcement, the better the displacement control effect on the elevated bridge. In actual construction, it is recommended that the depth of reinforcement be taken as the excavation depth of the pit. It is obvious that the preloaded axial force is subject to the pit angle effect, and the appropriate value of the preloaded axial force should be selected according to the site conditions. The deformation of the bridge pier and bridge pile foundation generally shows a decreasing trend with the increase in the distance between the elevated bridge and the foundation pit. When the elevated bridge is close to the foundation pit, it will be affected by the pit angle effect, and the fluctuation will decrease. The conclusions drawn in the article can serve as the basis and reference for design and construction, and provide reference for similar projects. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Seismic Performance Evaluation of Pipelines Buried in Sandy Soils Reinforced with FRP Micropiles: A Numerical Study.
- Author
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Al-Jeznawi, Duaa, Al-Janabi, Musab Aied Qissab, Shafiqu, Qassun S. Mohammed, Jasim, Tiba N., Güler, Erol, Bernardo, Luís Filipe Almeida, and Andrade, Jorge Miguel de Almeida
- Subjects
EARTHQUAKE zones ,BUILDING foundations ,REINFORCED soils ,FIBER-reinforced plastics ,BORED piles - Abstract
Unstable sandy soil poses significant challenges for buried pipelines, particularly due to the increased risk of displacement and stress-induced fractures resulting from soil settlement and earthquake-induced ground deformation. These concerns are especially critical in seismically active regions where underground infrastructure is at higher risk. Fiber-reinforced polymer (FRP) composites present a promising and sustainable alternative for deep foundations, offering durability and reduced maintenance costs compared to conventional materials. This study introduces a novel approach to enhancing the seismic performance of pipelines buried in sandy soils by numerically investigating a three-dimensional (3D) multipipe grouting micro anti-slide pile system, utilizing a polyurethane polymer slurry as the grouting material. Key parameters such as pile spacing, diameter, and length, along with the effects of soil wetting and various earthquake intensities, were examined under the influence of surface loads exerted by a fully loaded truck. The results demonstrate that using polymer micropiles significantly reduces soil and pipeline settlement by 15% to 50%, with larger pile diameters and lengths further decreasing settlement and strain on pipelines. While seismic excitation increases settlement, polymer grouting effectively mitigates this impact, leading to substantial reductions in settlement. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Energy-Efficient Joint Partitioning and Offloading for Delay-Sensitive CNN Inference in Edge Computing.
- Author
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Zha, Zhiyong, Yang, Yifei, Xia, Yongjun, Wang, Zhaoyi, Luo, Bin, Li, Kaihong, Ye, Chenkai, Xu, Bo, and Peng, Kai
- Subjects
BORED piles ,GREEDY algorithms ,EDGE computing ,POWER transmission ,ENERGY consumption ,DEEP learning - Abstract
With the development of deep learning foundation model technology, the types of computing tasks have become more complex, and the computing resources and memory required for these tasks have also become more substantial. Since it has long been revealed that task offloading in cloud servers has many drawbacks, such as high communication delay and low security, task offloading is mostly carried out in the edge servers of the Internet of Things (IoT) network. However, edge servers in IoT networks are characterized by tight resource constraints and often the dynamic nature of data sources. Therefore, the question of how to perform task offloading of deep learning foundation model services on edge servers has become a new research topic. However, the existing task offloading methods either can not meet the requirements of massive CNN architecture or require a lot of communication overhead, leading to significant delays and energy consumption. In this paper, we propose a parallel partitioning method based on matrix convolution to partition foundation model inference tasks, which partitions large CNN inference tasks into subtasks that can be executed in parallel to meet the constraints of edge devices with limited hardware resources. Then, we model and mathematically express the problem of task offloading. In a multi-edge-server, multi-user, and multi-task edge-end system, we propose a task-offloading method that balances the tradeoff between delay and energy consumption. It adopts a greedy algorithm to optimize task-offloading decisions and terminal device transmission power to maximize the benefits of task offloading. Finally, extensive experiments verify the significant and extensive effectiveness of our algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. A STUDY ON THE EFFECT OF TOE-WING POSITION ON SCREW PILE PERFORMANCE IN COHESIONLESS SOIL.
- Author
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Sahil, Ahmad Waheed, Uchimura, Taro, Maejima, Tadashi, and Kabir, Md Raihanul
- Subjects
BEARING steel ,BORED piles ,SPECIFIC gravity ,SCREWS ,TORQUE - Abstract
Over the past 30 years, screw piles with diverse geometries have gained popularity over conventional piles for deep foundations. The behavior of toe-wing screw piles is not widely recognized on a global scale, and the effect of toe-wing plate position on the performance of screw piles has not been explored. Therefore, this paper investigated the impact of toe-wing position on screw pile performance embedded in the bearing layer. The toe-wing plates were embedded (Ew) in the bearing layer at a depth equal to the wing plate diameter, while the embedment depth (Ed) of the central shaft (pile tip) increased from 0 mm to 90 mm, which reflects the change in the toe-wing position. The model ground was prepared in the steel container with bearing layer densities of 55, 80, and 90 %, while the soil above the bearing layer was placed at a relative density of 45 %. The experimental results indicated that the installation load and torque non-linearly increased with the increase in embedment depth ratio (Ed/Ew). However, if checked at the same embedment depth (Ed), the normalized installation load increased to Ed/Ew = 1.2 and then decreased. In contrast, the normalized installation torque is non-linearly reduced with an increased embedment ratio (Ed/Ew). The normalized ultimate pile capacity increased non-linearly with the increase in embedment ratio (Ed/Ew). Regression equations based on the above trends are presented in this study to quantify the effect of Ed/Ew on installation load, torque, and bearing response. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Critical assessment of recent advancements in chitosan-functionalized iron and geopolymer-based adsorbents for the selective removal of arsenic from water.
- Author
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Sirajudheen, P., Vigneshwaran, S., Thomas, Nygil, Selvaraj, Manickam, Assiri, Mohammed A., and Park, Chang Min
- Subjects
WATER disinfection ,TECHNOLOGICAL innovations ,WASTEWATER treatment ,BORED piles ,BIOPOLYMERS ,ARSENIC in water - Abstract
Inorganic arsenic (As), a known carcinogen and major contaminant in drinking water, affects over 140 million people globally, with levels exceeding the World Health Organization's (WHO) guidelines of 10 μg L
−1 . Developing innovative technologies for effluent handling and decontaminating polluted water is critical. This paper summarizes the fundamental characteristics of chitosan-embedded composites for As adsorption from water. The primary challenge in selectively removing As ions is the presence of phosphate, which is chemically similar to As(V). This study evaluates and summarizes innovative As adsorbents based on chitosan and its composite modifications, focusing on factors influencing their adsorption affinity. The kinetics, isotherms, column models, and thermodynamic aspects of the sorption processes were also explored. Finally, the adsorption process and implications of functionalized chitosan for wastewater treatment were analyzed. There have been minimal developments in water disinfection using metal-biopolymer composites for environmental purposes. This field of study offers numerous research opportunities to expand the use of biopolymer composites as detoxifying materials and to gain deeper insights into the foundations of biopolymer composite adsorbents, which merit further investigation to enhance adsorbent stability. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
36. THE WORLD'S LONGEST BRIDGES.
- Author
-
HARVEY, AILSA
- Subjects
UNDERWATER tunnels ,ARTIFICIAL islands ,LOW alloy steel ,BORED piles ,STEEL alloys ,BRIDGES ,HIGH speed trains - Abstract
The article discusses the world's longest bridges and the engineering feats behind them. It highlights the use of high-strength materials, such as advanced steel alloys, in constructing these bridges. The Danyang-Kunshan Grand Bridge in China is currently the longest completed bridge, measuring over 100 miles in length and supporting high-speed trains. Other notable bridges mentioned include the Changhua-Kaohsiung Viaduct in Taiwan, the Tianjin Grand Bridge in China, and the Canakkale Bridge in Turkey. The article also mentions the longest pedestrian bridge, the Sky Bridge 721 in the Czech Republic, and the longest floating bridge, the Evergreen Point Floating Bridge in Washington. Additionally, it discusses the Hong Kong-Zhuhai-Macau Bridge, the world's sixth longest bridge, and the Krämerbrücke Bridge in Germany, the world's longest inhabited bridge. The article concludes with information about the Russky Bridge in Russia, the longest cable-stayed bridge. [Extracted from the article]
- Published
- 2024
37. The Institute’s Dark Secret.
- Author
-
Ciccone, Madeline
- Subjects
EYE contact ,GREENHOUSE gardening ,BORED piles ,FULL moon ,FAIRIES ,GAZE - Abstract
The article explores the ethical dilemma surrounding the treatment of faeries in the field of alchemy. Simone and Nikolas, two researchers, have differing perspectives on the matter. Simone believes that faeries have inherent worth and should not be imprisoned for human benefit, while Nikolas sees them as a means to an end. Simone takes action by closing a portal used to trap faeries, going against her oath to the Institute. The text raises questions about ethics, the value of different creatures, and the breaking of promises. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
38. Introducing Cement-Enhanced Clay-Sand Columns under Footings Placed on Expansive Soils.
- Author
-
Shaker, Abdullah A. and Dafalla, Muawia
- Subjects
SWELLING soils ,SOIL cement ,CLAY ,BORED piles ,COMPRESSIVE strength - Abstract
The risk posed by expansive soils can be lessened by placing foundations at a more deep level below the surface. Structures are able to withstand uplift forces because overburden pressure partially suppresses swelling pressure. In order to transfer the forces to a sufficiently deep depth, this study suggests introducing shafts of a low-expansion overburden material. Soil improved with cement is chosen for this purpose. This study suggests using sand with added excavated natural clay and cement. The expansive clay is added to sand in ratios of 10, 20, 30, 40 and 60%. The clay–sand mixture is then enhanced by cement of 1, 2, 4 and 8% by the weight of the mixture under four curing periods of 1, 7, 28, and 90 days. This material is recommended for use under lean concrete to transfer the loads to lower levels below the foundation depth. The thickness of this material depends on the stresses exerted, the type and the properties of the subsurface soils. The cement-enhanced clay–sand shaft's properties are examined in this work with regard to the swelling potential, compressibility, and the unconfined compressive strength for different clay contents and curing conditions. Stiff shafts were formed and found to support stresses from 600 to 3500 kPa at cement additions in the range of 1% to 8%. Clay content above 30% is found to be not suitable for Al-Qatif clay due to the compressibility and low strength of the mixture. When two percent or more of cement is added, the swelling potential is significantly reduced. This is reliant on the pozzolanic interactions of soils and cement as well as the clay mineralogy. Determining how cement affects clay–sand combinations in regions with expansive soils would facilitate the introduction of a novel, inexpensive technology to support loads applied by the superstructure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Distinguishing word identity and sequence context in DNA language models.
- Author
-
Sanabria, Melissa, Hirsch, Jonas, and Poetsch, Anna R.
- Subjects
- *
LANGUAGE models , *KNOWLEDGE representation (Information theory) , *DEEP learning , *BORED piles , *HUMAN genome - Abstract
Transformer-based large language models (LLMs) are very suited for biological sequence data, because of analogies to natural language. Complex relationships can be learned, because a concept of "words" can be generated through tokenization. Training the models with masked token prediction, they learn both token sequence identity and larger sequence context. We developed methodology to interrogate model learning, which is both relevant for the interpretability of the model and to evaluate its potential for specific tasks. We used DNABERT, a DNA language model trained on the human genome with overlapping k-mers as tokens. To gain insight into the model′s learning, we interrogated how the model performs predictions, extracted token embeddings, and defined a fine-tuning benchmarking task to predict the next tokens of different sizes without overlaps. This task evaluates foundation models without interrogating specific genome biology, it does not depend on tokenization strategies, vocabulary size, the dictionary, or the number of training parameters. Lastly, there is no leakage of information from token identity into the prediction task, which makes it particularly useful to evaluate the learning of sequence context. We discovered that the model with overlapping k-mers struggles to learn larger sequence context. Instead, the learned embeddings largely represent token sequence. Still, good performance is achieved for genome-biology-inspired fine-tuning tasks. Models with overlapping tokens may be used for tasks where a larger sequence context is of less relevance, but the token sequence directly represents the desired learning features. This emphasizes the need to interrogate knowledge representation in biological LLMs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Self‐supervised representation learning of metro interior noise based on variational autoencoder and deep embedding clustering.
- Author
-
Wang, Yang, Xiao, Hong, Zhang, Zhihai, Guo, Xiaoxuan, and Liu, Qiang
- Subjects
- *
ARTIFICIAL neural networks , *CONVOLUTIONAL neural networks , *DATA augmentation , *BORED piles , *WAVELET transforms - Abstract
The noise within train is a paradox; while harmful to passenger health, it is useful to operators as it provides insights into the working status of vehicles and tracks. Recently, methods for identifying defects based on interior noise signals are emerging, among which representation learning is the foundation for deep neural network models to understand the key information and structure of the data. To provide foundational data for track fault detection, a representation learning framework for interior noise, named the interior noise representation framework, is introduced. The method includes: (i) using wavelet transform to represent the original noise signal and designing a soft and hard denoising module for dataset denoising; (ii) deep residual convolutional denoising variational autoencoder (VAE) module performs representation learning with a VAE and deep residual convolutional neural networks, enabling richer data augmentation for sparsely labeled samples by manipulating the embedding space; (iii) deep embedding clustering submodule balances the representation of reconstruction and clustering features through the joint optimization of these aspects, categorizing metro noise into three distinct classes and effectively discriminating significantly different features. The experimental results show that, compared to traditional mechanism‐based models for characterizing interior noise, this approach offers a data‐driven general analysis framework, providing a foundational model for downstream tasks. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Beitrag zur Durchmesserbestimmung an Pfählen auf der Grundlage des Thermal Integrity Profiling.
- Author
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Kindler, Arne and Lübben, Jasper
- Subjects
- *
BORED piles , *GEOTECHNICAL engineering , *ENGINEERING simulations , *DIAMETER , *CONFERENCES & conventions - Abstract
Contribution to determining the diameter of piles based on thermal integrity profiling When carrying out thermal integrity profiling (TIP), it is often said that the profiling serves, among other things, to determine the cubature of the pile created. In the relevant publications on TIP, Pile Dynamics, Inc., among others, points out that this is only an estimate of the concrete cover or excess concrete during pile production. In particular, in this case it is assumed that the installed concrete volume must also be monitored in order to contrast this with the measurement results. However, from the authors′ point of view, this alone is not enough to draw a well‐founded conclusion about the pile cubature from the temperature records. This approach appears to be problematic, particularly with special shapes. As part of the 17th Hans Lorenz Symposium 2023 at the Technical University of Berlin, the first "New findings on Thermal Integrity Profiling (TIP) on deep piles with special shapes" were presented. These findings were expanded upon as part of further investigations using the commercial software COMSOL Multiphysics and are presented in more detail below. The result is that the influencing factors are so diverse that even if they are taken into account, no conclusions can be drawn about the diameter. This is clearly presented by the authors below. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Study of the Side Resistance of Bored Piles in Rock.
- Author
-
Sharafutdinov, R. F. and Botanin, D. P.
- Subjects
- *
BORED piles , *TEST design , *ROCK testing , *COMPRESSIVE strength , *EMPIRICAL research - Abstract
The results of over 100 bored pile tests embedded in rock have been analyzed. A comparison with a large amount of published data on pile test results in construction sites from the USA, Canada, Hong Kong, Turkey, and other regions is presented. A pile strain index classification based on relative pile displacement was proposed. The ranges of mobilized side resistance of piles for different strain indexes were determined. The relationship between the side resistance of bored piles in rock and the unconfined compressive strength and strain values was obtained. The proposed relationship was compared with available published data and existing empirical methods. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Calculation of Long Bored Piles for Vertical Loading.
- Author
-
Gotman, A. L. and Gavrikov, M. D.
- Subjects
- *
BORED piles , *CLAY soils , *SOIL formation , *COMPRESSIBILITY , *SOILS - Abstract
The results of tests of vertically loaded long bored piles in clayey soils by the immersion jack method are obtained. The peculiarities of soil resistance formation under the lower end and along the lateral surface of piles are shown. The necessity of calculation of such piles on the soil by the second limit state with consideration of the pile shaft compressibility is substantiated. A methodology for calculating the settlement of a single pile and determining the allowable load thereon at a given settlement of the pile head based on the kinematic scheme of including the soil base and the pile shaft in the work upon pile loading is developed. The results of numerical studies on the basis of pile tests on an actual object are presented. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. 钻孔桩泥浆脱水特性研究.
- Author
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罗伟 and 李世汩
- Subjects
- *
BORED piles , *SCANNING electron microscopes , *CONCRETE mixing , *WATER pressure , *MUD - Abstract
Taking the bored pile mud of Shuangliu Yangtze River Bridge on Xingang Expressway as the research object,different mud of the same bored pile were selected to carry out flocculation settlement test and medium pressure filtration test,and the mud sludge specific resistance (SRF) and capillary water absorption time (CST) under different water content werecompared. Particle size analyzer, scanning electron microscope and X-ray diffraction were used to analyze the composition inthe mud, the dehydration performance and influencing factors of bored pile mud were studied to explore the factors affecting thedehydration performance. The results show that the settlement performance of bored pile mud is poor, and the addition of PAMhas no significant effect on the improvement of settlement performance. Mud water loss based on medium pressure water lossinstrument can reflect the mud settling performance. There is a certain linear correlation between SRF and CST of the test mud,and the correlation size is affected by the mud dehydration performance, the more difficult it is to dehydrate, the better thecorrelation. Among the characteristic particle size of mud, D50 particle size has the greatest influence on the mud dehydrationcharacteristics. Mixing with concrete has the effect of increasing the particle size of mud D50 and above, and increasing thecontent of Ca, Mg, Si, and Fe elements in the mud to improve its dehydration performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Targeting Inflammatory Lesions Facilitated by Galactosylation Modified Delivery System Eudragit/Gal-PLGA@Honokiol for the treatment of Ulcerative Colitis.
- Author
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Wang, Anqi, Liu, Yuanyuan, Xiong, Wugui, Li, Wei, Li, Jin, Yang, Zhiqiang, Zou, Zhongtao, Luo, Yinjia, Chen, Zhoujiang, Li, Hanmei, Vong, Chi Teng, and Zou, Liang
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ORAL drug administration , *ULCERATIVE colitis , *COUPLING reactions (Chemistry) , *BORED piles , *HERBAL medicine , *ZETA potential - Abstract
Honokiol (HNK) is one of the bioactive ingredients from the well-known Chinese herbal medicine Magnolia officinalis , and its research interests is rising for its extensive pharmacological activities, including novel therapeutic effect on ulcerative colitis (UC). However, further application of HNK is largely limited by its unique physicochemical properties, such as poor water solubility, low bioavailability, as well as unsatisfied targeting efficacy for inflammatory lesions. In this study, we constructed galactosylation modified PLGA nanoparticles delivery system for efficient target delivery of HNK to the colitic lesions, which could lay a research foundation for the deep development of HNK for the treatment of UC. D-galactose was grafted by chemical coupling reactions with PLGA to prepare Gal-PLGA, which was used as a carrier for HNK (Gal-PLGA@HNK nanoparticles (NPs)). To improve the colon targeting efficiency by oral administration of the NPs, Eudragit S100 was used for wrapping on the surface of Gal-PLGA@HNK NPs (E/Gal-PLGA@HNK NPs). Our results showed that the encapsulation efficiency and drug loading capacity of E/Gal-PLGA@HNK NPs were 90.72 ± 0.54% and 8.41 ± 0.02%, respectively. Its average particle size was 242.24 ± 8.42 nm, with a PDI value of 0.135 ± 0.06 and zeta-potential of -16.83 ± 1.89 mV. The release rate of HNK from E/Gal-PLGA@HNK NPs was significantly decreased when compared with that of free HNK in simulated gastric and intestinal fluids, which displayed a slow-releasing property. It was also found that the cellular uptake of E/Gal-PLGA@HNK NPs was significantly increased when compared with that of free HNK in RAW264.7 cells, which was facilitated by D-galactose grafting on the PLGA carrier. Additionally, our results showed that E/Gal-PLGA@HNK NPs significantly improved colonic atrophy, body weight loss, as well as reducing disease activity index (DAI) score and pro-inflammatory cytokine levels in UC mice induced by DSS. Besides, the retention time of E/Gal-PLGA@HNK NPs in the colon was significantly increased when compared with that of other preparations, suggesting that these NPs could prolong the interaction between HNK and the injured colon. Taken together, the efficiency for target delivery of HNK to the inflammatory lesions was significantly improved by galactosylation modification on the PLGA carrier, which provided great benefits for the alleviation of colonic inflammation and injury in mice. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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46. Effectiveness of machine learning at modeling the relationship between Hi‐C data and copy number variation.
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Wang, Yuyang, Sun, Yu, Liu, Zeyu, Chen, Bijia, Chen, Hebing, Ren, Chao, Lin, Xuanwei, Hu, Pengzhen, Jia, Peiheng, Xu, Xiang, Xu, Kang, Liu, Ximeng, Li, Hao, and Bo, Xiaochen
- Subjects
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CHROMATIN , *CHROMOSOMES , *BORED piles , *DNA copy number variations , *DEEP learning - Abstract
Copy number variation (CNV) refers to the number of copies of a specific sequence in a genome and is a type of chromatin structural variation. The development of the Hi‐C technique has empowered research on the spatial structure of chromatins by capturing interactions between DNA fragments. We utilized machine‐learning methods including the linear transformation model and graph convolutional network (GCN) to detect CNV events from Hi‐C data and reveal how CNV is related to three‐dimensional interactions between genomic fragments in terms of the one‐dimensional read count signal and features of the chromatin structure. The experimental results demonstrated a specific linear relation between the Hi‐C read count and CNV for each chromosome that can be well qualified by the linear transformation model. In addition, the GCN‐based model could accurately extract features of the spatial structure from Hi‐C data and infer the corresponding CNV across different chromosomes in a cancer cell line. We performed a series of experiments including dimension reduction, transfer learning, and Hi‐C data perturbation to comprehensively evaluate the utility and robustness of the GCN‐based model. This work can provide a benchmark for using machine learning to infer CNV from Hi‐C data and serves as a necessary foundation for deeper understanding of the relationship between Hi‐C data and CNV. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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47. Evaluation and Optimization of the Corner Effect of a Deep Foundation Pit Adjacent to a Subway Tunnel.
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Dong, Xin, Zhou, Feng, Chen, Tingzhu, Zhu, Rui, and Wang, Xudong
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BUILDING foundations , *BORED piles , *SUBWAY tunnels , *WATER pressure , *CONSTRUCTION costs , *QUARRIES & quarrying , *PILES & pile driving - Abstract
The prevailing design methodology for foundation pit support structures conventionally treats the pit cross section as a two-dimensional plane, facilitating the computation of soil and water pressures acting upon the retaining structure. Regrettably, this conventional approach tends to overlook the critical corner effect, particularly when the foundation pit is in proximity to a subway tunnel, where the nuanced nature of this corner effect remains indeterminate. Consequently, this research is directed toward an in-depth investigation of a deep foundation pit contiguous to a subway tunnel. A systematic evaluation and optimization of the corner effect pertaining to the deep foundation pit are undertaken through a combination of comprehensive field monitoring and simulation methodologies. The results show that a substantial mitigation in the deformation of the supporting structure, settlements of the ground surface and adjacent buildings, as well as the displacement of the subway tunnel, were achieved through a consideration of the corner effect. Notably, the ameliorative impact of adjacent buildings on the corner effect is observed. Further scrutiny reveals that the supporting structure within a distance of 12 m from the pit corner is most susceptible to the corner effect, as evidenced by a plane strain ratio (PSR) falling below 0.8. Beyond a spatial threshold of 20 m, the PSR attains a value of 1.0, indicative of a negligible corner effect and the foundation pit section existing in a plane strain state. The adjustment of pile length or diameter based on the PSR emerges as a viable strategy that can realize the construction cost optimization on the premise of ensuring the stability of the foundation pit. The impact of pile diameter variation is paramount, corresponding to a reduction in the range of PSR values below 0.8 from 12 m to 9.8 m. The corner effect is significantly diminished. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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48. Christian Humanism and Christianity-Inspired Atheistic Humanism.
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VAŠEK, MARTIN
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PHILOSOPHY of religion ,BORED piles ,HUMANISM ,ATHEISM ,PHILOSOPHERS - Abstract
The aim of this study is to focus on two forms of humanism: atheistic humanism (or humanistic atheism) and Christian humanism. The first type is represented by Czech philosopher Otakar A. Funda, while the second type is represented by two Christian thinkers - Jolana Poláková and Richard Schaeffler. By examining humanistic atheism, we can understand the distinctiveness and uniqueness of Christian humanism. In particular, I will highlight two aspects of Christian humanism: the concept of heteronomy and the concept of hope. I believe that one of the important roles of religion, especially Christianity, today is to contribute to the development of a humanism that emphasizes hope and the liberating heteronomy of God. Additionally, we can question whether, in a time of potential threats or even the possibility of the extinction of the human species, the "earthly" reasons for "why keep on giving life?" are sufficiently convincing and valid, or if they require a deeper foundation. [ABSTRACT FROM AUTHOR]
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- 2024
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49. Advanced Risk Assessment for Deep Excavation in Karst Regions Using Improved Dempster–Shafer and Dynamic Bayesian Networks.
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Lei, Zhenyu, Wang, Yanhong, Zhang, Yu, Gu, Feng, Zan, Zihui, Mei, Yuan, Liu, Wenzhan, and Zhou, Dongbo
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BUILDING foundations ,BORED piles ,BAYESIAN analysis ,RISK assessment ,INFORMATION resources - Abstract
This study presents a novel risk-assessment methodology for deep foundation pit projects in karst regions, aimed at enhancing project safety and decision-making processes. This approach amalgamates fuzzy dynamic Bayesian networks with a refined Dempster–Shafer (DS) evidence theory to tackle the intricate uncertainties present in such contexts. A comprehensive risk index system, derived from historical accident cases, relevant standards, and the literature, encompasses environmental, design, construction, and management factors. Initial probabilities for each risk factor are determined through the integration of expert knowledge and fuzzy theory. The enhanced Dempster–Shafer theory is utilized to fuse diverse information sources, culminating in a robust and dynamic risk evaluation model. This model leverages real-time monitoring data to dynamically assess and adjust risk levels throughout the construction process. The validation of the proposed method is demonstrated through a detailed case study of the Guangzhou Tangxi Section 1 deep foundation pit project, which effectively identified critical risk factors and facilitated proactive construction strategy adjustments. To further evaluate the reliability of the methodology, comparisons were made with three alternative methods, and applications were conducted on three additional deep foundation pit projects. These comparative analyses confirm the superior reliability and applicability of the proposed methodology across varied scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. A Multi-Objective Prediction XGBoost Model for Predicting Ground Settlement, Station Settlement, and Pit Deformation Induced by Ultra-Deep Foundation Construction.
- Author
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Huang, Guangkai, Liu, Zhijian, Wang, Yajian, and Yang, Yuyou
- Subjects
BUILDING foundations ,BORED piles ,PREDICTION models ,MACHINE learning ,ELECTRONIC data processing ,DEEP learning - Abstract
Building a deep foundation pit in urban centers frequently confronts issues such as closeness to structures, high excavation depths, and extended exposure durations, making monitoring and prediction of the settlement and deformation of neighboring buildings critical. Machine learning and deep learning models are more popular than physical models because they can handle dynamic process data. However, these models frequently fail to establish an appropriate balance between accuracy and generalization capacity when dealing with multi-objective prediction. This work proposes a multi-objective prediction model based on the XGBoost algorithm and introduces the Random Forest Bayesian Optimization method for hyperparameter self-optimization and self-adaptation in the prediction process. This model was trained with monitoring data from a deep foundation pit at Luomashi Station of Chengdu Metro Line 18, which are characterized by a sand and pebble stratum, cut-and-cover construction, and a depth of 45.5 m. Input data of the model included excavation rate, excavation depth, construction time, shutdown time, and dewatering; output data included settlement, ground settlement, and pit deformation at an operating metro station only 5.7 m adjacent to the ongoing pits. The training effectiveness of the model was validated through its high R
2 scores in both training and test sets, and its generalization ability and transferability were evaluated through the R2 calculated by deploying it on adjacent monitoring data (new data). The multi-objective prediction model proposed in this paper will be promising for monitoring the data processing and prediction of settlement of surrounding buildings for ultra-deep foundation pit engineering. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
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