Search

Through analysing a significant number of case histories, ranges of applications of dewatering techniques for randomly fractured rock are proposed in terms of the rock mass permeability and the required drawdown. The cases analysed, which cover a wide range of construction activities and associated dewatering depths, provide one of the most comprehensive studies of dewatering techniques on randomly fractured rock to date. Comparison of the ranges suggested for dewatering in fractured rocks with those developed for excavations in soils is presented. To fit the construction dewatering systems in rock, a modification is proposed for the drawdown diagram that is widely used in practice for soils, and for the limited available general recommendations presented for chalk. Consequently, recommendations are made to improve the procedure of designing and executing these systems. In addition, a dewatering technique is proposed, which allows for construction to proceed in a wet condition, taking into account rock shear strength and the excavation geometry. [ABSTRACT FROM AUTHOR]

The construction industry constantly pursues innovative methods to improve safety, enhance productivity, and reduce costs and project durations. Augmented Reality (AR) is a promising technology, potentially bringing about changes in construction. AR can be useful for visualizing data in construction sites and preventing clashes or accidents. One of its potential applications is in the excavation sector. This research aims to understand the needs, expectations, and challenges associated with adopting AR in the excavation sector. We aim to assess how different AR solutions are perceived and how they would be used. In this work, we draw insights from interviews carried out with 31 professionals in New Zealand's excavation industry. During the interviews, participants interacted with two AR prototypes, which were the same AR application delivered by two AR devices: optical-see-through (OST) and video-see-through (VST). Participants were asked to provide feedback on the implications of AR to the real-world excavation practice and compare the two AR devices. The findings of this study indicate a preference among participants for AR applications compared with traditional paper-based drawings. Participants leaned toward VST among AR devices, given their familiarity with VST devices such as tablets. Further, accessibility emerged as the primary barrier to adopting AR within the excavation industry. As such, this work provides insight for future AR development and prototyping for the excavation industry. [ABSTRACT FROM AUTHOR]

Since the plasticity of soil and the irregular shape of the excavation, the efficiency and stability of the traditional local radial basis function (RBF) collocation method (LRBFCM) are inadequate for analyzing three-dimensional (3D) deformation of deep excavation. In this work, the technique known as the direct method, where the local influence nodes are collocated on a straight line, is introduced to optimize the LRBFCM. The direct method can improve the accuracy of the partial derivative, reduce the size effect caused by the large length-width ratio, and weaken the influence of the shape parameters on the LRBFCM. The mapping technique is adopted to transform the physical coordinates of a quadratic-type block to normalized coordinates, in which the deformation problem can easily be solved using the direct method. The stability of the LRBFCM is further modified by considering the irregular shape of 3D excavation, which is divided into several quadratic-type blocks. The soil's plasticity is described by the Drucker-Prager (D-P) model. The improved LRBFCM is integrated with the incremental method to analyze the plasticity. Five different examples, including strip excavations and circular excavations, are presented to validate the proposed approach's efficiency. [ABSTRACT FROM AUTHOR]

This paper investigates the use of the BOTDA (Brillouin Optical Time-Domain Analysis) technology to monitor a large-scale bored pile wall in the field. Distributed fiber optic sensors (DFOSs) were deployed to measure internal temperature and strain changes during cement grouting, hardening, and excavation-induced deformation of a secant pile wall. The study details the geological conditions and DFOS installation process. During grouting, the temperature increased by approximately 69 °C due to cement hydration 30 min post-grouting, while the strain decreased by 0.5% on average due to cement slurry shrinkage. During excavation, the temperature changes were minimal, but the excavation depth significantly influenced the strain distribution, with continuous compressive deformation observed in two monitored boreholes. Two analytical methods, the numerical integration method (NIM) and the finite difference method (FDM), were used to calculate the lateral pile displacement based on the monitored strain data. The results were compared with previous monitoring data, showing that the lateral displacement of the pile was minimal after excavation and was attributed to the high stiffness of the secant pile wall. This study demonstrates the effectiveness of DFOSs and BOTDA technology for monitoring complex pile wall behaviors during construction. [ABSTRACT FROM AUTHOR]

Although considerable research has explored the static and seismic bearing capacity of strip footings on slopes or excavations, the influence of clay strength anisotropy on the bearing capacity of strip footing near excavations, specifically considering pseudo‐dynamic conditions, remains unexplored. This study used the finite element limit analysis (FELA) method to evaluate the impact of clay strength anisotropy on the seismic bearing capacity of strip footings. The effects of various dimensionless parameters on the bearing capacity were examined, which include shear wavelength, the setback distance ratio, vertical height ratio, soil strength ratio, soil strength heterogeneity, anisotropic ratio, and horizontal and vertical acceleration coefficients. Design charts were developed to compute the seismic bearing capacity of strip footings on nonhomogeneous and anisotropic excavations under pseudo‐static conditions. Furthermore, the effects of vertical acceleration coefficients and shear wavelength on the seismic bearing capacity of strip footing near excavation in nonhomogeneous and anisotropic soils were investigated. [ABSTRACT FROM AUTHOR]

One of the most crucial tasks in the design, control, and construction of urban deep excavations is ensuring the safety of the existing underground infrastructure. Deformation and settlement created by excavation may damage the adjacent tunnels. In this study, the stability of an existing triple tunnel in relation to the construction of an adjacent deep excavation is evaluated by numerical simulation using both the discrete-element method (DEM) and the finite-element method (FEM). A deep excavation supported by the retaining wall and five levels of strutting system was created adjacent to an existing triple tunnel. The excavation's width and depth were 30 and 16 m, respectively. In both discrete-element (DE) and finite-element (FE) simulations, the horizontal spacing of the triple tunnel wall relative to the retaining wall (SH) is varied between 3 and 35 m, while vertical spacing of the triple tunnel's crown from the ground surface (SV) is changed from 4.8 to 32 m. The results indicated that at a certain value of SV and with increasing the SH, the horizontal displacement of the wall decreases. The variations in the triple tunnel position significantly affected the settlement pattern. In addition, the results showed that the maximum vertical displacement occurred at the middle tunnel crown, while the lowest value of the maximum vertical displacement was found at the crown of the right tunnel. At a certain value of the vertical displacement, the wall horizontal displacement is deduced by increasing in the SH value. [ABSTRACT FROM AUTHOR]

Taking the conducted model test by authors as the research object, this paper first carries out detailed numerical analysis and verifies the reliability of the established model. Furthermore, the test phenomenon is explained based on numerical analysis, while parameter analysis is carried out, which mainly includes soil deformation between piles and soil deformation inside and outside excavation. The research results show that when the inclination angle of the piles is small (such as 10°), all or most of the soil (the range of the pile top to 0.6L) between the piles is compressed in the horizontal direction, and the piles and the soil between the piles can be regarded as a whole. When the inclination angle of the piles is large (such as 20°), all or most of the soil (the range of the pile top to 0.6L) between piles is in a relaxed state in the horizontal direction, and the piles deform independently. The research results also show that the maximum displacement of the soil on the surface outside the excavation occurs around the retaining pile, and the displacement distribution patterns change with different types of retaining structures and inclination angle. [ABSTRACT FROM AUTHOR]

Ground subsidence is one of geohazards, particularly in urban environment due to its negative impact to nearby buildings and civil infrastructures. This study investigates the amount and spatial distribution of ground subsidence in Incheon City, South Korea, where ground excavation was made. Interferometric Synthetic Aperture Radar (InSAR) was used to monitor surface deformation around the excavation site. The study analyzed subsidence during an excavation project using Sentinel-1b satellite data, and the InSAR results were compared with traditional leveling methods and field measurements. Notable subsidence during the early construction phase was identified, which demonstrates the effectiveness of InSAR in urban environment. The research contributes to understanding of the excavation-inducing ground subsidence due to the reclamation layer. [ABSTRACT FROM AUTHOR]

The code requirements on drawing up construction design documents do not provide any method of evaluating the mechanical facilities for compliance with the requirements of a construction project. This work is aimed at determining the effective excavator radius, which ensures compliance with the process cycle set by the project. The effective radius of an excavator is the base for designing the excavator working face. A digital model describing each excavator process cycle on one extraction site (working face) has been used as the research tool. Mathematical expressions have been obtained for determining the duration of each excavator process cycle for operation on one extraction site (working face). An area for further studies is identified that consists in theoretically underpinning the position of a bucket discharge point. [ABSTRACT FROM AUTHOR]

When excavating tunnels in urban areas with shallow overburden in poor rock mass, the deformations are very pronounced, which can result in serious potential risks to the safety, costs and time of tunnel construction. In the Kobilja Glava tunnel, which will be part of the project connecting Vogošća with Sarajevo and connecting the city center of Sarajevo with the A1 motorway on Corridor Vc, monitoring of displacements was conducted in a specific section of the left tunnel tube over a length of 80 m, in terms of various distances between the top heading excavation and the primary invert in poorer rock mass with a defined RMR ranging from 27 to 32. The results indicate that displacements can be effectively controlled by defining the optimal distance between the excavation phases of the top heading and the primary invert. A detailed analysis of the collected data yielded a mathematical function relating displacement to the distance between the excavation of the top heading and the primary invert, which can serve as a tool for quick and straightforward correlation of displacements during tunnel excavation, considering the geological conditions present in the Kobilja Glava tunnel. [ABSTRACT FROM AUTHOR]

Measurements of slope displacements can be effective tools for the early warning of the collapse of slopes under excavation in construction projects in mountainous areas, while evaluating of instability based on measured displacement has not yet been accomplished for slopes under excavation. Measurements of displacements on sandy soil slopes under multistep excavation were made, and the measured data were analyzed to determine the characteristics of creep deformation of the slope during and after the excavation and to establish a procedure for evaluating instability of the slope under excavation in this paper. The following facts were derived from the examination of the measured data. Displacement was generated significantly in the latter stage of excavation, and it was generated not only during excavation but also after excavation. The ratio of the displacement after excavation to that from the start of the excavation to the start of the next excavation became larger as the displacement developed immediately before failure. It indicates that creep displacement after the excavation was more significant at latter excavation just prior to failure. The normal displacement converged to constant as the shear displacement increased under a steady state immediately before the failure in direct shear conditions, and the normal displacement can be an indicator of the instability of the slope. The normal displacement cannot remain constant when the inclination of the slope surface is different from that of the slip surface in the excavated slope in this paper. Different indicators are necessary in this case. The angle α between the slope surface and synthetic displacement (RD) on the slope derived from measured data was introduced instead of normal displacement. The synthetic displacement (RD) on the slope indicated the scalar of the synthesis of the displacements normal and downward to the surface of the slope and surface displacement. It converged to constant after excavation immediately before failure, and shear displacement showed an accelerative increase for constant α. This indicated that the angle α could be an indicator of the instability of the slope. This result showed that the angle α being constant indicated that the stress condition was almost in failure and the displacement increased acceleratively. Further examinations based on the measured data on other slope under excavation should be necessary for confirming the results in this paper based on only a case of experiment. [ABSTRACT FROM AUTHOR]

When most of the papyri that Ulrich Wilcken had excavated at Ahnās (Heracleopolis Magna) in 1899 were destroyed by fire, the Berlin Museum decided to use the insurance money to buy more papyri in Egypt, the so-called „Ehnas-Ersatz". Editing new archive documents, the article traces the history of this group of papyri from the fire to their edition and partial return to Cairo. [ABSTRACT FROM AUTHOR]

To investigate the influence of block on the stress and deformation of underground cavern with high sidewall during excavation and unloading, a physical model test of an underground cavern containing block was conducted based on similarity theory. The response pattern of surrounding rock stress and displacement during excavation is analyzed, and the influence and mechanism of block on surrounding rock stress and deformation are revealed. Results show that stress conduction in the model is closely related to the structural plane during loading. The stress barrier and stress concentration phenomena occur when stresses pass through the structural plane. After the model is loaded, stress loss takes place when stresses are transmitted from the boundary to the interior. During the underground cavern excavation, the tangential stress of the surrounding rock decreases within a certain range of the sidewall and increases at both the top and the shoulder of the arch. The change rate of stress before and after excavation is used as an index to determine the surrounding rock stress zone, and the influence range caused by excavation is 2.0–2.5 times the cave span. Compared with the sidewall without block, the sidewall with block has a smaller radial stress unloading zone and a larger tangential unloading zone. [ABSTRACT FROM AUTHOR]

This paper presents observed arching-induced ground deformation and stress redistribution behind braced excavation using the top-down construction method. The soil properties around the excavation were determined by laboratory and field tests. The ground deformation, soil displacement vector, strain path, principal strain, maximum shear strain, lateral earth pressure, pore water pressure, and effective stress path are presented based on the measured data. The majority of soil behind the wall is under volumetric expansion, indicating consolidation, creep behavior, or a combination of both. Besides, two periods of increases in pore pressure are observed, due to stress transfer from the lower to the upper parts (i.e., soil arching effect). The deep inward movement of the wall and the nearby soil accounts for the distribution of lateral earth pressure acting on the wall. The soil located behind the area of maximum wall deformation and adjacent to the wall, as well as the soil below the excavation base intersected by the shear plane, is in an active stress state. The lateral earth pressure at 5 m from the left excavation wall showed minimal changes, due to the combined effects of soil arching from lateral excavation and shield tunneling. [ABSTRACT FROM AUTHOR]

This paper describes the monitoring of the construction of a deep underground waste storage bunker for the PROTOS energy-from-waste facility in Chester, UK. A key element of the construction process was a 12 m deep excavation in soft clays and peats which was supported by a complex 'combi-wall' cofferdam comprising alternate tube and sheet piles, a reinforced concrete (RC) capping beam and two levels of internal bracing. The permanent bunker RC structure was constructed within the excavation using a bottom-up approach. The primary aim of this monitoring programme was to assess the performance of the composite support system through measured cofferdam wall deflections, bracing member loads, and site and bunker water levels. An additional objective of the monitoring was to provide the site team with real-time feedback to inform the construction process. Interpretation of the monitored data allows for a quantitative assessment of the influence of various construction activities on the responses of the support system. The monitored behaviour shows that the high stiffness and embedment depth of the supporting structure, combined with careful control of groundwater levels, significantly reduced risks associated with deep excavation construction in challenging ground conditions. [ABSTRACT FROM AUTHOR]

This paper presents a surrogate-based Bayesian approach for updating the ground parameters within an application of the observational method in sequential excavation method (SEM) construction. A three-dimensional (3D) finite-difference model is used in the forward analysis to simulate SEM construction explicitly considering 3D multi-face excavation effects and ground–structure interaction. The polynomial-chaos Kriging (PCK) method was employed to provide a surrogate for the 3D finite-difference model to alleviate the cost of probabilistic analysis. The uncertain geotechnical parameters are updated during SEM construction through a progressive Bayesian updating procedure. Time-series observations of multiple types of measurements are used to form the likelihood function. The posterior distributions of the uncertain parameters are derived from the affine invariant ensemble sampling (AIES) algorithm. The proposed framework is illustrated through application to data from the Regional Connector Transit Corridor (RCTC) crossover cavern project constructed in downtown Los Angeles. The uncertainties of the geotechnical parameters were substantially reduced. The posterior estimations indicate higher elastic modulus and cohesion of the Fernando formation than what was assumed before the construction. The updated predictions of the ground surface, subsurface and structural deformations showed improvement in agreement with the field measurements through the continuous updating process. [ABSTRACT FROM AUTHOR]

We present the excavation results from a Middle Neolithic site associated with the Funnel Beaker Culture. Within two overlying house phases, a recessed area was recorded, which had been constructed using different sized pebbles. The arrangement and form of the feature clearly indicated anthropogenic origin and is understood as belonging to one of the house phases. Consequently, it is interpreted as a cellar. Several pits and post holes are additional features that were recorded at the site and indicate the presence of a fence structure with up to seven parallel courses. In this paper, we present radiocarbon dates from the features and an age model for the construction and use of the cellar as well as the fences. Moreover, the site Nygårdsvej 3 will be placed in its regional archaeological landscape. [ABSTRACT FROM AUTHOR]

Machine learning methods have advantages in predicting excavation-induced lateral wall displacements. Due to lack of sufficient field data, training data for prediction models were often derived from the results of numerical simulations, leading to poor prediction accuracy. Based on a specific quantity of data, a multivariate adaptive regression splines method (MARS) was introduced to predict lateral wall deflections caused by deep excavations in thick water-rich sands. Sensitivity of lateral wall deflections to affecting factors was analyzed. It is disclosed that dewatering mode has the most significant influence on lateral wall deflections, while the soil cohesion has the least influence. Using cross-validation analysis, weights were introduced to modify the MARS method to optimize the prediction model. Comparison of the predicted and measured deflections shows that the prediction based on the modified multivariate adaptive regression splines method (MMARS) is more accurate than that based on the traditional MARS method. The prediction model established in this paper can help engineers make predictions for wall displacement, and the proposed methodology can also serve as a reference for researchers to develop prediction models. [ABSTRACT FROM AUTHOR]

Abstract Ground subsidence is one of geohazards, particularly in urban environment due to its negative impact to nearby buildings and civil infrastructures. This study investigates the amount and spatial distribution of ground subsidence in Incheon City, South Korea, where ground excavation was made. Interferometric Synthetic Aperture Radar (InSAR) was used to monitor surface deformation around the excavation site. The study analyzed subsidence during an excavation project using Sentinel-1b satellite data, and the InSAR results were compared with traditional leveling methods and field measurements. Notable subsidence during the early construction phase was identified, which demonstrates the effectiveness of InSAR in urban environment. The research contributes to understanding of the excavation-inducing ground subsidence due to the reclamation layer.

Group excavations are composed of several individual excavations adjacent to each other with simultaneous or successive construction sequences (CS), which are distinctive from individual excavation in terms of the performance of excavation. In this study, a hyper-scale 3D finite element model was established to investigate the deformation behavior of a diaphragm wall system retaining a deep and oversized group excavation (DOGE) in Shanghai soft clay deposits. The numerical model simulated the practical construction stages and sequences, and it was verified by a series of comparisons with field measurements. Based on the numerical model, the spatial effect of the performance of DOGE in the process of excavation stages was investigated in this study, which cannot be addressed by limited field measurements. Furthermore, the effects of partition walls and CS on the deformation control were discussed to provide practical suggestions for oversized and deep excavations. The results indicate that the employment of bi-partition walls to divide the oversized excavation into several small pits and mono-partition walls and cross walls to further divide the pits near the metro lines into smaller ones, was proved to have significant effectiveness in controlling the wall deflection and protecting the adjacent metro line. For the partition wall, the magnitude and direction of the wall deflection primarily depended on the initial excavation, while the influence of subsequent excavation activities proved insignificant. Thus, it should be noted that the effect of the initial excavation should be especially concentrated. The findings can help optimize similar DOGE engineering.

Grazing livestock in uplands was a widespread practice in late Medieval and early modern Europe, but there can be uncertainty about the date and function of archaeological sites associated with herding. This paper reviews fieldwork on such sites in northern and northwestern Europe and reports on the excavation of a hut and enclosure in the mountains of southwestern Ireland. The hut was found to have been built in the 16th or 17th centuries a.d. and was probably used to oversee dairy animals (likely cows). The enclosure was dated to the early 18th or early–mid-19th century a.d. and is more likely associated with goat milking. The excavations demonstrate that construction dates can be obtained for pastoral sites in uplands of northwestern Europe. Furthermore, with careful reading of features in the surrounding landscape and consideration of documentary and ethnographic evidence, fieldwork can help determine the nature of pastoral economies over time. [ABSTRACT FROM AUTHOR]

In order to more accurately predict the lateral deformation of retaining structures caused by foundation pit excavation, this paper adopts support the vector machine model, traditional artificial neural network model, and two kinds of recurrent neural network models considering temporal inputs to establish a prediction model for the maximum lateral deformation of retaining structures in different foundation pits, and for the same foundation pit under different working conditions. The results show that the artificial neural network can update and predict the deformation of the retaining structure in real time based on the measured data of the project, which is helpful for timely planning of the next construction process of the project. In the prediction of lateral deformation of retaining structures under different working conditions, the cyclic neural network model considering temporal inputs is better than the traditional artificial neural network model.

Abstract Geological disasters occur frequently in the Loess Plateau due to the joint fissures in the strata and human engineering activities. Against this background, the deformation and failure mode of the loess slope with the structural plane under excavation and the extension mechanism of the structural plane are analyzed and summarized. The results showed that: (1) Through the physical model test, the deformation failure mode of the slope is summarized as the tension-splitting, pressure-sliding shallow failure. The collapse failure process is defined as four stages: Compression deformation, creep deformation, slip deformation and slip failure. (2) Slope displacement is concentrated beneath the pressure plate, increasing linearly under load conditions but becoming nonlinear after excavation conditions. As the excavation angle rises, the displacement range along the structural plane gradually extends toward the slope toe. The displacement time-history curve shows three stages: The lifting load stage, the cumulating deformation stage, and the sliding failure stage. (3) The stress redistribution caused by excavation, prompting deformation and potential failure. As internal stress nears the soil strength limit, human-induced disturbances exacerbate stress redistribution, leading to accumulated stress. Finally released through deformation and cracking. Each excavation condition modifies the original loading transfer path, driving stress redistribution at the slope surface and at the structural plane’s tip. (4) The sudden drop in stress level and sudden rise of accumulated settlement are the characteristics of slope sliding failure. The position of the structural plane determines the position of the slope sliding surface. (5) According to the external characterization of the structural plane, the extension process of the structural plane can be defined as four stages: Initiation of crack extension, classification deformation, subsection extension and compression sealing. According to the extension of the structural plane, the spreading cracks of the slope’s internal structural plane are defined as two types: Fractured cracks and shear cracks.

This paper presents an automated tool for comparative estimates of earthmoving productivity, focusing on excavation operations. The developed system includes three modules (computational, data storage, operational) and a series of forms that estimate construction productivity for three types of equipment (excavator, loader, truck) based on fourteen estimation methodologies. To the authors’ best knowledge, it is the first research attempt at developing an automated tool based on the comparative evaluation of such a diverse set of estimation methodologies. All system components have been developed in a Microsoft (MS) environment, thus taking advantage of their user-friendly nature. A numerical example corroborated the tool’s validity. Future research may optimize the module integrated into the developed application to assist construction estimators in reaching informed decisions when deploying critical project resources.

The double‐row capsule grouting (DRCG) is an innovative technique which can restrain the horizontal and vertical tunnel deformations induced by excavation simultaneously. The real‐time and active control capacity of DRCG can overcome the shortcomings in invariance and inefficiency of the traditional protective approaches. However, the performance of DRCG and the prediction method of control effectiveness have not been investigated. A numerical analysis using the hardening soil model with small‐strain stiffness (HSS model) is conducted to investigate the influences of the relative buried depth and the grouting volume of capsule on the control effect of DRCG in relation to the restoration ratio of horizontal deformation (Rh), and restoration ratio of vertical deformation (Rv). A polynomial relationship between parameters and restoration ratio is observed. Furthermore, a dimensionless formula, developed from hypothetical cases, shows a high conformity between predicted and numerical results. It can accurately predict the control effectiveness of DRCG. [ABSTRACT FROM AUTHOR]

Investigations into the temporally evolving stress state below the base of excavations and underground structures are very scarce, in contrast to studies of horizontal earth pressures during the construction stage. Therefore in this work, the measured temporal response in terms of vertical and horizontal effective stresses and displacements below a tunnel slab at the base of an excavation located in a deep sensitive clay deposit is reported. In addition to the measured unloading response over time, the completeness of the site description and complementary measurements enables future benchmarking of numerical models at boundary and element level. Instrument clusters of earth pressure cells and piezometers were installed at three locations in one cross-section. The monitoring data allow the interpretation of effective stress paths and stress ratios, K = σ h ′ / σ v ′ , at soil element level covering the construction and the serviceability stages. The in situ stress ratios enable a unique comparison to prior laboratory studies of K during unloading. The data presented herein on the evolution of K corroborate, although approximately, previous studies at laboratory scale. Furthermore, at system level, the monitoring data reveal the intricate interplay between deformations resulting from excavation and pile driving. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiao Tong University (1006-2467) is the property of Journal of Shanghai Jiao Tong University Editorial Office 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.)

A highrise tower atop short columns in Nantong, China was threatened by excavation of a subway station nearby. Although an elaborate protection plan composed of isolation piles, artificial recharge and underpinning was executed throughout the excavations, the tower underwent unacceptable settlements and notable inclinations. In combination of field measurements and numerical simulations, this paper investigates the tower's responses to the adjacent excavations, examines the effects of adopted protection plans and explores potential effective protection plans. First, the responses of the tower and the effectiveness of the three implemented measures were examined, and the contributory factors triggering intolerable tower deformations were identified; then, the effects of primary protection parameters were quantified, including the length, stiffness and layout of isolation piles, the water level surrounding recharge wells after recharging and the depth and location of wells, and the length of underpinning piles. It reveals that the underpinning plan had the best protection effect, followed by isolation piles and recharging wells. Construction timing of protection measures and termination manners of recharging are two critical factors in restraining tower deformations. Moreover, underpinning the tower with 36-m long steel pipe piles solely before implementation of adjacent excavations could be another optimal protection scheme. [ABSTRACT FROM AUTHOR]

Translational rockslides caused by toe excavation are one of the commonly seen geohazards in mountainous regions due to line traffic construction. Quantifying their failure extension length (FEL) and travel distance is of significant interest as well as huge challenges in landslide hazard assessment. In this paper, a simple criterion is proposed for predicting these two factors based on the principles of rigid body limit equilibrium and kinetic energy theorem. Further, the proposed criterion is validated against the field observations and numerical results with a practical case of the Xinjianan landslide, a medium-sized translational rockslide that occurred in 2013 in Nanchuan District, Chongqing. The findings indicate that a tiny discrepancy can be found in FEL between the field observations and the proposed criteria, while this discrepancy could be considerable in travel distance between different methods. However, the relative discrepancies all fall within 20%, deemed acceptable. [ABSTRACT FROM AUTHOR]

Since Artificial ground Freezing (AGF) appeared in the 1880s in the mining sector in Europe, it has been used for various construction applications worldwide. In recent years, it has been increasingly popular in urban projects due to its versatility and applicability to complicated site conditions. So far, it has been used to stabilize substrata to nearly 1,000 m below the ground surface, which is considered not possible for many other ground improvement technologies. Due to the growth in field applications, the practice and theories related to AGF have become more mature in the most recent two decades. The improvement in understanding of this topic is a result of lessons that have been learned through numerous projects, as well as a variety of comprehensive studies that have been completed. This paper reviews the existing practice, the recent development on AGF and the challenges of AGF. [ABSTRACT FROM AUTHOR]

Copyright of Journal of History / Habaršy Tarihi Seriâsy is the property of Al-Farabi Kazakh National University 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.)

Copyright of Journal of History / Habaršy Tarihi Seriâsy is the property of Al-Farabi Kazakh National University 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.)

Large landslides can involve the multiple failures of regional slopes. To understand the effect of lateral thrust caused by the failure of one slope on its surroundings, the failures of two adjacent highway slopes in Guangdong Province, China, were investigated in detail. The interactive failure processes and landslide morphological characteristics of the two slopes were first analyzed based on the on-site investigation. Then, a plane mechanical model of a large-scale slope was established to evaluate the significant influence of the lateral thrust generated by the west slope acting on the east excavated slope. Furthermore, the extrusion effect of the west slope was modelled under the alternate excavation disturbance and rainfall by transferring the thrust forces onto the interface elements, and the induced failure mechanism and instability mode of the east slope under lateral thrust were reproduced numerically. The results show that the compression-shear failure occurred at the middle and rear slope bodies because of the lateral thrust, which led to the formation of a thrust landslide and the final instability of the east slope. [ABSTRACT FROM AUTHOR]

The article reports on the discovery of megalithic tombs in the Ahlen-Falkenberger Moor in Germany. As part of a research project, three passage graves were examined, in which well-preserved elements of the burial constructions were found. Various burial activities of the Funnel Beaker Culture could be identified and dated. The excavations and scientific analyses provide insights into the complex architecture and use, as well as the environmental development around the megalithic grave Wanna 1592. Various identifiable phases are presented, including the construction of the monument, the burial level and activities in the entrance area, human impacts in the surroundings, destruction and sealing of the chamber, disturbance of the outer stone packing, and the disappearance in the bog. The text describes archaeological finds and soil analyses at a burial mound in Wanna. Two deposits were found, one outside the chamber and one inside the chamber, which can be dated to the Late Bronze Age. Ceramic fragments and flint artifacts were also discovered. The soil analyses show that the burial mound was built on a Luvisol surface, which has transformed into a Podsol outside the mound. Micro-morphological analyses were also conducted, revealing further details about the soil development. The article describes the results of an investigation of megalithic graves in Ahlen-Falkenberg, Denmark. It is noted that the graves have similar construction features and fit into the regional distribution of passage graves. It is speculated that the graves were built in a continuous working process, with social aspects playing a role in the choice and construction of the megaliths. The graves were likely built within a short construction period, and the materials came from the immediate surroundings. The graves were used during the Early Neolithic period and later abandoned in the Late Neolithic period. In Schleswig-Holstein, the entrance of a dolmen was destroyed in the Late Neolithic period. With the continuous rise of the bog water level, Wanna 1591 and 1592 were situated in wet contexts at the end of the Neolithic period, and Wanna 1588 at the latest in the EBA. Human activities increasingly focused on the higher Ahlen Geests, which included landscape clearances. The last practices were carried out during the transition from the Bronze Age to the Iron Age in Wanna 1588, when pottery vessels were placed between two capstones. In conclusion, it can be said that the megalithic landscape of Ahlen-Falkenberg has been well-preserved thanks to peat growth over the past thousands of years, providing insights into the original building elements and techniques, as well as burial practices of the FBC megaliths in the Neolithic period. Further excavations are necessary to clarify open questions. [Extracted from the article]

A new grouting technique, double-row capsule grouting (DRCG), has been developed and implemented in practice. This grouting technique could effectively mitigate excavation-induced tunnel movement and ensure the serviceability of metro lines. However, its control mechanism and the factors that influence its performance are not fully understood. Based on a case history that utilized capsule grouting the precision of the numerical model is validated. Parametric studies are conducted to investigate the influence of the grouting location and volume on the tunnel deformation, bending moment, restoration ratio, and shear strain of the soil. In addition, a comprehensive comparison between the conventional grouting technique and DRCG is performed to illustrate the control mechanism of this innovative technique. The results could contribute to a better understanding of the factors that impact the performance of DRCG and an optimal application of DRCG, which facilitates its efficient implementation and further development in engineering. [ABSTRACT FROM AUTHOR]