The Publication of the Piling Canon in the Late Qing

Piling Canon refers to a woodblock-printed Chinese Buddhist Canon during the late Qing Dynasty.Despite its historical significance,it has received limited attention from the academia,as its discovery took place after the turn of the 21st century.This study explores the background,supervisor,proofreader,engravers,donors,and other factors that contributed to the publication of the Piling Canon.It was supervised by Buddhist monk Qingrong in Changzhou Tianning Monastery from 1908 to 1926,due to the commission of Yang Wenhui.By investigating the historical records in the colophons of Piling Canon,we found that engraving locations are distributed in Hubei,Yangzhou,and Danyang which engravers operated in groups;the majority of donors were found to be individuals and group forms,social fundraising was included as well.It is noteworthy that Sheng Xuanhuai made a significant contribution in terms of funding.Furthermore,the production of the Piling Canon confirms to the commence of Buddhism revival,as Buddhist scriptures in Jiangnan regions were almost destroyed after the Taiping Rebellion.The research shed light on extensive participation of cultural celebrities,diverse donation forms,and excellent engraving,offering a vivid depiction of Buddhist belief and social landscape in Jiangnan region.

Anchoring Depth Research of Anti-Slide Piles of Anchor Bar in Soil

The model test result of earth force in the side of anti-slide pile of anchor bars was introduced.There are three groups of the tests.The loads were on the back side of the slope in two groups.The other one was loaded just behind the pile by the jack.In order to get the force of the soil,some earth-pressure boxes were used to get the earth pressure on the side of the piles.The part of the max pressure and the earth pressure was mainly focused under the slip line

Study of seismic behavior of PHC piles with partial normal-strength deformed bars

Nine PHC piles with partial normal-strength deformed bars were prepared in present study,and cyclic loading tests were implemented to evaluate these piles’seismic performance.The influence of the axial compression ratio and the amount of normal-strength deformed bars on failure modes,crack patterns,strength,stiffness,and ductility were examined.The test findings indicate that the change of axial compression ratio has a noticeable influence on the failure mode of PHC piles.A larger axial compression ratio results in a higher cracking bending resistance,ultimate bending resistance,and initial stiffness,but the propagation heights of flexural cracks decrease as the axial compression ratio increases.Furthermore,increasing the amount of normal-strength deformed bars causes a slight decrease in ductility.Finally,a calculation formula was proposed to predict the flexural capacity of PHC piles with partial normal-strength deformed bars.

Controlled rocking pile foundation system with replaceable bar fuses for seismic resilience

Bridges designed following a conventional approach minimize the risk of collapse,but often require challenging,costly,and time-consuming restoration after an earthquake occurs.The new seismic design philosophy requires bridges to maintain functionality even after severe earthquakes.In this context,this paper proposes a controlled rocking pile foundation(CRPF)system and numerically evaluates bridges′degree of seismic resilience.The CRPF system allows a pile cap to rock on a pile foundation and dissipate seismic energy through inelastic deformations of replaceable bar fuses that connect a pile cap and piles.Following the conceptual design of the CRPF system,two analytical models were developed for a bridge pier utilizing the CRPF system and a pier designed to develop a plastic hinge in its column.The analytical results indicate that,after experiencing a severe earthquake,a conventionally designed bridge pier sustained substantial damage in its column and exhibited significant residual displacement.In contrast,a pier using the CRPF system showed negligible residual displacement and maintained elastic behavior except,as expected,for bar fuses.The damaged fuses can be rapidly replaced to recover bridge seismic resistance following an earthquake.Therefore,the CRPF system helps to achieve the desired postearthquake performance objectives.

Cast-in-place concrete thin-wall pipe pile as barrier for vibration isolation

Three dimensional analysis was performed by regarding vibration isolation performance cast-in-place concrete thin-wall pipe pile (PCC) and using the finite element analysis software ANSYS. The ground vertical amplitude was analyzed behind the single row cast-in-place concrete thin-wall pipe pile after the source vibration, and the influencing factors were also studied. The results indicate that in the one time of wavelength before the barrier, the oscillation amplitude is weakened; meanwhile the range which covers 4 times wavelength behind the barrier has a good vibration isolation effect, when the distance is larger than the barrier latter 4 times wavelength vibration isolation expiration.

Theoretical analysis of a row of piles as passive barriers and an equivalent in-filled trench model

A theoretical study on the ground vibration isolation efficiency by a row of piles as passive barrier in a three-dimensional context was presented. The analysis was accomplished with the aid of integral equations governing Rayleigh wave scattering, used to predict the complicated Rayleigh wave field generated by a number of irregular scatters embedded in an elastic half-space. Then, the passive isolation effectiveness of a row of piles for screening Rayleigh wave was studied in detail. The effects of relevant parameters on the screening effectiveness were investigated and analyzed from the perspective of equivalence with in-filled trench. The results show that using a row of rigid piles as wave barrier is more effective than that of flexible ones, and an optimum reduction of vibration can be achieved either by increasing the size of piles or by decreasing the net spacing between the piles. Finally, based on the derived integral equation for Rayleigh wave scattering, the principle of equivalent modeling of the barrier of piles by an in-filled trench is put forward, which simplifies the analysis of vibration isolation by a row of piles.

Port and Marine Structures Made of Sheet Piling with Staggered Toe

Some new approaches to designing and calculation of maritime structures made of sheet piling with staggered toe are considered and discussed. Obtained results allow determination of piles spacing efficiency in staggered embedment wall. The specificity of interaction of piles in ＂comb＂ with the soil foundation Practical application is illustrated by example of calculation. regarding transition from continuous to ＂comb＂ wall is investigated.

Optimal Piling Network Corrosion Protection System for Al-Zubair Harbor

Cathodic protection is an effective electrochemical technique for preventing corrosion of metallic structures, for large structures like piles network impressed current cathodic protection (ICCP) system is usually preferred. The main aim of this study is to obtain the optimum protection potential that would provide a full cathodic protection for steel piles net-work immersed in sea water at Al-Zubair harbor. The effect of one immeasurable factor (path of anode (χ1)) and two measurable factors (position of anode (χ2) and voltage of power supply (χ3)) on protection potential are studied. Each factor has three different levels (high, medium, and low). Twenty-seven experiments were conducted based on a full factorial design of experiments. The results show that, a sufficient protection for three cathodes can be provided through the electrical circuit connecting them within the appropriate geometric shape.The protection potential is icreased with increasing the voltage of power supply and decreasing of distance between the anode and cathodes (piles network).

Improvement of Technological Solutions for Sheet Piling Walls Made of U-Shape Piles

As it is evident from the practice of construction and maintenance of thin retaining walls, the degree of developing of frictional forces in interlock connections of steel sheet U-shape piles essentially influences the realization of the values of geometric characteristics of the piles cross-section （the moment of inertia and the section modulus） reduced to the length unit of the construction. The article offers new and simple solutions for realization and economically effective technological approaches to provide joint work of the sheet piles being considered, which improve the adequacy of design and reliability of maintenance of thin retaining walls.

Fiber optic monitoring of an anti-slide pile in a retrogressive landslide

Anti-slide piles are one of the most important reinforcement structures against landslides,and evalu-ating the working conditions is of great significance for landslide mitigation.The widely adopted analytical methods of pile internal forces include cantilever beam method and elastic foundation beam method.However,due to many assumptions involved in calculation,the analytical models cannot be fully applicable to complex site situations,e.g.landslides with multi-sliding surfaces and pile-soil interface separation as discussed herein.In view of this,the combination of distributed fiber optic sensing(DFOS)and strain-internal force conversion methods was proposed to evaluate the working conditions of an anti-sliding pile in a typical retrogressive landslide in the Three Gorges reservoir area,China.Brillouin optical time domain reflectometry(BOTDR)was utilized to monitor the strain distri-bution along the pile.Next,by analyzing the relative deformation between the pile and its adjacent inclinometer,the pile-soil interface separation was profiled.Finally,the internal forces of the anti-slide pile were derived based on the strain-internal force conversion method.According to the ratio of calculated internal forces to the design values,the working conditions of the anti-slide pile could be evaluated.The results demonstrated that the proposed method could reveal the deformation pattern of the anti-slide pile system,and can quantitatively evaluate its working conditions.

Centrifuge modeling of unreinforced and multi-row stabilizing piles reinforced landslides subjected to reservoir water level fluctuation

With the construction of the Three Gorges Reservoir dam,frequent reservoir landslide events have been recorded.In recent years,multi-row stabilizing piles(MRSPs)have been used to stabilize massive reservoir landslides in China.In this study,two centrifuge model tests were carried out to study the unreinforced and MRSP-reinforced slopes subjected to reservoir water level(RWL)operation,using the Taping landslide as a prototype.The results indicate that the RWL rising can provide lateral support within the submerged zone and then produce the inward seepage force,eventually strengthening the slope stability.However,a rapid RWL drawdown may induce outward seepage forces and a sudden debuttressing effect,consequently reducing the effective soil normal stress and triggering partial pre-failure within the RWL fluctuation zone.Furthermore,partial deformation and subsequent soil structure damage generate excess pore water pressures,ultimately leading to the overall failure of the reservoir landslide.This study also reveals that a rapid increase in the downslope driving force due to RWL drawdown significantly intensifies the lateral earth pressures exerted on the MRSPs.Conversely,the MRSPs possess a considerable reinforcement effect on the reservoir landslide,transforming the overall failure into a partial deformation and failure situated above and in front of the MRSPs.The mechanical transfer behavior observed in the MRSPs demonstrates a progressive alteration in relation to RWL fluctuations.As the RWL rises,the mechanical states among MRSPs exhibit a growing imbalance.The shear force transfer factor(i.e.the ratio of shear forces on pile of the n th row to that of the first row)increases significantly with the RWL drawdown.This indicates that the mechanical states among MRSPs tend toward an enhanced equilibrium.The insights gained from this study contribute to a more comprehensive understanding of the failure mechanisms of reservoir landslides and the mechanical behavior of MRSPs in reservoir banks.

考虑锚杆拉剪破断特性的锚固系统数值模拟与应用

基于FLAC3D数值模拟软件,考虑锚杆拉剪破断特性,通过FISH语言将pile单元进行修正,反映了锚杆的拉剪破断特性;并且引入了锚固界面的黏结滑移模型,模拟了锚固界面的应变软化行为。将修正的锚杆模型进行验证分析,与室内试验结果吻合良好,且能够较好地反映锚固界面的黏结滑移力学行为和锚杆杆体的破断行为。以中关铁矿为研究对象,开展了修正锚杆模型的应用研究,研究结果可为地下锚固工程稳定性分析提供借鉴。

Experimental study on seismic reinforcement of bridge foundation on silty clay landslide with inclined interlayer

A shaking table test for a bridge foundation reinforced by anti-slide piles on a silty clay landslide model with an inclined interlayer was performed.The deformation characteristics of the bridge foundation piles and anti-slide piles were analyzed in different loading conditions.The dynamic response law of a silty clay landslide with an inclined interlayer was summarized.The spacing between the rear anti-slide piles and bridge foundation should be reasonably controlled according to the seismic fortification requirements,to avoid the two peaks in the forced deformation of the bridge foundation piles.The“blocking effect”of the bridge foundation piles reduced the deformation of the forward anti-slide piles.The stress-strain response of silty clay was intensified as the vibration wave field appeared on the slope.Since the vibration intensified,the thrust distribution of the landslide underwent a process of shifting from triangle to inverted trapezoid,the difference in the acceleration response between the bearing platform and silty clay landslide tended to decrease,and the spectrum amplitude near the natural vibration frequency increased.The rear anti-slide piles were able to slow down the shear deformation of the soil in front of the piles and avoid excessive acceleration response of the bridge foundation piles.

Hybrid response surface method for system reliability analysis of pilereinforced slopes

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.

Experimental Study of Local Scour Around Four Piles Under Different Attack Angles and Gap Ratios

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.

Theoretical investigation on axial cyclic performance of monopile in sands using interface constitutive models

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 loadtransfer 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.

Pile foundation in alternate layered liquefiable and non-liquefiable soil deposits subjected to earthquake loading

Pile foundations are still the preferred foundation system for high-rise structures in earthquake-prone regions.Pile foundations have experienced failures in past earthquakes due to liquefaction.Research on pile foundations in liquefiable soils has primarily focused on the pile foundation behavior in two or three-layered soil profiles.However,in natural occurrence,it may occur in alternative layers of liquefiable and non-liquefiable soil.However,the experimental and/or numerical studies on the layered effect on pile foundations have not been widely addressed in the literature.Most of the design codes across the world do not explicitly mention the effect of sandwiched non-liquefiable soil layers on the pile response.In the present study,the behavior of an end-bearing pile in layered liquefiable and non-liquefiable soil deposit is studied numerically.This study found that the kinematic bending moment is higher and governs the design when the effect of the sandwiched non-liquefied layer is considered in the analysis as opposed to when its effect is ignored.Therefore,ignoring the effect of the sandwiched non-liquefied layer in a liquefiable soil deposit might be a nonconservative design approach.

Thermal performance of cast-in-place piles with artificial ground freezing in permafrost regions

During the construction of cast-in-place piles in warm permafrost,the heat carried by concrete and the cement hydration reaction can cause strong thermal disturbance to the surrounding permafrost.Since the bearing capacity of the pile is quite small before the full freeze-back,the quick refreezing of the native soils surrounding the cast-in-place pile has become the focus of the infrastructure construction in permafrost.To solve this problem,this paper innovatively puts forward the application of the artificial ground freezing(AGF)method at the end of the curing period of cast-in-place piles in permafrost.A field test on the AGF was conducted at the Beiluhe Observation and Research Station of Frozen Soil Engineering and Environment(34°51.2'N,92°56.4'E)in the Qinghai Tibet Plateau(QTP),and then a 3-D numerical model was established to investigate the thermal performance of piles using AGF under different engineering conditions.Additionally,the long-term thermal performance of piles after the completion of AGF under different conditions was estimated.Field experiment results demonstrate that AGF is an effective method to reduce the refreezing time of the soil surrounding the piles constructed in permafrost terrain,with the ability to reduce the pile-soil interface temperatures to below the natural ground temperature within 3 days.Numerical results further prove that AGF still has a good cooling effect even under unfavorable engineering conditions such as high pouring temperature,large pile diameter,and large pile length.Consequently,the application of this method is meaningful to save the subsequent latency time and solve the problem of thermal disturbance in pile construction in permafrost.The research results are highly relevant for the spread of AGF technology and the rapid building of pile foundations in permafrost.

Determination of the Pile Drivability Using Random Forest Optimized by Particle Swarm Optimization and Bayesian Optimizer

Driven piles are used in many geological environments as a practical and convenient structural component.Hence,the determination of the drivability of piles is actually of great importance in complex geotechnical applications.Conventional methods of predicting pile drivability often rely on simplified physicalmodels or empirical formulas,whichmay lack accuracy or applicability in complex geological conditions.Therefore,this study presents a practical machine learning approach,namely a Random Forest(RF)optimized by Bayesian Optimization(BO)and Particle Swarm Optimization(PSO),which not only enhances prediction accuracy but also better adapts to varying geological environments to predict the drivability parameters of piles(i.e.,maximumcompressive stress,maximum tensile stress,and blow per foot).In addition,support vector regression,extreme gradient boosting,k nearest neighbor,and decision tree are also used and applied for comparison purposes.In order to train and test these models,among the 4072 datasets collected with 17model inputs,3258 datasets were randomly selected for training,and the remaining 814 datasets were used for model testing.Lastly,the results of these models were compared and evaluated using two performance indices,i.e.,the root mean square error(RMSE)and the coefficient of determination(R2).The results indicate that the optimized RF model achieved lower RMSE than other prediction models in predicting the three parameters,specifically 0.044,0.438,and 0.146;and higher R^(2) values than other implemented techniques,specifically 0.966,0.884,and 0.977.In addition,the sensitivity and uncertainty of the optimized RF model were analyzed using Sobol sensitivity analysis and Monte Carlo(MC)simulation.It can be concluded that the optimized RF model could be used to predict the performance of the pile,and it may provide a useful reference for solving some problems under similar engineering conditions.

Numerical modelling for predicting corrosion initiation life of reinforced concrete square piles under reverse-seepage pressure

Square piles of reinforced concrete(RC)in marine environments are susceptible to chloride-inducedcorrosion.A novel reverse-seepage technique(RST)is applied to square piles to block the intrusion of chlorides.Thisresearch introduces a computational model designed to predict the lifespan of corrosion initiation in reinforced concretesquare piles when applied reverse-seepage pressure.The model considers the impacts of chloride binding and the tripletime-dependence property among the permeability,the corrected surface chloride concentration,and the diffusioncoefficient.The proposed numerical model is solved using the alternating direction implicit(ADI)approach,and itsaccuracy and reliability are evaluated by contrasting the computational outcomes with the analytical solution andexperimental results.Furthermore,the primary factors contributing to the corrosion of reinforced concrete square pilesare analyzed.The results indicate that applying RST can decrease the chloride penetration depth and prolong the lifespanof corrosion initiation in square piles.The water-cement ratio and reverse seepage pressure are the most influentialfactors.A water pressure of 0.4 MPa can double the life of concrete,and the durable life of concrete with a water-cementratio of 0.3 can reach 100 years.