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In this study, the dynamic response and damage mode of a pile-geogrid composite reinforced high-speed railway subgrade under seismic action were investigated based on a unidirectional shaking table test. Various seismic waves were applied to the subgrade, allowing for an analysis of acceleration, dynamic soil pressure, displacement, and strain responses. The displacement field of the subgrade was visualized using particle image velocimetry (PIV). The study shows that changes in peak ground acceleration (PGA) amplification factors become evident with height due to the presence of geogrid layers. The increase in peak ground motion causes a redistribution of dynamic soil pressures inside the subgrade. The transverse and longitudinal ribs of the geogrids provide an "anchoring effect". The peak strain of the piles in the center is greater than that of the piles on the sides. The direction of soil particle displacement is closely related to the damage patterns observed in the subgrade. Damage begins to occur once the peak ground motion exceeds 0.4 g, characterized by collapse at the bottom of the subgrade. • PGA amplification factors became evident layering with height owing to the geogrids in layers. • The horizontal and longitudinal ribs of the geogrids provide a strong "anchoring effect". • The peak pile strain in the middle position of the subgrade will suddenly increase. • The direction of the soil particle displacement field has a strong correlation with the damage of the subgrade. [ABSTRACT FROM AUTHOR]

Polyurethane foam (P.U.) injection resin techniques have been widely used for slab crack repair, soil improvement, and structural crack repair over the past 20 years. In this study, numerical investigations were carried out to enhance the strength of both sand and clay soils via utilizing polyurethane foam as inclusion material. The investigation was conducted using 'GeoStudio (SLOPE/W) 2D' software to model 6 m high homogeneous slopes made of soft clay and medium sand with varying slope angles (25°, 30°, 35°) on same soil extended up to 9 m depth and with inclusion of polyurethane foam piles of varying diameter (0.5 m, 0.8 m), length (up to 10 m) and spacing (0.5 m, 1 m, 2 m) in the slope face. The numerical model was verified using experimental test results conducted by Hassona and Abdelnaeem (Physical and mechanical properties of polyurethane foam conditioned sand. MSc, Civil Engineering Department, Faculty of Engineering Minia University). The results revealed that, for slope angle, Ø = 30°, the factor of safety for clay soil increased when using polyurethane piles (diameter, 0.5 m and 10 m length) having spacing of two m, one m, half m, and when used as sheet piles, respectively. The factor of safety for clay soil increased significantly when using polyurethane piles (diameter, 0.8 m, and 10 m length) having spacing the same as before and as sheet piles having width of 0.5 and 0.8 m, respectively. Also, for medium dense sand soil, using polyurethane piles (diameter, 0.5 m and 10 m length) having spacing the same as before, and as sheet piles increased factor of safety much more than that for clay soil. In addition, for medium dense sand soil similar observation were noticed using polyurethane piles (diameter 0.8 m, and 10 m length) having spacing the same as before, and as sheet piles, respectively. In addition, the effects of slope angles also studied. [ABSTRACT FROM AUTHOR]

The batter rock-socketed pile (BRSP) groups have been gradually introduced in practice to support not only the vertical load caused by overlying infrastructures but also the horizontal loads caused by waves and wind. A series of laboratory model tests were conducted to investigate the bearing capacities of the BRSP groups installed with their batter piles ranging from 0° to 20° under combined vertical and horizontal loads. It is found that the vertical ultimate bearing capacities nonlinearly increase with the increase of the batter angle with its optimum batter angle of 10°. The normalized vertical loads and horizontal ultimate loads are nonlinearly related to their relationship in an ellipse function. The plumb rock-socketed pile groups develop primarily a pair of shear forces and secondary bending moments due to the clockwise rotation under the pure horizontal loads. The BRSP group may fail due to the pile fracture near the pile cap in the form of the plastic hinge or compression failure at the base of the front pile. The corresponding load-displacement curves mostly have no peak or sudden downward trend. [ABSTRACT FROM AUTHOR]

The numerical simulation of boundary value problems involving a high number of pile-type structures, such as pile foundation systems of high-rise buildings, represents a standard task in computational geotechnics. Due to their ability to simplify the underlying pile modeling process and decrease the simulation runtime embedded beam formulations (EBFs) have attracted widespread interest from the geotechnical community. State-of-the art EBFs are typically equipped with nonlinear interface constitutive models to capture the soil–structure interaction behavior with reasonable accuracy. However, reliable information concerning the calibration of related parameters is limited, which decreases the confidence in the results obtained with EBFs. The present work addresses this research aspect for the first time, along with a theoretical discussion of inherent simplifications in the numerical description of the soil–structure contact associated with EBFs. The significance of selecting adequate embedded interface constitutive model parameters to ensure EBF predictions with high credibility is demonstrated by means of parametric studies. This has motivated the development of an automatic calibration software, leveraged by particle swarm optimization, that provides guidance in selecting suitable values. The effectiveness of the calibration software is confirmed by back-calculation of different pile problems with default and calibrated parameter sets. Likewise, the results provide insight into crucial factors driving the calibration framework, with a view to increasing its potential for take-up in engineering practice. Potential lines of research in the context of the automatic calibration software are explored throughout this work and may serve as valuable reference in future research. Practical Applications: The design of geotechnical problems involving a high number of pile-type structures, such as pile foundation systems of high-rise buildings or wind turbines, is routinely assisted by finite-element analyses. The computational expense of these simulations is significantly influenced by the pile modeling technique. Due to their exceptional ability to simplify the underlying modeling process and reduce the runtime to an acceptable limit, embedded beam formulations have therefore attracted widespread interest for geotechnical design tasks. As with all soil–structure interaction problems, it is essential in embedded beam formulations to accurately describe the interface behavior between the soil and the structure. This work presents the first attempt to highlight the relevance of this concern and visually describes relevant limitations resulting from an inadequate selection of interface constitutive model parameters. This observation has motivated the development of an automatic calibration software to increase the confidence in the parameter selection. The high potential of this software to increase the credibility of numerical predictions obtained with embedded beam formulations is demonstrated based on pile problems with different soil stratification layers, pile geometries, and pile arrangements. In all cases considered, the results confirm that the numerical fidelity could be significantly increased by employing calibrated parameter sets. [ABSTRACT FROM AUTHOR]

The design of large-scale pile foundation systems is routinely assisted by finite element simulations. To a large extent, both the modeling and the computational effort of such analyses are governed by the adopted pile modeling technique. The traditional approach to this problem fully resolves the pile and soil domain employing solid elements, resulting in considerable meshing constraints and high simulation runtimes that may be regarded as unbearable for many practical purposes. As an attractive alternative to circumvent these obstacles, embedded FE models have become increasingly popular in solving this modeling task, mainly due to their flexible meshing procedure and significantly enhanced runtime efficiency. In a preceding contribution, the authors have proposed an extended formulation that provides a rigorous framework to capture soilstructure interaction effects at the physical soil-pile contacts. As a key feature, the implemented combined soil-pile coupling scheme explicitly accounts for endpoint interaction. However, validation studies have been constrained to single pile analyses to date. The present work expands this validation scope to largescale boundary value problems involving multiple piles and investigates the model performance based on three different case studies. The results are compared to both, measurements and numerical benchmark solutions and provide exclusive insight into the numerical fidelity of the developed embedded FE model, with a view to increasing its potential for take-up in engineering practice. [ABSTRACT FROM AUTHOR]

The overall reinforcement of soft soil foundation has the disadvantages of large engineering quantity and high cost. When the pile foundation bears horizontal loads in the soil, the mechanical properties of the soil near the surface have a greater impact on it compared to the deep soil. Therefore, studying the influence of shallow soil reinforcement on the horizontal bearing capacity of pile foundations has important engineering significance. Studying the influence of shallow soft soil reinforcement around piles on the horizontal bearing performance of piles is of great significance for improving the economic efficiency of pile foundation reinforcement technology in soft soil areas. In this paper, seven pile-soil finite element models are established based on ABAQUS 2022 software to study the influence of shallow reinforcement on the horizontal bearing capacity of single pile. The models were established on the basis of a field test and its validity was verified. The influence of different reinforcement degrees on the horizontal bearing capacity of piles is analyzed by taking the reinforcement width and reinforcement depth as variables. The results indicate that shallow ground improvement significantly enhances the horizontal bearing capacity of the pile. The horizontal bearing capacity of the pile is increased by 83.0%, 104.3%, and 224.4%, respectively, corresponding to a reinforcement width of 2 times, 3 times, and 4 times the diameter of the pile, respectively. With the increase of the reinforcement width, the bending moment and deformation of the pile under the same horizontal load decrease significantly, while it has no significant effect on the location of the maximum bending moment of the pile. The bearing capacity of the pile foundation gradually increases with the increase of the reinforcement depth. Compared with the unreinforced situation, the horizontal bearing capacity of the pile body is increased by 224.4%, 361.3%, and 456.8%, respectively, corresponding to a reinforcement depth of 0.1 times, 0.2 times, and 0.3 times the pile length. As the reinforcement depth increases, the corresponding increase in bearing capacity does not increase linearly, but gradually decreases. This indicates that blindly carrying out deep soil reinforcement without comprehensive evaluation is not advisable. [ABSTRACT FROM AUTHOR]

Fang Wang,1,&ast; Chang Jiang,2– 4,&ast; Wenzhuo He,2– 4,&ast; Heping Li,1 Gui-Fang Guo,2– 4 Lixia Xu1 1Department of Oncology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong Province, People’s Republic of China; 2State Key Laboratory of Oncology in South China, The Sun Yat-Sen University Cancer Center Guangzhou, Guangzhou, Guangdong Province, People’s Republic of China; 3Collaborative Innovation Center for Cancer Medicine, The Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong Province, People’s Republic of China; 4VIP Department, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong Province, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Lixia Xu, Department of Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong Province, People’s Republic of China, Email xulixia@mail.sysu.edu.cn Gui-Fang Guo, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, VIP Department, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong Province, People’s Republic of China, Email guogf@sysucc.org.cnPurpose: The response of patients with biliary tract carcinoma (BTC) to immunotherapy varies widely, and there is an urgent need for biological indicators. The predictive value of inflammation based score (IBS) for the efficacy of immunotherapy in patients with BTC remains unclear, as the evidence is inconsistent. This study aimed to comprehensively examine the predictive value of IBS in peripheral blood on the survival of BTC patients receiving immunotherapy.Patients and Methods: We retrospectively assessed 118 patients with advanced BTC who received anti-PD-1 therapy in the first or second line in two medical centers. The Kaplan-Meier, time-dependent ROC, and Harrell’s concordance index (C-index) were applied to analyze the predictive value of 13 reported peripheral blood IBS.Results: All 13 IBS were identified as significant prognostic factors for OS in univariate analysis. Pan-immune-inflammation value (PIV) (p=0.005), PILE (composed of PIV, lactate dehydrogenase and Eastern Cooperative Oncology Group performance status) (p=0.033), neutrophil-to-lymphocyte ratio (NLR) (p=0.003), platelet-to-lymphocyte ratio (PLR) (p< 0.001), lymphocyte-to-monocyte ratio (LMR) (p=0.006), systemic immune inflammation index (SII) (p=0.039), CRP-to-albumin ratio (CAR) (p=0.025), and Albumin-NLR (p=0.008) were identified as independent prognostic factors for OS in multivariate analysis. PIV and PILE scores were superior to other scores, according to time-dependent ROC curves, and their superiority became more pronounced after the 12-month time point. C-index analysis showed PIV (C-index 0.62, 95% CI: 0.55, 0.68) and PILE (C-index 0.62, 95% CI: 0.55, 0.70), both superior to other IBS.Conclusion: PIV and PILE scores are independent predictors of OS in patients with BTC after immunotherapy and are superior to other IBS. PIV and PILE may be able to help screen out patients with advanced BTC who are less likely to benefit from anti-PD-1 monotherapy. Due to the retrospective nature of this analysis, the predictive value of PIV and PILE require validation in further prospective studies.Keywords: biliary tract carcinoma, anti-PD-1 therapy, inflammation-based scores, pan-Immune-Inflammation Value, PILE

This paper presents a novel approach to mitigating Newtonian noise (NN) in laser interferometer gravitational wave observatory (LIGO) on Earth's surface. The proposed method offers an unprecedented means to enhance the sensitivity of terrestrial gravitational wave (GW) detectors in the low-frequency range by leveraging seismic metamaterial-based unit cell analysis. The key concept involves deploying metamaterial-based piles in the ground surrounding the primary test masses of a gravitational wave detector. This strategic placement aims to reduce the coupling of Rayleigh waves, contributing to seismic disturbances affecting test mass displacement. The discussion delves into the design considerations of cylindrical pile shapes, emphasizing their effectiveness in minimizing seismic interference. By harnessing metamaterial principles and carefully engineering the configuration of these piles, the proposed method holds promise for substantially improving the performance of terrestrial GW detectors, particularly in mitigating low-frequency noise sources. The study utilized finite-element simulations to investigate how the parameters of the metastructure and the frequency of seismic excitation impact the reduction of NN. These simulations reveal a frequency-dependent suppression of NN for the advanced LIGO configuration, particularly affecting sensitivity in the 9–15 Hz frequency band. Moreover, the analysis extends to quantifying the reduction of gravity gradient noise through both time and frequency domain analyses. An analytical expression is provided to estimate the density perturbations induced by Rayleigh waves in the medium. This approach demonstrates a favorable advantage-to-cost ratio and enhanced practicality for future infrastructures. By applying these findings, there is potential to significantly improve the sensitivity of current and future ground-based gravitational wave detectors. Additionally, the metamaterials approach holds promise for safeguarding critical infrastructure such as nuclear power plants, particularly in regions where the estimation of hazards is challenging. This indicates broader applications beyond gravitational wave detection, highlighting the versatility and importance of metamaterials in various fields. [ABSTRACT FROM AUTHOR]

The model presented in this paper was prepared to determine the pile toe resistance mobilization mechanism. Due to the fact, that skin resistance of piles was widely analyzed by the Authors in previous papers [1,2] which were based on both field and laboratory test results, currently the main focus is to describe the mobilization of pile toe resistance. The physical experimental model consists of a chamber measuring 2.2 m, 2.4 m and 6.0 m in width, length, and height, respectively, filled with cohesionless soil. The model has a hydraulic cylinder to apply force at the pile head and equipment to measure pile settlement with force mobilized at the pile base. The purpose of this research was to verify previously formulated methods referring to the M–K curves. Furthermore, the research allowed us to examine if the relationship between pile toe resistance and force applied at the pile head is linear. As a result of the tests, it was confirmed that for purposes of practical engineering calculations, the resistance of the pile toe can be described regarding the load, which is applied at the pile head. The description of this relationship is presented with M–K curve parameters.

The article provides an analysis of the results and causes of increased settlements of cement plant structures and the negative impact of leveling embankments, atmospheric precipitation and surface water on settlements of structures. Many design firms for the design of civil, industrial and infrastructure construction projects, often ignoring the requirements of the relevant building codes and regulations, design buildings and structures only based on the bearing capacity of soils and the deformation characteristics of the soils of the foundation of buildings and structures are not taken into account. In some cases, when designing buildings and structures, even for two limit states, the weight of the embankment is not taken into account, which will lead to additional compression of the underlying soils. In addition, when designing foundations and bases of a structure, the physical and mechanical properties are not taken into account, including the composition of the soils of the planning embankment, which often create additional negative impacts on the reliability of the structure during the operation of construction projects. One example of the noted processes is the experience of designing and constructing a cement plant in the administrative territory of the Gazakh region of the Republic of Azerbaijan. [ABSTRACT FROM AUTHOR]

Most of the existing methods of pile settlement calculation, including normative methods, do not fully take into account the processes occurring in the soil when loads are transferred to them and the changes in the properties of the contact zone soils. This leads to underutilisation of the bearing capacity of the soil, and the calculated settlement value may differ several times from the real values. In this paper, a graph-analytical solution to the problem of interaction of a single pile with a three-layer soil foundation is proposed to determine the settlement, taking into account the complex nature of the pile operation and the processes occurring in the soil when loads are transferred to them. The proposed method allows to use the non-linear behaviour of the soil on the lateral surface and under the tip of the pile, the possibility of its detachment and slippage after reaching the ultimate strength of the soil, changes in the properties of the contact zone soils, and the load distribution on the pile between its lateral surface and the tip. To verify the proposed graph-analytical solution, a comparative analysis was performed with the numerical method in the Plaxis 2d software (version 21.00.01.7) and with the results of static tests of piles at the construction site. To determine the strength reduction factor at the contact of soils with concrete, laboratory tests were carried out on a direct shear apparatus. Based on the results of the performed calculations, graphs of the dependence of settlements on loads were plotted, conclusions were drawn about the possibility of using the graph-analytical method, and prospects for further development and improvement of the graph-analytical method were proposed. [ABSTRACT FROM AUTHOR]

Piled rafts and pile groups are the common types of deep foundations for tall buildings subjected to combined loading. Their complex behavior made their design and analysis very complex and sometimes uneconomical. This paper explores the distribution of lateral load on piles within a piled raft and pile group under a constant vertical load. The study utilized experiments with small-scale models of piles and rafts to observe the behavior. The response of each pile was recorded and analyzed with respect to lateral displacement. The results indicated that in the case of piled rafts under lateral load, the rear piles are resisting more load than the front piles, unlike in pile groups where front piles carry more load than rear piles. This behavior continued until the number of piles reaches nine, thereafter the load-carrying behavior shifted, and front piles began to carry more lateral load. The reason behind this shift is that as the number of piles increases, the raft contact pressure decreases and subsequently decreases the stiffness of soil below raft and hence the piled raft starts behaving as a pile group, where front piles carry more lateral load. [ABSTRACT FROM AUTHOR]

In view of the influence of the inclination and variable section on the pile stability and bearing capacity, this paper introduces particle image velocimetry (PIV) technology, and designs a transparent soil visualization model test. The experimental results show that, when the pile has a variable cross-section and inclination angle, the friction resistance on both sides of the pile increases. The vertical-load-carrying capacity of the 2% and 4% inclined piles with a variable cross-section is greater than that of the piles with inclinations greater than 8%. For model piles with the degrees of inclination of 2% and 4%, the variable-section inclined piles with diameters of 17 mm and 15 mm show significantly less settlement than the equal-section inclined piles. For the model pile with an inclination of 8%, the settlement of the inclined piles with a variable cross-section diameter of 17 mm is slightly smaller than that of the equal cross-section inclined piles. The change in variable cross-section and inclination angle has a large effect on the soil displacement around the pile, and the conclusions of this paper can provide guidance for the engineering application of variable cross-section piles. [ABSTRACT FROM AUTHOR]

The model presented in this paper was prepared to determine the pile toe resistance mobilization mechanism. Due to the fact, that skin resistance of piles was widely analyzed by the Authors in previous papers [1,2] which were based on both field and laboratory test results, currently the main focus is to describe the mobilization of pile toe resistance. The physical experimental model consists of a chamber measuring 2.2 m, 2.4 m and 6.0 m in width, length, and height, respectively, filled with cohesionless soil. The model has a hydraulic cylinder to apply force at the pile head and equipment to measure pile settlement with force mobilized at the pile base. The purpose of this research was to verify previously formulated methods referring to the M–K curves. Furthermore, the research allowed us to examine if the relationship between pile toe resistance and force applied at the pile head is linear. As a result of the tests, it was confirmed that for purposes of practical engineering calculations, the resistance of the pile toe can be described regarding the load, which is applied at the pile head. The description of this relationship is presented with M–K curve parameters. [ABSTRACT FROM AUTHOR]

The paper presents two applications (software packages) in which the load-transfer method is used for axially loaded Kelly drilled bored piles and displacement ductile iron piles. In the first, the ultimate friction is related to the effective stress via the so-called β method. The β method is refined into three stages to cover the variety of soils typical of Central Europe. For the driven piles, a different approach is presented in which the ultimate shaft friction is related to the reference hammering time. The recorded hammering time profile is fed directly into the software based on the load-transfer method. Analyses of five loading tests are presented proving that the load transfer method in combination with the β method or the recorded hammering time profile is able to compute the load-displacement curve of both replacement and displacement piles with a reasonable accuracy in various geological conditions. [ABSTRACT FROM AUTHOR]

Piles supporting large structures are often subjected to cyclic lateral loads due to natural phenomena, including earthquakes, winds, and waves. Such loads are main causes of progressive deterioration in the stiffness and reduce the lateral capacity of piles. However, the effects of unsaturated soil conditions on the lateral cyclic response of piles are not yet fully understood, and the p–y curves used in engineering practice are merely based on the assumption of full saturation or complete dry conditions. This study is aimed to investigate the pile performance under unsaturated soil conditions by performing monotonic, cyclic, and post-cyclic loading tests on piles installed in sand with a varying water table. A loading system was designed and constructed to carry out different types of cyclic loadings. It was observed that the lateral capacity of the pile is influenced by the average suction stress along the pile which increases with the depth of the water table. During the cyclic loading, gap formation is noticed around the pile head for tests conducted in unsaturated conditions, which results in significant stiffness degradation compared to the saturated state. However, post-cyclic loading tests showed that the ultimate lateral capacity of the pile is not affected by the cyclic loading history. Finally, a modified p–y curve is proposed for the piles embedded in unsaturated sandy soils, and a comparison of its performance with the observed results is promising. [ABSTRACT FROM AUTHOR]

The objectives were to evaluate the nutritional characteristics of perennial ryegrass silage from pile and plastic bale wrapping system (BWS) from Southern Chile using the Cornell Net Carbohydrate and Protein System. Between 2019 and 2021, 445 pile and 435 BWS silage samples were collected from 158 dairies and analyzed by NIRS. Dry matter (DM) and crude protein were significantly lower in pile than in BWS: 35.2% vs. 42.2% and 13.3% vs. 13.9%, respectively. Lignin and aNDFom were significantly higher in pile than in BWS; 51.43% vs. 49.1%; and 4.52% vs. 3.85%, respectively. Total acids were lower in BWS (4.53%) than in pile silages (6.27%). Assuming a cow consuming 25 kg of DM from each silage, the predicted metabolizable energy and protein to produce milk were significantly higher for BWS (41.8 Mcal and 462.3 g) than pile silages (40.3 Mcal and 296.6 g), respectively. Predicted fecal N, P, and K, and CH4 yield in rumen were higher in BWS than in pile silages. It is suggested that by feeding smaller amounts of BWS silage, similar milk yield can be achieved than feeding a greater amount of pile silage, with a potential lower excretion of N, P, K, and methane to the environment.

Due to the uncertainty of soil condition and pile design characteristics, it is always a challenge for geotechnical engineers to accurately determine the bearing capacity of piles. The main objective of this study is to propose a hybrid model coupling least squares support vector machine (LSSVM) with an improved particle swarm optimization (IPSO) algorithm for the prediction of bearing capacity of piles. The improved PSO algorithm was used to optimize the LSSVM hyperparameters. The performance of the IPSO-LSSVM model was compared with seven artificial intelligence models, namely adaptive neuro-fuzzy inference system (ANFIS), M5 model tree (M5MT), multivariate adaptive regression splines (MARS), gene expression programming (GEP), random forest (RF), regression tree (RT) and a stacked ensemble model. Six statistical indices (e.g., coefficient of determination (R2), mean absolute error (MAE), root mean squared error (RMSE), relative root mean squared error (RRMSE), BIAS and discrepancy ratio (DR)) were used to evaluate the performance of the models. The R2, MAE, RMSE, RRMSE and BIAS values of the IPSO-LSSVM model were 1, 4.27 kN, 6.164 kN, 0.005 and 0, respectively, for the training datasets and 0.9977, 22 kN, 36.03 kN, 0.0275 and –11, respectively, for the testing datasets. Compared with the ANFIS, MARS, GEP, M5MT, RF, RT and the stacked ensemble models, the proposed IPSO-LSSVM model shows high accuracy and robustness on the test datasets. In addition, the sensitivity, uncertainty, reliability and resilience of the IPSO-LSSVM model were also analyzed in this study. First published online 22 October 2024

The response of a pile embedded in crushable sand subjected to earthquake loading is studied using finite elements. For this purpose, a bounding surface plasticity soil model (SANISAND08) is enhanced to incorporate the grain breakage via the evolution in the critical state line. The adaptive Runge–Kutta–Fehlberg stress integration method is adopted for the numerical implementation of the constitutive model. The model is implemented onto the finite element program as user-defined material. The predictive ability of the enhanced model is examined against the laboratory tests, while the pile response is validated based on the simulation results available in the literature. The effect of particle breakage on the pore water pressure ratio development and consequent changes in bending moment, pile skin friction, and pile settlement is assessed under different earthquake loading scenarios. Simulation results show that particle crushing primarily occurs at the initial stages of seismic excitation, and it escalates pore water pressure, leading to liquefaction susceptibility near the pile. Such a rise in pore water pressure considerably increases pile bending moment and reduces skin friction resistance. [ABSTRACT FROM AUTHOR]

Seismic displacements are critical analysis components for evaluating the slope stability during earthquakes and essentially regulated by the yield acceleration of slopes. The conventional Newmark’s method applies the constant yield acceleration to estimate the seismic displacement of slopes, albeit disregarding the time-dependent nature of yield acceleration. This paper presents an efficient analytical method for determining the seismic displacement of Bedding Slopes stabilized with anchor Cables and Piles (BSCP) by considering the dynamic yield acceleration. The dynamic process of yield acceleration was achieved by updating the instantaneous elongation of anchor cables and rotation of piles at each time increment. This was then incorporated within the Newmark’s method to solve the seismic displacement of the BSCP. The results show that the proposed method can reliably predict the general trend of seismic displacement of the BSCP under earthquake loadings, and correlates well with the dynamic finite difference method. Notably, the yield acceleration increases dynamically during the excitation of seismic ground motion and is closely related to the type of earthquake waves. Ignoring the dynamic yield acceleration leads to an overestimation of the post-seismic displacement of the BSCP. Moreover, the proposed method allows for the multi-layer landslide with minor alternations in the formulation of each component of work rates. This study facilitates a better displacement-based seismic design of the BSCP. [ABSTRACT FROM AUTHOR]

In this study, the effects of groundwater level (GWL) fluctuation on settlements of footing and pile in sand were investigated based on results from the centrifuge tests. The effect of GWL fluctuation was significant yet different depending on the type of foundation. Settlements induced by GWL fluctuation were 7.06% (141.2 mm) and 9.13% (27.4 mm) of footing width and pile diameter, respectively, indicating that pile was less sensitive to GWL fluctuation. Settlements of both footing and pile were larger during rising GWL than during falling GWL. With an increase in load level, GWL-induced settlement additionally occurred for both footing and pile. From the particle image velocimetry method (PIV), it was shown that the effect of GWL fluctuation was more significant in a zone with higher load. The load transfer relationship of pile before and after GWL fluctuation revealed that the skin friction increased in the middle part of pile and decreased in the near-surface and lower near-pile tip zones. The FE analysis was performed, and the extended lower-bound (ELB) curves of footing and pile were proposed based on the settlement ratio to quantitatively characterize the effect of GWL fluctuation. [ABSTRACT FROM AUTHOR]

In the random field model's consideration of the spatial variability of soil, soil properties at different locations play different roles in the reliability analysis of the foundation. Investigating the importance distribution of the random field through reliability sensitivity analysis (RSA) is beneficial for understanding how the random field affects the reliability of the foundation. However, many existing RSA methods for the random field model are deficient in terms of efficiency, accuracy, and applicability under complex engineering conditions. Consequently, this study proposes an efficient RSA method for the random field model based on the Karhunen–Loève (KL) expansion method and the first-order reliability method (FORM) to identify the important random field domain in foundation engineering. In the proposed method, the mean reliability sensitivity index (MRSI) is extended to a random field model of continuous form to characterize the importance distribution of the random field. The MRSI is analytically derived based on the results of the KL expansion method and the FORM without additional limit state function (LSF) calculations. Subsequently, the important random field domain, in which the variation of the mean of the soil property contributes significantly to the reliability index, is identified based on the MRSI. Last, two foundation engineering examples that consider the cross-correlated random fields of cohesion and friction angle, including strip footing on single-layer soil and pile in multiple-layer soil, were used to verify the proposed method. The results showed that an important random field domain with a small area dominates the variation of the reliability index of a foundation, and important random field domain area increases with autocorrelation distance (ACD). This innovative identification method holds great engineering significance, because it allows geotechnical practitioners to gain a comprehensive understanding of the failure modes and foundation treatment areas of foundations in spatially varying soil. In the random field model's consideration of the spatial variability of soil, soil properties at different locations play different roles in the reliability analysis of the foundation. Investigating the importance distribution of the random field through RSA is beneficial for understanding how the random field affects the reliability of the foundation. However, many existing RSA methods for the random field model are deficient in terms of efficiency, accuracy, and applicability under complex engineering conditions. Consequently, this study proposes an efficient RSA method for the random field model to identify the important random field domain, in which the variation of the mean of the soil property contributes significantly to the reliability index. Two foundation engineering examples that consider the cross-correlated random fields of cohesion and friction angle, including strip footing on single-layer soil and pile in multiple-layer soil, were used to verify the proposed method. The results showed that the innovative identification will allow geotechnical practitioners to gain a comprehensive understanding of the failure modes and foundation treatment areas of foundations in spatially varying soil. [ABSTRACT FROM AUTHOR]

The numerical hydrodynamic experiments on SolidWorks modeling of a pile grillage made it possible to determine the loads on and the reactions of structures taking into account the time factor. The grillage design is optimized so that the distribution of pressure over the lateral surface of the piles is uniform. [ABSTRACT FROM AUTHOR]

Background: Hemorrhoidal diseases are very common diseases found in surgical outpatient clinics, affecting populations all over the world. Treatments for the different grades of hemorrhoids include lifestyle changes, conservative medical therapy, and operative interventions. Objective: To assess the conservative treatment response of all grades of hemorrhoidal disease (grades 1-4) to a venotonic agent (Daflon 500mg). Patients and Methods: This is a prospective observational study of 196 patients with hemorrhoids, conducted during the period from January 2015 to January 2020, All treated with the standard dose of a venotonic agent (Daflon 500mg). An observation of the reduction and disappearance of the signs and symptoms of the different grades of the disease was done at 1, 3, and 6 months. Results: The mean age of the patients was 46.6 (range 14--85) years. The majority (41.84%) were diagnosed with grade III hemorrhoidal disease and 30.1% with grade II disease; Grade I and Grade IV constitute 9.69% and 18.37%, respectively. excellent improvement observed in about 72.45%, temporary response seen in 15.82% of cases. Conclusion: Daflon 500 mg is an effective first-line conservative treatment for all four grades of hemorrhoidal diseases, including grade 4, which has a 44.74% permanent response rate. This medical treatment, in turn, reduces the chance of surgical intervention and its complications. [ABSTRACT FROM AUTHOR]

The design of large-scale pile foundation systems is routinely assisted by finite element simulations. To a large extent, both the modeling and the computational effort of such analyses are governed by the adopted pile modeling technique. The traditional approach to this problem fully resolves the pile and soil domain employing solid elements, resulting in considerable meshing constraints and high simulation runtimes that may be regarded as unbearable for many practical purposes. As an attractive alternative to circumvent these obstacles, embedded FE models have become increasingly popular in solving this modeling task, mainly due to their flexible meshing procedure and significantly enhanced runtime efficiency. In a preceding contribution, the authors have proposed an extended formulation that provides a rigorous framework to capture soil-structure interaction effects at the physical soil-pile contacts. As a key feature, the implemented combined soil-pile coupling scheme explicitly accounts for endpoint interaction. However, validation studies have been constrained to single pile analyses to date. The present work expands this validation scope to large-scale boundary value problems involving multiple piles and investigates the model performance based on three different case studies. The results are compared to both, measurements and numerical benchmark solutions and provide exclusive insight into the numerical fidelity of the developed embedded FE model, with a view to increasing its potential for take-up in engineering practice.

The paper presents two applications (software packages) in which the load-transfer method is used for axially loaded Kelly drilled bored piles and displacement ductile iron piles. In the first, the ultimate friction is related to the effective stress via the so-called β method. The β method is refined into three stages to cover the variety of soils typical of Central Europe. For the driven piles, a different approach is presented in which the ultimate shaft friction is related to the reference hammering time. The recorded hammering time profile is fed directly into the software based on the load-transfer method. Analyses of five loading tests are presented proving that the load transfer method in combination with the β method or the recorded hammering time profile is able to compute the load-displacement curve of both replacement and displacement piles with a reasonable accuracy in various geological conditions.

The primary objective of this study is to examine the suitability of employing a machine learning models (MLMs) comprising Support Vector Machine (SVM), Gene Expression Programming (GEP), and Artificial Neural Network (ANN) algorithms to emulate the influence of geometric and geotechnical parameters of the piles on the scour depth reduction about the oblong-shaped bridge pier. A dataset consisting of 90 laboratory observations was utilized, allocating 70 % of the data for the training and 30 % for the testing the MLMs. An oblong-shaped bridge pier of diameter D, was positioned and subjected to a rectangular flume featuring an erodible bed comprising sand sediment particles of D50 = 1.7 mm under clear water and subcritical flow conditions. The spacing between the piles, LD, the angle of pile orientation with respect to the flow, θ, and the Froude number, Fr, were identified as independent parameters through the dimensional analysis and Buckingham-Π theory. The MLMs’ performance were assessed employing root mean square error (RMSE), mean absolute error (MAE), coefficient of determination (R2), and developed discrepancy ratio (DDR). The outcomes, affirming the predictive capacity of all MLMs included, revealed that the GEP model employing a three-gene configuration exhibited superior accuracy compared to the other two MLMs. Specifically, the performance indicators (RMSE, MAE, R2, DDR) during the training and testing phases were (0.0433, 0.033, 0.981, 6.8) and (0.054, 0.045, 0.958, 4.81) respectively. The sensitivity analysis elucidated the hierarchy of influential variables as follows: Fr, LD and θ.

Introduction. The article discusses the requirements for equipment for removing pile caps of reinforced concrete piles. The machines produced nowadays have excessive power and strength parameters which has been noted and proved experimentally.Materials and methods. Using a prototype of operational equipment on the different piles of different cross-section the force parameters of the working process, the character of development of cutting resistance forces in the cycle were investigated.Results. The stick-slip nature of cutting resistance forces and then a sharp drop of these forces on the whole area of theoscillogram indicates the brittle character of the pile fracture. It is also noted that the dependence of head shearing resistance forces on the height of the pile cap is linear. Technological and constructive features of the new equipment were investigated. High productivity of the machine as a whole was shown.Discussion and conclusion. Based on the results of the tests, the authors concluded that further work on the study of the working process of removal of reinforced concrete pile caps is reasonable.

The overall reinforcement of soft soil foundation has the disadvantages of large engineering quantity and high cost. When the pile foundation bears horizontal loads in the soil, the mechanical properties of the soil near the surface have a greater impact on it compared to the deep soil. Therefore, studying the influence of shallow soil reinforcement on the horizontal bearing capacity of pile foundations has important engineering significance. Studying the influence of shallow soft soil reinforcement around piles on the horizontal bearing performance of piles is of great significance for improving the economic efficiency of pile foundation reinforcement technology in soft soil areas. In this paper, seven pile-soil finite element models are established based on ABAQUS 2022 software to study the influence of shallow reinforcement on the horizontal bearing capacity of single pile. The models were established on the basis of a field test and its validity was verified. The influence of different reinforcement degrees on the horizontal bearing capacity of piles is analyzed by taking the reinforcement width and reinforcement depth as variables. The results indicate that shallow ground improvement significantly enhances the horizontal bearing capacity of the pile. The horizontal bearing capacity of the pile is increased by 83.0%, 104.3%, and 224.4%, respectively, corresponding to a reinforcement width of 2 times, 3 times, and 4 times the diameter of the pile, respectively. With the increase of the reinforcement width, the bending moment and deformation of the pile under the same horizontal load decrease significantly, while it has no significant effect on the location of the maximum bending moment of the pile. The bearing capacity of the pile foundation gradually increases with the increase of the reinforcement depth. Compared with the unreinforced situation, the horizontal bearing capacity of the pile body is increased by 224.4%, 361.3%, and 456.8%, respectively, corresponding to a reinforcement depth of 0.1 times, 0.2 times, and 0.3 times the pile length. As the reinforcement depth increases, the corresponding increase in bearing capacity does not increase linearly, but gradually decreases. This indicates that blindly carrying out deep soil reinforcement without comprehensive evaluation is not advisable.

Seismic design of prestressed concrete piles requires transverse spiral reinforcement to be proportioned to confine and thus retain an intact concrete core during inelastic rotation cycles. Prescriptive provisions of the International Building Code require a prescriptive minimum volumetric ratio of confinement reinforcement relative to the pile cross section and a minimum in-ground depth to which the confinement reinforcement must extend. This study seeks to determine a practical maximum depth to maximum in-ground bending moment for 12, 14, and 16 in. (300, 360, and 410 mm) prestressed concrete piles subjected to displacement consistent with lateral seismic loads. A commercially available lateral analysis software was used to conduct a parametric analytical study of square and octagonal piles embedded in substantially varied soil conditions. Piles were modeled to remain elastic. Depth to maximum in-ground moment was recorded. Maximum depth values for each pile type were reported. Analysis of results indicates that prescriptive depth requirements may be overly conservative for 12 and 14 in. square piles in nonliquefiable soils. It was concluded that a reduction could be made to the code-prescribed depth of ductile reinforcement for some pile types in nonliquefiable conditions. [ABSTRACT FROM AUTHOR]