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The undrained lateral capacity of a group of two side-by-side piles has been studied in uniform clay, but the effect of spatial variability in clay strength on lateral pile capacity remains unclear. This paper describes probabilistic ultimate lateral capacity for two circular piles in spatially variable undrained clay. An adaptive finite element limit analysis based on random field generation combined with Monte Carlo simulations is applied. The lateral capacity statistics of two-pile groups with different combinations of pile spacings and pile roughness are presented. It is found that the consideration of the random nature of clay strength leads to a significant decrease in the lateral pile capacity, especially at a pile spacing approximately equal to the pile diameter. The factor of safety required to attain a target probability of failure is provided as a function of pile spacing. The obtained results give guidance for the reliability-based design of laterally-loaded two-pile groups in spatially varied clay and can also be applicable for understanding the lateral translation of two interfering cables and pipelines deeply buried in random clay. [ABSTRACT FROM AUTHOR]

ABSTRACT: Background: Hemorrhoids a prevalent anorectal disorder, have gained rising attention due to their impact on public health and quality of life. Despite their significance, limited research has addressed their prevalence and associated risk factors in the Jazan Region, Saudi Arabia. Thus, this study was designed to determine the prevalence and risk factors of hemorrhoids in Jazan region, Saudi Arabia. Methods: This was a cross-sectional study conducted in the Jazan region, Saudi Arabia, from January to June 2023. Encompassing both urban and rural areas, the study focused on individuals aged 18 and above, excluding those with communication difficulties, mental illness, or severe conditions. Employing random sampling, a sample size of 420 was determined to ensure representation, and participants were selected using a systematic random sampling technique. The analysis was performed using R version 4.2.3. Results: The study included 475 participants, predominantly females (72.57%), aged 25 to 44 (53.38%), with higher education (82.28%) and Saudi nationality (98.31%). Prevalence of hemorrhoids was 13.29%, with 5.27% external, 2.53% internal, and 0.21% thrombosed hemorrhoids. Constipation (OR: 2.28, P = 0.001) and family history (OR: 4.77, P < 0.001) were significant risk factors. Complications were reported by 5.70%, including ulceration (1.05%) and severe bleeding (1.05%). Social norms hindered treatment seeking for 55.49%. While age correlated (P = 0.002 and P = 0.003) with increased odds of hemorrhoids, gender, marital status, nationality, education, employment, smoking, exercise, and fiber intake showed no significant associations. Conclusion: In conclusion, the study revealed a 13.2% prevalence of hemorrhoids mostly external underscoring the significance of factors such as constipation age group, fiber intake, and family history in increasing susceptibility. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effects of antislide piles and cohesion anisotropy on seismic displacements of three-dimensional (3D) layered slopes. A discrete mechanism generated by the point-to-point technique is employed as the deterministic model, and the particle swarm optimization algorithm is used to determine the least upper-bound solutions. By combining the pseudostatic approach and Newmark's method, the yield acceleration coefficients ky and earthquake-induced displacements of two-layer slopes are further analyzed in varying positions of strong/weak layers, ratios of layer strength, reinforcement locations of piles, and anisotropy coefficients of cohesion. The results indicate that for the seismic slopes (strength ratio Sr = 1.5), displacement can be reduced by an order of magnitude after pile reinforcement; considering the anisotropy results in higher safety evaluations, typically, there is generally about a 65% reduction in the seismic displacement of Sr = 1.5 slopes when coefficient kc decreases from 1 to 0.7; the optimal pile locations in anisotropic slopes may be further away from the slope toe; the presence of a strong layer at the bottom of the slope is more conducive to slope stability than in the top, but it also makes the slope stability more sensitive to changes in layer strength ratio; the destabilizing/stabilizing effect of the weak/strong layer at the slope bottom is most pronounced at low values of its proportion; switching the strong layer from the bottom to the top, the maximum values of ky experience a 25%–40% reduction, while this percentage would be magnified when calculating its impact on displacement. Moreover, different from single-layer slopes, layer heterogeneity may also result in nonuniqueness in the optimal pile locations. [ABSTRACT FROM AUTHOR]

Construction in the Far North requires taking into account weather conditions. Different conditions result in different soil subsidence. These circumstances require the use of a special type of foundation for a multistory building, i.e., a pile foundation. We have developed the computational method and software for determining the seismic resistance of buildings in the Far North, allowing one to vary and take into account the number of floors, entrances, ceiling heights, frequency of pile arrangement, length and thickness of piles elastic and strength characteristics of materials, the form of soil subsidence, soil type, profile and type of incident seismic waves. In the test calculations in this manuscript, we varied the number of floors and entrances, the type of seismic wave, soil elastic properties, the pile frequency and determined the pile strength for all these sets of problem statements depending on the form of soil subsidence. We use the computational method from the family of grid-characteristic methods on a system of nonconformal curvilinear and Cartesian computational grids. A feature of this computational method is the saving of computing resources due to the following factors. Where possible, we use Cartesian computational grids. To account for arbitrary soil subsidence, we use curvilinear structured computational grids that are conformal with adjacent Cartesian computational grids. In this case, two adjacent curvilinear grids are nonconformal to each other. But we construct them in such a way that it is possible to use linear interpolation, which also allows one to save computational resources. [ABSTRACT FROM AUTHOR]

The aim of the article is a proposal for the construction of pile foundations of a building by drilling, including a proposal for the use of basic materials and machinery. The proposal is for workers who are directly connected with the implementation, control, management and acceptance of work. The article defines rules, guidelines and procedures that aim to ensure safety, quality and correct implementation of these work processes. The proposal serves workers to minimize risks and ensure efficiency and safety of work. In this way, compliance with legal requirements is ensured and potential problems and accidents on the construction site are prevented. [ABSTRACT FROM AUTHOR]

This paper presents two case studies dealing with undesirable impacts of overburden drilling of casings for end-bearing piles to bedrock. Monitored pore-water pressures and ground settlements are used to document and assess the influence from rotary percussive drilling with "down-the-hole" (DTH) hammers. The studies show that drilling with high-pressure air-driven DTH hammers may cause considerable erosion and soil volume loss adjacent to the drill bit and along the casing, resulting in settlements of the surrounding ground. The risk of soil volume loss increases when the drilling is carried out in erodible soils such as silt and fine sands. The volume loss is found to be caused by a combined air-lift pump effect and a Venturi suction effect. Monitoring pore pressures in the vicinity of the drilling may be used to reduce soil volume loss and prevent damaging settlements. Results from drilling with water-driven DTH hammer showed significantly less ground settlements and influence on pore pressures compared to using an air-driven hammer. The study suggests that the drilling parameters flow rate and penetration rate, and the cross-sectional area of the pile casing can be combined in a non-dimensional methodology to assess the mass balance of drill cuttings when drilling with water flushing. A design framework is suggested to guide overburden drilling in urban settings to reduce potential impact on the surroundings. [ABSTRACT FROM AUTHOR]

This paper investigates the use of a protective pile row barrier to mitigate the risk due to a deep excavation in soft soils adjacent to an existing tunnel. The study includes two reduced-scale 1 g model tests with and without the barrier, along with monitoring data from a case history in Wuhan, the Huazhong Science and Technology Industrial Park basement; physical testing and numerical sensitivity study results are compared to the case history to evaluate the barrier efficiency. The monitoring data show successful excavation and basement construction within allowable displacement thresholds in the presence of the barrier. The entire tunnel settled and translated towards the excavation, although different types of ovalization of the tunnel cross-sections were recorded depending on their alignment to the excavation (centre and corners). Experimental results indicate that the pile row barrier can withstand a portion of the soil pressure on the diaphragm wall, leading to a substantial reduction in tunnel bending moments and displacements; in particular, experimental results showed a greater percentage reduction in settlements than horizontal movements of the existing tunnel. When a pile row barrier is constructed in proximity to the retaining wall, it can help to minimise the detrimental effects of the deep excavation on the existing tunnel, similar to twin retaining wall scenarios. [ABSTRACT FROM AUTHOR]

The use of alternative reinforcement material to enhance the performance of the pile capacity has gained increasing interest in recent years. This study seeks to probe the improvement of the ultimate pile capacity, reduction the deformation, and the financial results of using alternative reinforcement material such as glass fiber-reinforced polymers (GFRP), geosynthetics geogrids, as well as a combination of geosynthetics geogrids and a central steel bar. Axial load investigations were conducted on circular piles with 150 mm diameter and 1050 mm height. The experimental results revealed an improvement in the axial capacity of up to 25.4% and an enhancement in performance represented in ductility. Furthermore, financial and weight comparisons showed a decrease in the cost by up to 15%. Moreover, a nonlinear finite element (FE) study with Abaqus software was employed to standardize the numerical outcomes with the laboratory findings. The FE analysis was also verified with the previous studies. The 3D nonlinear finite element numerical model performed showed convergence with and without representing the surrounding soil of the pile; thus, confirming the adequacy of the experimental setup adopted. Finally, a suggested theoretical equation is developed to evaluate the change in pile axial load capacity based on the use of different reinforcement materials. The application of the proposed theoretical equation provides further insight into the governing equation involving different reinforcing materials. [ABSTRACT FROM AUTHOR]

The structural integrity of pile foundations is critical for the safety and longevity of buildings and infrastructure. Low strain impact testing is a widely used non-destructive method for assessing pile length and identifying significant defects; however, its sensitivity to minor flaws remains limited. This study aims to enhance the detection capabilities of low strain testing for minor defects by proposing an improved methodology. We conducted field tests on ten piles with small, artificially introduced flaws and complemented these tests with three-dimensional numerical simulations. Initial timedomain analyses of both field and simulated data, using low-frequency wave excitation, did not reveal distinct signal features indicative of defects. To address this limitation, we employed a set of hammers with varying weights and head materials for wave excitation, simulated with different input force pulse durations. We further applied Complex Continuous Wavelet Transform (CCWT) for time-frequency analysis of the acquired signals, which effectively identified minor defects through characteristic changes in wavelet coefficient phase angles at expected timestamps. The consistency of CCWT phase spectrum features across signals from different hammers, considering the varying sensitivities of wave excitations, facilitates the differentiation of genuine flaw-induced phase shifts from noise. The study's findings were integrated into an improved low strain pile integrity testing workflow, enhancing the method's accuracy in detecting minor flaws. [ABSTRACT FROM AUTHOR]

The integrated building-bridge structure system represents integrated railway stations in China and has emerged as a new structural approach in recent years. This paper presents a case study on large shaking table tests that explore various seismic responses of a pile group system based on the Kunming South Railway Station. The study focused on the dynamic characteristics of both the soil and the pile-superstructure interaction. Findings indicate that pile damage is concentrated on the side facing the direction of vibration, with the middle pile experiencing greater damage than the corner pile. Hysteresis is observed in the growth of the pore pressure ratio during soil liquefaction in saturated conditions. Both the bending moment and the ground pressure acting on the pile increase with the degree of liquefaction. The maximum pile bending moment occurs at the interface between liquefied and non-liquefied soil layers. During seismic events, the side piles facing the vibration direction experience increased seismic surcharge, while the central piles are subjected to lower loads due to the isolation effect of the side piles. [ABSTRACT FROM AUTHOR]

To consider the complex soil-structure interaction in a pile-slope system, it is necessary to analyze the performance of pile-slope systems based on a three-dimensional (3D) numerical model. Reliability analysis of a pile-slope system based on 3D numerical modeling is very challenging because it is computationally expensive and the performance function of the pile failure mode is only defined in the safe domain of soil stability. In this paper, an efficient hybrid response surface method is suggested to study the system reliability of pile-reinforced slopes, where the support vector machine and the Kriging model are used to approximate performance functions of soil failure and pile failure, respectively. The versatility of the suggested method is illustrated in detail with an example. For the example examined in this paper, it is found that the pile failure can significantly contribute to system failure, and the reinforcement ratio can effectively reduce the probability of pile failure. There exists a critical reinforcement ratio beyond which the system failure probability is not sensitive to the reinforcement ratio. The pile spacing affects both the probabilities of soil failure and pile failure of the pile-reinforced slope. There exists an optimal location and an optimal length for the stabilizing piles.

Cyclic loads generated by environmental factors, such as winds, waves, and trains, will likely lead to performance degradation in pile foundations, resulting in issues like permanent displacement accumulation and bearing capacity attenuation. This paper presents a semi-analytical solution for predicting the axial cyclic behavior of piles in sands. The solution relies on two enhanced nonlinear load-transfer models considering stress-strain hysteresis and cyclic degradation in the pile-soil interaction. Model parameters are calibrated through cyclic shear tests of the sand-steel interface and laboratory geotechnical testing of sands. A novel aspect involves the meticulous formulation of the shaft load-transfer function using an interface constitutive model, which inherently inherits the interface model's advantages, such as capturing hysteresis, hardening, degradation, and particle breakage. The semi-analytical solution is computed numerically using the matrix displacement method, and the calculated values are validated through model tests performed on non-displacement and displacement piles in sands. The results demonstrate that the predicted values show excellent agreement with the measured values for both the static and cyclic responses of piles in sands. The displacement pile response, including factors such as bearing capacity, mobilized shaft resistance, and convergence rate of permanent settlement, exhibit improvements compared to non-displacement piles attributed to the soil squeezing effect. This methodology presents an innovative analytical framework, allowing for integrating cyclic interface models into the theoretical investigation of pile responses.

This paper proposes a practical approach for data-efficient metamodeling and real-time modeling of laterally loaded monopiles using physics-informed multifidelity data fusion. The proposed approach fuses information from one-dimensional (1D) beam-column model analysis, three-dimensional (3D) finite element analysis, and field measurements (in order of increasing fidelity) for enhanced accuracy. It uses an interpretable scale factor–based data fusion architecture within a deep learning framework and incorporates physics-based constraints for robust predictions with limited data. The proposed approach is demonstrated for modeling monopile lateral load–displacement behavior using data from a real-world case study. Results show that the approach provides significantly more accurate predictions compared to a single-fidelity metamodel and a widely used multifidelity data fusion model. The model's interpretability and data efficiency make it suitable for practical applications. [ABSTRACT FROM AUTHOR]

In an effort to investigate and quantify the patterns of local scour, researchers embarked on an in-depth study using a systematic experimental approach. The research focused on the effects of local scour around a set of four piles, each subjected to different hydromechanical conditions. In particular, this study aimed to determine how different attack angles—the angles at which the water flow impinges on the piles, and gap ratios—the ratios of the spacing between the piles to their diameters, influence the extent and nature of scour. A comprehensive series of 35 carefully designed experiments were orchestrated, each designed to dissect the nuances in how the gap ratio and attack angle might contribute to changes in the local scour observed at the base of pile groups. During these experimental trials, a wealth of local scour data were collected to support the analysis. These data included precise topographic profiles of the sediment bed around the pile groups, as well as detailed scour time histories showing the evolution of scour at strategic feature points throughout the test procedure. The analysis of the experimental data provided interesting insights. The study revealed that the interplay between the gap ratio and the attack angle had a pronounced influence on the scouring dynamics of the pile groups. One of the key observations was that the initial phases of scour, particularly within the first hour of water flow exposure, were characterized by a sharp increase in the scour depth occurring immediately in front of the piles. After this initial rapid development, the scour depth transitioned to a more gradual change rate. In contrast, the scour topography around the piles continuously evolved. This suggests that sediment displacement and the associated sculpting of the seabed around pile foundations are sustained and progressive processes, altering the underwater landscape over time. The results of this empirical investigation have significant implications for the design and construction of offshore multi-pile foundations, providing a critical reference for engineers and designers to estimate the expected scour depth around such structures, which is an integral part of decisions regarding foundation design, selection of structural materials, and implementation of scour protection measures. [ABSTRACT FROM AUTHOR]

This research adopts emerging machine learning techniques to tackle the soil–structure interaction analysis problems of laterally loaded piles through physics-informed neural networks (PINNs), which employs prior physical information in the form of partial differential equations during the model training, eliminating the tremendous data requirement in the traditional data-driven machine learning methods. The formulations to describe the problem are discussed, and the corresponding governing equations are derived. A PINN framework, including neural networks architecture and loss functions, is developed for the machine learning-based solution and elaborated with details. The corresponding model training process is presented, based on which the surrogate model construction and back analysis implementation are introduced to demonstrate the effectiveness and flexibility of the proposed method. This method has been demonstrated for its accuracy via several examples with benchmark solutions from the existing well-developed methods. Finally, a case study of the uncertainty evaluation of a laterally loaded pile is conducted to illustrate its high computational efficiency and advantages in potential engineering applications. [ABSTRACT FROM AUTHOR]

Several research studies have been conducted to strengthen weak road layers, regardless of whether they are under construction or constructed, and require maintenance using substrates filled with different materials, which have proven effective in increasing the strength of these layers. In this study, the objective of the work is to identify the maximum and minimum values of the coefficient of lateral soil pressure under various conditions when using reinforced and unreinforced piles filled with sand or granite grains and the extent of their contribution to strengthening road layers. An experiment was conducted using a box filled with soil, piles filled with sand grains or granite grains. It’s confirmed that there is a difference between the coefficients of lateral soil pressure when the piles are unreinforced or reinforced by dividing the sample into 2,3,4,5,6 parts by arming. The study found that the maximum value of the coefficient of lateral soil pressure in the case of sand (1 mm) reinforced is 0.38, whereas the maximum value in the same case with no reinforcement is 0.29. The maximum value of the coefficient of lateral soil pressure in the case of granite grain (2 mm) reinforced is 0.27, whereas the maximum value in the same case without reinforcement is 0.17. Moreover, the maximum value of the lateral pressure coefficient in the case of gravel (3 mm) reinforced is 0.26, and the maximum value in the same case without reinforcement is 0.30.

Earthquake-induced soil liquefaction can cause soil settlement around piles, resulting in drag load and pile settlement after shaking stops. Estimating the axial load distribution and pile settlement is important for designing and evaluating the performance of axially loaded piles in liquefiable soils. Commonly used neutral plane solution methods model the liquefiable layer as an equivalent consolidating clay layer without considering the sequencing and pattern of excess pore pressure dissipation and soil settlement. Moreover, changes in the pile shaft and the tip resistance due to excess pore pressures are ignored. A TzQzLiq numerical model was developed using the existing TzLiq material and the new QzLiq material for modeling liquefaction-induced downdrag on piles. The model accounts for the change in the pile's shaft and tip capacity as free-field excess pore pressures develop or dissipate in soil. The developed numerical model was validated against data from a series of large centrifuge model tests, and the procedure for obtaining the necessary information and data from those is described. Additionally, a sensitivity study on TzLiq and QzLiq material properties was performed to study their effect on the developed drag load and pile settlement. Analysis results show that the proposed numerical model can reasonably predict the time histories of axial load distribution and settlement of axially loaded piles in liquefiable soils both during and postshaking.

The paper analyses the behavior of a rigid passive pile embedded in a soil profile consisting of a stable layer underlying an unstable layer subjected to a uniform soil displacement. Pile-soil interaction is considered by modeling the soil by a series of elastic–plastic springs along the pile shaft. The modulus of horizontal subgrade reaction is assumed to linearly increase with depth in the unstable layer and constant in the stable one. The ultimate soil resistance is assumed increasing with depth in both layers. The results of analysis are presented in dimensionless form in terms of shear force developed at the slip surface as a function of the pile embedment into the stable layer and the distribution of soil characteristics over depth. The method allows capturing pile response not only at the soil ultimate state but also at the intermediate states. Specifically, the governing equations for the elastic, elastic–plastic and plastic cases are discussed and, whenever possible, a set of closed-form expressions is provided to estimate the maximum bending moment along the shaft and the pile head deflection, so that for an assigned value of the required stabilizing force both ultimate and serviceability limit state of the pile can be checked. A numerical example is given to illustrate the application of the proposed procedure. [ABSTRACT FROM AUTHOR]

The advantages of the FCAW-S technology when making circumferential welded joints of pipes with a diameter of up to 2520 mm are indicated. The rational shape of edges prepared for welding pipes with a wall thicknesses of up to 40 mm is proposed. It is shown that it is possible to construct assembly and welding areas (jigs) for site assembly of products at extremely low temperatures using exclusively domestic main equipment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) 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.)

This study addresses the problem of selecting an equivalent material for soil testing using piles on a large-scale experimental setup. The approach involved conducting model tests in a metallic tank with specific dimensions, allowing for a 1:25 scale. Fine and medium-grained sand was used as the equivalent soil material. The main criterion for sand selection was its similarity to medium-sized sand (0.25-0.50 mm). To ensure test reproducibility, only one sand fraction corresponding to the medium size was used. The results revealed that the chosen sand composition (Type 1) exhibited optimal homogeneity and particle size distribution. For modeling equivalent clay, Type 4 fine sand with 4% oil content was found to be the most suitable, demonstrating increased shear strength. The study concludes that the methods used effectively evaluate the load-bearing capacity of foundation piles, providing insights for optimizing designs for enhanced stability in diverse soil conditions. This approach paves the way for developing sustainable and ecologically efficient engineering structures in varying soil environments. [ABSTRACT FROM AUTHOR]

Physics‐informed neural networks (PINN) is an emerging machine learning technique and has been applied in different areas successfully. To benefit pile analysis from this innovative technique, this paper addresses several problems that arise when extending PINN to the large deflection analysis of slender piles accounting for nonlinear Soil‐Structure Interaction (SSI). The governing equations for the structural behavior of piles, considering geometric nonlinearity, are elaborated at first, based on which a PINN framework is constructed correspondingly with a model training process. A series of normalization factors are introduced to the loss function to enhance model training stability. Additionally, a regression‐based soil resistance estimation is developed to prevent non‐convergence and instability that may occur during the model training when encountering non‐differentiable SSI. Extensive examples are provided to validate the robustness and accuracy of the proposed analysis method for piles under complex geological conditions. Furthermore, several case studies are conducted, revealing the necessity of appropriate loss normalization and the effectiveness of regression‐based estimation for reflecting non‐differentiable functions in the PINN study. [ABSTRACT FROM AUTHOR]

In any high-rise building construction based on piles, it is essential to correctly evaluate their response when subject to high loads to avoid oversizing and consequently high costs. This work falls within the framework of the FONDASILEX project, which studies the behaviour of the pile foundations and the soil within the 'Silex2' tower project built in the Part-Dieu district in Lyon, France. This paper presents the geotechnical instrumentation executed for the foundations and the soil to enable the real-time monitoring of their behaviour. It details its conception, execution and limits. Five different types of electrical and unconventional sensors, including the fibre optic technique, which is based on reflectometry by Rayleigh scattering, were employed. This instrumentation allowed us to measure the soil settlement, the applied load at the head of the pile and the induced deformation in the concrete. The obtained measurements showed good agreement between all the sensors and were compatible with the real applied load. The results of this monitoring completed with an additional specific study to characterize the soil will be used in a future study to calibrate numerical models simulating the behaviour of high-rise building foundations. [ABSTRACT FROM AUTHOR]

This paper investigates the response of finned piles in sand subjected to static lateral load through laboratory tests and full-scale field tests. Firstly, model tests were carried out on free headed single piles of different shaft diameters with and without fins in sand to explore the performance of the piles under lateral loading. The results obtained from monotonic loading tests on three series of piles of three different combination of fins and pile shaft diameters were presented. The effect of fins on improving the stiffness and ultimate lateral capacity of the piles was discussed. An equivalent diameter was proposed for a finned pile, which enabled the experimental results to be back calculated using an available elasto-plastic solution for laterally loaded piles in sand. Secondly, field tests were conducted on laterally loaded Starfin screw piles in loose to medium dense sand. The proposed approach was then used for the analysis of the measured response of Starfin screw piles and further validated against measured test results from fully instrumented finned piles in overconsolidated dense sand. The results show that the proposed equivalent diameter and approach for the analysis of finned piles provided the most satisfactory match to the measured data, ranging from the initial elastic state to the ultimate limit state. [ABSTRACT FROM AUTHOR]

Earthquake-induced soil liquefaction can cause settlement around piles, which can translate to negative skin friction and the development of drag load and settlement of the piles. A series of centrifuge model tests were performed to assess liquefaction-induced downdrag and understand the interplay and effects of (1) pile embedment and pile-head load, (2) excess pore pressure generation and dissipation, and (3) reconsolidation and ground settlement on pile response during and postshaking. The model included a layered soil profile (clay, liquefiable sand, and dense sand) with two 635-mm-diameter instrumented piles. One pile was placed with its tip at the bottom of the liquefiable deposit; the other pile was embedded five diameters into the dense sand layer. The model was shaken with multiple earthquake motions with their peak horizontal accelerations ranging from 0.025 to 0.4 g. For each shaking event, the drag load on the piles first decreased during shaking and then increased during reconsolidation, exceeding its preshaking value. With multiple shaking events, the net drag load on the piles increased. The maximum observed drag load was found equal to the drained interface shear strength calculated from the interface friction angle of δ=30° and a lateral stress coefficient of K=1. Larger drag loads and smaller settlements were observed for the pile embedded deep in the dense sand layer. Most of the pile settlements occurred during shaking; postshaking pile settlement was less than 2% of the pile's diameter. The mechanisms behind the development of liquefaction-induced drag load on piles and settlements are described. Select ramifications concerning the design of piles in liquefiable soils are also described.

It is nowadays recognized that the load-transfer P-Y curves methods offer a powerful framework of analysis of the pile response under lateral loading. The aim of this paper is to present a new formulation the P-Y curves to analyze the response of a single pile embedded in clayey soil, on the basis of the CPT test data. The methodology of work consists of analyzing 8 lateral loading tests on fully instrumented piles driven into a homogeneous saturated clayey soil. The P-Y curves were formulated by the PARECT (parabola-rectangle) function, and successful correlation of their parameters, namely the lateral reaction modulus and the lateral soil resistance, with the cone resistance as well as with the lateral pile/soil stiffness ratio was made. After a comparison with the existing P-Y curves methods, a methodology of analysis by the proposed P-Y curves for piles in normally consolidated to slightly over-consolidated clays was suggested. Moreover, a pile classification according to the pile/soil stiffness ratio was suggested, and the concept of the critical deflection corresponding to the threshold of domain of large deflections of piles was introduced. Validation process was launched by applying this methodology to a centrifuged scale model of a single bored pipe pile in a saturated slightly over consolidated clay. Direct comparison of the load-deflection curves showed an excellent prediction of the small deflections up to about 2% of the pile diameter. Beyond this value, the boundary conditions at the pile tip have an influence on the results, but showed a relatively pessimistic prediction.

The effect of geocell-reinforced cushion on load distribution and settlement reduction in unconnected piled raft foundations was investigated. Modeling and analysis of various scenarios were carried out using Abaqus software. In this research, a total of nine models, including one connected, three unconnected and unreinforced, and five unconnected and reinforced with geocell, were analyzed. Cushions with thicknesses half of, equal to, and twice that of the foundation were used. The results have shown that optimal outcomes in terms of load distribution efficiency and settlement reduction are achieved when the cushion's stiffness is set at half that of the foundation. The obtained results demonstrate the positive effect of geocell reinforcement in enhancing the performance of unconnected piled raft foundations. The introduction of geocells into the models increases soil stiffness and pile load ratio, consequently enhancing the load-bearing capacity of the piled raft foundation compared to the unreinforced models. The study's findings pave the way for a more effective use of geocells in civil engineering applications, particularly in scenarios demanding high load-bearing capacity and minimal foundation settlement.

This paper presents a novel analytical formulation to study the impact of shear deformations on beam-columns and piles by means of the Timoshenko-Engesser’s and Timoshenko-Haringx’s theories. The proposed solution enables the analysis of lateral deformation or buckling, while considering the effect of shear deformations. It offers the flexibility to i) incorporate different boundary conditions at the ends of the element (e.g., semi-rigid connections and lateral transverse springs) and ii) consider an inhomogeneous elastic foundation. When certain variables are disregarded, the proposed GDE can capture particular cases of GDEs found in the literature for beam-columns and piles. Examples are provided to demonstrate the simplicity and practicality of the proposed method, and its accuracy is validated against available analytical or numerical methods. The influence of the shear effects, as computed from Engesser’s and Haringx’s methods, on the lateral and buckling responses of beam-column and pile elements is discussed.

The seismic design of pile foundations mainly relies on analyzing the seismic response of layered, liquefiable locations. Two design scenarios are taken into consideration from the case histories; the first is how pile foundations react to the stresses and lateral displacements brought on by the lateral dispersion of liquefied soil. The second is how to piles reaction to seismic activity that occurs with the development of high pore water pressures. The PLAXIS 3D software is utilized in this research with a non-linear soil constitutive model (hypoplastic model) for both dry and saturated loose sandy soils under the impact of two earthquakes and the motion of different features to give a complete understanding of the dynamic piled foundation response. The findings from this study show that the site profile, pile diameter, pile length, and excitation of ground motion significantly affect the dynamic response of the layered liquefied site. So, in the saturated case, the increase in the piles length to (L/D = 55) in comparison to the original length (L/D = 35) decreased the peak acceleration at the raft foundation by about (24.4 and 41.9) % under the effect of Kobe and Upland earthquake motion, respectively, while in the dry case, the reduction in peak acceleration was about (22.8 and 40.9) % under the effect of Kobe and Upland earthquake motion, respectively.

The most widely used analysis method for the laterally loaded pile problem is the Winkler spring approach. Although researchers have proposed nonlinear formulations for the p-y curves, the contribution of the soil nonlinearity has not been thoroughly studied. The main drawback of the current approach is the use of a single stiffness in the p-y formulation. This study investigates the laterally loaded pile problem by employing the pressure-dependent hardening soil model with small-strain stiffness (HS-Small Model), where the degree of soil nonlinearity is better integrated. The parametric analyses are performed on the verified model for various pile and soil properties. A new p-y model is proposed for pile behaviour under monotonic loading based on the numerical analysis results. The model includes the initial stiffness, ultimate soil resistance, and degree of nonlinearity parameters. The validity of the proposed model is demonstrated by simulating a centrifuge and two field tests from the literature. The proposed model accurately accounts for soil nonlinearity and significantly improves the estimation of lateral displacements.

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering 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.)

Major structures like offshore platforms, wind turbines, transport infrastructure, tall buildings, etc., resting on soft compressible clays, are often supported by pile foundations. Apart from usual vertical loading (dead load, live load, etc.), these piles are subjected to significant cyclic loads arising from actions of waves, ship impacts, winds or moving vehicles. Under such circumstances, the lateral mode of cyclic loading is predominant and affects the overall foundation stability. Such repetitive loading leads to stress reversal in adjacent soft clay initiating progressive degradation in soil strength and stiffness, deteriorating the pile capacity with unacceptable displacements. Although several past studies investigated the response of single pile under lateral cyclic loading, a detailed investigation on pile group in clay subjected to cyclic lateral loading, which is of immense practical interest to field engineers, is yet to be carried out. In this paper, in-depth study has been carried out by developing a three-dimensional dynamic finite element model. Comparison of the computed results with available test data validates the numerical model. Extensive parametric studies with field data indicate that both the axial and lateral pile capacities and displacements have been significantly influenced by the cyclic loading parameters. Relevant design curves are also constructed. [ABSTRACT FROM AUTHOR]

In 2021, during underwater archaeological surveys in the lake district of eastern Lithuania, a new settlement was discovered on an island in Lake Bėlis (Švenčionys district). According to 14C AMS data, it dates to the 8th-4th centuries BC. The newly discovered Lake Bėlis island settlement stands out due to its size -- it is a very small area of land -- and because of its well-preserved structures and functional zones. A distinctive feature of this settlement is the wooden structures -- piles -- found on the underwater slopes around the island, extending along its entire perimeter. Additionally, the research was conducted in an archaeological layer situated in a wetland environment rich in preserved organic material. This article discusses the research on the island of Lake Bėlis, conducted from 2021 to 2023. In recent years, research in Lithuania has produced a significant amount of original material (new sites or reanalysis of known data) from the Late Bronze Age to the Pre-Roman Iron Age. The evidence analysed in this article suggests that in this period, besides common settlement types -- hillforts, unenclosed settlements and lake dwellings -- there were also settlements located on natural lake islands. [ABSTRACT FROM AUTHOR]

Copyright of Firat University Journal of Experimental & Computational Engineering (FUJECE) is the property of Firat University Journal of Experimental & Computational Engineering (FUJECE) 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.)

Pile foundations are widely used to transfer structural loads to hard soil layers with high bearing capacity. During the design work, it is often necessary to combine the structural solutions of the foundations with the properties of the subsiding soils at the construction site. This article deals with pile foundations and their bearing capacity dependences on embedment depth, soil properties and pile diameter. [ABSTRACT FROM AUTHOR]

Specific features of the manufacture and delivery of piles and welded pipe sheet piling (WPSP) for the construction of seaports in the Arctic zone are described. It is shown that it is necessary to update the GOST R 52664–2010 standard by expanding the range of standard sizes of manufactured WPSP to include a diameter of 2520 mm and to harmonize the requirements of GOST R 52664–2010 and GOST 33228–2015. [ABSTRACT FROM AUTHOR]

This work presents the results of work on import substitution of anticorrosive protective coatings of pile products of hydraulic structures for the categories of corrosion aggressiveness CX and immersion Im4. [ABSTRACT FROM AUTHOR]