Pile Bending Moment Research Articles

Seismic response of nuclear power station with disconnected pile-raft foundation using dynamic centrifuge tests

The typical foundation type for a nuclear power station is the raft foundation in rock areas. With the power demand, it is possible that a nuclear power station located in soft soil areas. Traditional connected pile raft foundation (CPRF) has been successfully used in soft soil areas. However, under earthquake loads, high horizontal shear stresses and bending moments are generated in the pile head. Accordingly, researchers have sought to develop an innovative disconnected pile raft foundation (DPRF), and the benefits of DPRF have simulated increasing researches on it in the last two decades. In this study, a series of dynamic centrifuge tests were carried out to identify the effect of cushion and its thickness on the dynamic characteristics of the nuclear power station with DPRF. A withe noise excitation and three earthquake waves with different seismic intensities were adopted as ground motion. The seismic responses of soil, structure, and bending moment of piles were analysed. A cushion thickness equal to the diameter of piles is recommended. Comparing with the CPRF, the cushion layer of DPRF has an isolation benefit. With the gravel cushion, attention must be paid to the horizontal displacement, inclination and rocking of the superstructure.

Study on combination of p-y models for laterally loaded pile in offshore wind farm

The p-y curve method recommended by American Petroleum Institute (API) code is a mainstream design method of the laterally loaded large-diameter piles for offshore wind turbines. However, it has been long recognized that the conventional p-y models proposed for piles with a relatively large length to diameter ratio may not be appropriate for the large-diameter piles. In this study, the field tests of laterally loaded pile are analyzed in detail, particularly the bending moment and lateral displacement under multistage cyclic loading. The bending moment and lateral displacement of test pile are calculated by several combinations of clay p-y model and sand p-y model. A modified p-y model for clay is proposed considering the influence of pile diameter, and a modified p-y model for sand is proposed introducing the effect of sand layer depth and pile diameter on initial stiffness. The results indicate that the effect of pile diameter on p-y model for clay is apparent, and the influence coefficient of pile diameter on the critical parameter yc is recommended as 0.2–0.5. For the silty sand close to seabed, the formula of initial foundation stiffness of silty sand recommended by Sorensen appears to be more reasonable, and the initial foundation stiffness of silty sand at depth is suggested to calculate with formula suggested by Kallehave et al.

Typical site seismic response analysis with reinforcement under earthquake and rainfall in the mountainous areas of China

Multi-tilted layered soil is widespread in the mountainous areas of China, and pile systems are widely applied to foundation support and repair. In order to investigate the seismic response of pile systems in multi-tilted layered soils under earthquake and rainfall, two models were built and tested through a large 1-g shaking table. The interlayer was tilted and highly weathered, and it was saturated during rainfall. The piles were embedded in the bedrock with different lengths. The results showed that: 1) The acceleration response was weakened in the interlayer, and it diminished as the earthquake amplitude increased. The structures showed the maximum acceleration response. 2) The existence of water in the tilted interlayer led to a greater response of the superstructure. The bending moment of piles varied under different containers, which was mainly due to the inertial force of the container and the potential sliding force of the covering layer. The water in the interlayer from rainfall promoted the bending moment caused by the potential sliding force, increasing the potential risk of instability of the system. 3) The motion mode of the container under rainfall was translation. The rotation angle of the container with saturated moisture content was significant and it increased with the increase of the earthquake amplitude.

Large Scale Model Test Study of Foundation Pit Supported by Pile Anchors

Due to the special time–space and environmental effects of the foundation pit, there are many unstable factors in the construction process of the field test. The indoor model test can avoid many uncertainties in the construction process due to its operability, which can reduce the interference with the test results and improve the accuracy of the test. In order to further discuss the force-bearing characteristics and deformation laws of loess pits’ support structure in Northwest China, a large model test of foundation pit supported by a pile anchor with a geometric similarity ratio of 1:10 was designed and completed. The force and deformation characteristics of the support structure were systematically studied by simulating the conditions of additional load at the pit edge, soil layered excavated, and anchors tensioned. The test results show that: for the pile-anchor support structure, the anchors have significant limiting effects on the displacement of the piles. Especially, when the position of the first row of anchors is closer to the pile top, the displacement of the pile is smaller. The stress state of the piles was changed by the prestressed anchor. The passive stress state of piles is changed from one side of tension and the other side of compression to the active stress state of “S” shape, which makes the distribution of the bending moment of piles more reasonable. The measured earth pressure in the process of soil unloading has a nonlinear distribution, which is different from the classical Rankine earth pressure distribution; specifically, the passive earth pressure in front of the pile is more obvious. In addition, the prestress applied to the anchors has a more significant effect on the internal forces of the other anchors. Compared with sequential tensioning, the prestress loss caused by interval hole tensioning is significantly reduced. The greater the number of spaced holes, the smaller the prestress loss and the better the anchoring effect of the anchor. The results of the study can provide reference for similar model tests, and also for related engineering applications.

Effects of various factors on behaviors of piles and foundation soils due to seismic shaking

Buckling instability has been identified as a possible mechanism of pile failure in liquefiable ground and this failure mechanism is not explicitly mentioned in most of the design codes. Pile buckling would be affected, however, by various factors including liquefaction zone of foundations soils, axial loads of piles, geometry as well as arrangement of pile foundation, etc. An efficient approach using deterministic by Bhattacharya is proposed to compute the buckling instability in pile. This method is verified and validated using 3D finite-element simulation through OpenSeesPL. A more comprehensive study of numerical simulation would include the effects of various factors on the responses of piles and foundations soils due to seismic loading. The findings reported that an increase in axial loading would generally increase the excess pore pressure in soils and would generally increase the deflection and bending moment in piles and acceleration responses in soils. An increase in pile spacing would generally increase the deflection and bending moment in piles, as a result of more soil volume among the piles. An increase in diameter of pile would increase in rigidity and maximum bending capacity of piles and thus would resist more energy released in liquefiable ground that amplifies the deflection (curvature) of pile. A comparison of two approaches confirms the pile would be safe from buckling failure against soil liquefaction during seismic loading. Finally, this study would provide for predicting pile buckling instability and the behaviors of piles and foundation soils due to seismic shaking and liquefied ground.

Nonlinear numerical simulation of dynamic response of pile site and pile foundation under earthquake

AbstractTo study the influence of the nonlinear connection of pile and soil on the dynamic response characteristics of the pile foundation, this article proposes to study the dynamic response of the bridge pile foundation to the slope by combining the centrifugal shaking table test and OPENSEES open source finite element program. This article introduces the pressure-dependent multiyield surface model based on confining pressure. Through the inverse calculation of the similarity ratio of the centrifuge model test, the OPENSEES two-dimensional nonlinear finite element model of the pile group in the slope section can be established. The centrifuge shaking table test is to input the preset seismic wave horizontally at the bottom of the model box. The form of seismic wave is El Centro wave verification of two-dimensional finite element model of the pile group in slope section under earthquake. The reliability of the model is verified by comparing the test and calculated values of dynamic response (residual horizontal displacement and final bending moment) of the pile body under five different peak acceleration seismic wave loading conditions. In the dynamic response experiment of slope pile foundation, in the embedded part below the bedrock surface, the residual horizontal displacement of each pile body is zero. Constrained by the cap beam and tie beam, the displacement of the free section of the pile group at these two positions is basically the same. Through comprehensive analysis, the displacement of P1 and P2 piles is basically the same. The calculated value of the final bending moment of P1 and P2 piles shows the same change trend as the test value, and the test value is slightly larger than the calculated value. The relative errors of the maximum final bending moment of P1 pile under each loading condition are 7.4, 7.8, 12.6, 3.9, and 9.6%, respectively, and the relative errors of P2 pile are 4.6, 3.6, 12.5, 13.6, and 11.5%, respectively. The analysis relative error is caused by the elastic element used in the calculation of the pile body, which is different from the mechanical behavior of the simulated pile body material in the test. Dynamic response of slope site according to the existing centrifuge test results can be seen that the deformation at the slope shoulder of slope site is the most obvious under the earthquake. The inclined interface of soft and hard rock and soil layer will aggravate the dynamic response of the overburden layer on the slope, weakening its ability of seismic energy consumption.

Assessment of Earth Retaining Performance for Long-Short Piles Composite Structures from Field Experiments and Numerical Analysis

Retaining pile structure is commonly utilized in excavation maintenance design. In recent years, the long-short combined retaining piles have received more and more attention. According to the actual deep excavation engineering, the working mechanism of the long-short, long-double-short, and long-triple-short combined retaining piles was tested in the field. Based on the field test parameters, the finite element model of the test area was established and the simulation results were verified, and the effects of short pile length and pile spacing on bending moment, horizontal displacement of piles, surface settlement, and excavation bottom heave were further investigated. The results show that the bending moment of the long pile is larger than the short pile. The bending moment of the long pile and short pile increases gradually with the increase in the number of short piles. When the combination changes from combination 1 to 3, the peak moment of the long pile and short pile increases by 15.8% and 15.2%, respectively. The maximum displacement is near the pile top, combination 3 has the largest horizontal displacement, and the peak displacement of the long pile and the short pile is 17.21 mm and 17.87 mm, respectively, but almost no effect exists on the horizontal displacement below the excavation bottom. In addition, reducing short pile length and increasing pile spacing will increase bending moment and horizontal displacement of the long and short piles to a certain extent, and this phenomenon is mainly concentrated above the excavation bottom, the influence of short pile length and pile spacing on surface settlement and excavation bottom heave can be ignored.

Data Analysis of the Effect of Different Nanomaterials on Antislide Pile Performance in Railway Landslides

Engineering geological conditions in our country are complex and diverse. Many high-rise buildings, bridges, and launch towers are inevitably built on high and steep slopes. Heavy rain, earthquake, human engineering activities, and other factors lead to frequent landslides, soil creep deformation, and overall sliding, resulting in a certain bending moment and flexural deformation of foundation piles, may cause damage to the substructure and foundation pile failure, and then endanger the safety of the superstructure. In the past, bridge pile group foundation was used in bridge pile foundation engineering to improve the impact situation, but the stress environment of bridge pile foundation in landslide is obviously different from that of bridge pile foundation in the flat area. The large deformation of soil in front of the pile will easily cause the phenomenon of soil sliding and peeling, which will increase the technical difficulty of antislide pile construction. Based on this, this study firstly briefly introduces the relevant theories and technologies of railway landslide antislide pile technology and then establishes the static model of railway landslide antislide piles with different nanomaterials. Finally, the reinforcement technology of different nanomaterial antislide piles for railway landslide is expounded, which can provide guarantee for the application of different nanomaterial antislide piles for railway landslide. The results show that the preloading is carried out according to 1/10 of the design load to reduce the void between the soils. After the load is maintained for 2 hours, the load is unloaded to 0, and good skid resistance can be obtained.

Numerical investigation of the effect of particle gradation on the lateral response of pile in coral sand

This paper addresses the effect of particle gradation on the lateral response of pile in coral sand foundation through numerical method. Firstly, the parameters of Hypoplastic (HP) constitutive model were calibrated by a series of laboratory tests and show obvious difference in value between fine and coarse coral sand. Subsequently, a 50 g centrifuge test and 1g model pile test were carried out to verify the numerical model and calibrated parameters. Afterward, numerical analyses were systematically conducted to investigate the influence of particle gradation, buried depth, and relative density on the lateral response of pile. The lateral load–displacement response, deflection and bending moment of pile, and soil resistance were analyzed and discussed in detail. Numerical results show that the bearing capacity of pile and soil resistance in coarse sand are greater than those in fine coral sand when the relative density is 25 % or 50 %. However, when the relative density is 75 %, the bearing capacity of pile and soil resistance in fine sand present significantly greater values than those in coarse sand under higher lateral displacement level. Moreover, the difference in lateral response of pile between coarse and fine coral sand is more significant in looser sand or shorter pile.

New p-y model for seismic loading prediction of pile foundations in non-liquefiable and liquefiable soils considering modulus reduction and damping curves

In this study, a new p-y model is proposed for the seismic loading prediction of pile foundations using the Beam on Nonlinear Winkler Foundation (BNWF) method. It matches the desired modulus reduction curve by identifying three parameters in a hyperbolic function and a linear function using a genetic algorithm (GA), and the desired damping curve by applying the Ishihara-Yoshida rule that controls the unloading–reloading curves iteratively through the three parameters. The rate effect is integrated into the proposed PySimple5 model for clay by exerting influence on the ultimate capacity and maximum material damping through a power function, while the pore pressure effect is reflected in the proposed Pyliq5 model for sand by relating the ultimate capacity to the mean effective stress. For a single pile in non-liquefiable soil, the predicted superstructure acceleration and pile bending moment by PySimple5 agree well with those from centrifuge tests for different soil shear strain levels, while the equivalent linear and PySimple1 models underestimate them for soil shear strain levels higher than 1%. For a pile in liquefiable soil, PyLiq5 shows a reasonable agreement with the centrifuge tests in terms of the superstructure acceleration and pile bending moment by considering the pore pressure effect.

Three-dimensional numerical analyses of pile responses to tunneling-induced ground movements in bilayer soil

PurposeThis paper aims to investigate the responses of single piles and pile groups due to tunneling-induced ground movements in a two-layered soil system. The analyses mainly focus on the additional single pile responses in terms of bending moment, lateral deflection, axial force, shaft resistance and pile settlement. Subsequently, a series of parametric studies were carried out to better understand the responses of single piles induced by tunneling. To give further understanding regarding the pile groups, a 2 × 2 pile group with two different pile head conditions, namely, free and capped, was considered.Design/methodology/approachUsing the PLAXIS three-dimensional (3D) software, a full 3D numerical modeling is performed to investigate the effects of ground movements caused by tunneling on adjacent pile foundations. The numerical model was validated using centrifuge test data found in the literature. The relevance of the 3D model is also judged by comparison with the 2D plane strain model using the PLAXIS 2D code.FindingsThe numerical test results reveal that tunneling induces significant displacements and internal forces in nearby piles. The magnitude and distribution of internal forces depend mainly on the position of the pile toe relative to the tunnel depth and the distance between the pile and the vertical axis of the tunnel. As the volume loss increases from 1% to 3%, the apparent loss of pile capacity increases from 11% to 20%. By increasing the pile length from 0.5 to 1.5 times, the tunnel depth, the maximum pile settlement and lateral deflection decrease by about 63% and 18%, respectively. On the other hand, the maximum bending moment and axial load increase by about 7 and 13 times, respectively. When the pile is located at a distance of 2.5 times the tunnel diameter (Dt), the additional pile responses become insignificant. It was found that an increase in tunnel depth from 1.5Dt to 2.5Dt (with a pile length of 3Dt) increases the maximum lateral deflection by about 420%. Regarding the interaction between tunneling and group of piles, a positive group effect was observed with a significant reduction of the internal forces in rear piles. The maximum bending moment of the front piles was found to be higher than that of the rear piles by about 47%.Originality/valueSoil is a complex material that shows differently in primary loading, unloading and reloading with stress-dependent stiffness. This general behavior was not possibly being accounted for in simple elastic perfectly plastic Mohr–Coulomb model which is often used to predict the behavior of soils. Thus, in the present study, the more advanced hardening soil model with small-strain stiffness (HSsmall) is used to model the non-linear stress–strain soil behavior. Moreover, unlike previous studies THAT are usually based on the assumption that the soil is homogeneous and using numerical methods by decoupled loadings under plane strain conditions; in this study, the pile responses have been exhaustively investigated in a two-layered soil system using a fully coupled 3D numerical analysis that takes into account the real interactions between tunneling and pile foundations. The paper presents a distinctive set of findings and insights that provide valuable guidance for the design and construction of shield tunnels passing through pile foundations.

Experimental and numerical studies on the adjacent pile response to bucket spudcan penetration and extraction

ABSTRACT Jack-up rigs typically operate close to long-running jacket platforms. Unfortunately, penetration and extraction of the spudcan under jack-up rigs may impose an adverse influence on adjacent platform piles. In this study, the influence of bucket spudcan and inverted cone spudcan penetration and extraction on the lateral behaviour of adjacent pile were studied comparatively by conducting a series of model tests and numerical simulation in sand. The influence of spudcan-pile distance, pile diameter and pile head conditions on the spudcan-pile interaction were studied. Additionally, the soil flow patterns during penetration and extraction of two types of spudcans were analysed using the CEL. The results show that the pile bending moment and pile head displacement induced by bucket spudcan penetration and extraction are smaller than that of an inverted cone spudcan. It provides an engineering option for dealing with the adverse influence on adjacent piles induced by spudcan penetration and extraction.

Behavior of group piles under combined loadings after improvement of liquefiable soil with nanomaterials

Abstract Earthquake-induced liquefaction is prone in a region with loosely saturated sand and higher seismic activity. In recent years, improvement techniques have been used as a pre-construction or retrofitting method for the current construction. Several methods are intended as remedial techniques, which include either densifying the deposit soil, inserting a unique material, or controlling dissipated pore water pressure generated during the seismic motion. The permeation grouting technique is primarily used in remedial liquefaction schemes that aim to improve the soil deposit mainly by cementing the soil particles and filling the void spaces, thereby preventing soil disturbance caused by settlements or distress to an existing foundation or structure. Permeation grouting involves the injection of a low viscosity chemical or particulate grout into the soil pores with little to no change in the soil structure and has been shown to be effective at reducing liquefaction risk beneath existing structures in soils where it is applicable. The mitigation of liquefaction risk by incorporating nanomaterials using the permeation grouting technique, to study the performance of a pile group embedded in the liquefiable treated layer with 1/50 nano-clay and 1/30 nano-SiO2 after 48 h of curing time during the Kobe earthquake, has been adopted. The soil profile treated using nanomaterials showed that the soil stiffness and strength were preserved during shaking because it did not liquefy; simultaneously, the maximum pile bending moments and lateral pile displacements in the treated soil layer were reduced by 30%. Finally, after treatment, the nanomaterials have a significant effect on the reduction of the maximum accelerations in two depths of soil.

Integral bridge abutments in response to seasonal temperature changes: State of knowledge and recent advances

Expansion and contraction of integral abutment bridges due to temperature changes force integral bridge abutments (IBAs) to move toward and away from the backfill, thus increasing horizontal earth pressures behind the abutments and inducing bending moments on pile foundations. This paper presents the state of knowledge and recent advances in understanding the behavior of IBAs in response to temperature changes including abutment movement, pile response, and horizontal earth pressure behind the abutment, examines the effect of bridge skew on the behavior, and discusses possible measures to mitigate temperature change-induced problems for IBAs. Field data show that both bending moments of piles near the bottom of abutments and axial loads of piles fluctuated with temperature. Redistribution of dead loads among bridge components due to planar temperature gradients and earth pressure changes behind the abutment contributed to axial load fluctuations in piles. Magnitude and distribution of horizontal earth pressures behind the abutment depend on factors such as abutment movement and abutment movement mode. Most of the current design methods overestimated the horizontal earth pressures at the bottom of the abutment during bridge expansion. Compressible inclusions placed behind the abutment, geosynthetic-reinforced backfill, and lightweight backfill in place of typical aggregate backfill are helpful to reduce horizontal earth pressures behind the abutment at high temperatures and temperature change-induced backfill settlements.

Deformation and Force Analysis of Wood-Piled Island Cofferdam Based on Equivalent Bending Stiffness Principle

This paper analyses the deformation and force behavior of a wood-piled island cofferdam based on the principle of equivalent bending stiffness. The horizontal deformation and bending moments in wood piles and the axial stress in tension bars on top of piles were both analyzed by the finite difference (FD) method. Except for the analysis of the cofferdam construction process, the influence of the pile length, the dam width, the tension bar interval, and the pile interval, among the commonly adopted parameters, were detailly examined in numerical simulations. In addition, a reinforced wood-piled cofferdam model by steel pipe piles has been established to quantify the effect of reinforcement. It was found that the dewatering inside the cofferdam was detrimental to cofferdam stability. The pile deformation reached maxima (roughly 0.6% of the pile length) at solidifying stage after dewatering. The changing trend of the cofferdam structure force within a safe district was consistent with the displacement. The dam width had a vital effect on the stability of the cofferdam, especially on the horizontal deformation. The steel pipe pile reinforcement scheme performed better in further deformation control, providing a new idea for island-type cofferdams with rigorous structural deformation control.

Numerical Investigation of the Combined Influence of Shield Tunneling and Pile Cutting on Underpinning Piles

In this study, the combined influence of shield tunneling and the old pile cutting process on underpinning piles is investigated through finite element method (FEM) modeling based on a shield tunnel project in Nanchang Metro Line 2, China. Numerical models have been developed to analyze the influence of intersection angles and the vertical distance between the underpinning foundation and tunnels on the mechanical responses of underpinning piles during tunnel excavation. Simulation results show that the bending moment of the underpinning piles decreases with increasing vertical distance between the pile and tunnel, and is inversely proportional to the intersection angle between the underpinning beam and tunnel. In addition, the maximum pile bending moment occurs in the buried depth of the tunnel axis, indicating a high risk of damage in this part. According to the simulation results, more attention should be given to the underpinning piles in case a small vertical distance and intersection angle are encountered.

Dynamic interaction of coral sand-pile-superstructure during earthquakes: 3D numerical simulations

The seismic safety of piles and superstructures in coral sand deserves attention. To explore the particular dynamic interaction of the coral sand–pile-superstructure during earthquakes, fully nonlinear, 3 D numerical models were established using the Fast Lagrangian Analysis of Continuum (FLAC3D). Hysteresis damping was adopted to indicate the particular stress–strain relationship and shear modulus attenuation of coral sand. The results show that increasing the pile diameter reduces the superstructure settlement but amplifies the bending moment of the piles and superstructures. Specifically, when the pile radius increases from 0.05 m to 0.25 m, the superstructure settlement is reduced by 30.0%, while the moments of the piles and superstructures are increased by an average of 993.9% and 29.5%, respectively. Although the excess pore pressure ratio decreases when the coral sand permeability increases, the pile bending moment increases with an increase in permeability. Effectively balancing the superstructure settlement, pile bending moment and coral sand liquefaction should be considered in the earthquake resistance of coral sand.

Behavior of Mono Helical Pile Foundation in Clays under Combined Uplift and Lateral Loading Conditions

Offshore wind energy development is driven by ongoing research and development to determine technological issues connected with offshore wind turbines. A fundamental design difficulty is the offshore wind turbine foundations. By far, one of the most commonly practiced foundation systems is mono helical pile foundations because of their simplicity and resilience. Most of the studies on mono helical piles were focused on granular soils and few studies were on clayey soils. However, mono helical piles in clayey soils under combined loading remain to be examined. Hence, a series of three-dimensional finite element analyses were carried out to predict the uplift and lateral capacity of the helical pile embedded in soft clay. The numerical model is verified using the results from the analytical results and a small-scale laboratory test. The verified model is used to simulate the helical pile behavior under the combined uplift and lateral loading condition considering the pile with a different number of helical plates. The results of the combined loading analyses reveal that the lateral capacity decreased when the pile was subjected to uplift load, and a maximum reduction of 12% is observed in mono helical piles provided with a single plate for an applied 50% of the ultimate uplift load. The influence of uplift load also increased the bending moment of the helical pile. Finally, it is suggested that the helical piles should be designed considering the aspects for combined loading conditions.

Study on the Horizontal Bearing Characteristic of a New Type of Offshore Rubber Airbag Branch Pile

In this work, a new type of marine rubber airbag branch pile has been presented, and the influences of the exposed length L0 of the pile, size of rubber airbag branch and depth S0 of rubber airbag branch embedded in soil on the horizontal bearing capacity of the pile, have been investigated using numerical simulations. Simulation results were used to modify the eigenvalue equations of the horizontal bearing capacity. The results also showed that reverse displacement and the bending moment of the rubber airbag branch pile were lower in pipe piles with larger diameters, and the horizontal bearing capacity was more stable. At small horizontal displacements of the pile top, horizontal bearing capacities of large-diameter pipe piles were slightly higher, while for the pile’s top horizontal displacements of above 10 mm, horizontal bearing capacities of rubber airbag branch piles became significantly greater than those of the large-diameter pipe piles. Based on assumptions, the calculation equations of vacuum negative pressure and friction force between the rubber airbag branch and soil were derived. The equations for calculating the characteristic horizontal bearing capacities of rubber airbag branch piles were also derived and were modified based on simulation results. The calculation results confirmed the improvement in the accuracy of the modified equations.

Dynamic Response of Cement–Fly Ash Mixed Pile Composite Foundation Under Wave Load

CFMPs (cement and fly ash mixing piles) are used to reinforce fly ash foundation to solve the problem of a large amount of fly ash accumulation in coastal areas. CFMP-fly ash composite foundation is used as the foundation of coastal and coastal engineering. Through the indoor model test, the bearing characteristics and load transfer mechanism of CFMP-fly ash composite foundation under wave load were investigated. The results show that with the increase of wave load, the horizontal resistance of the fly ash stratum increases gradually, the soil resistance moves down, and the level of resistance shows nonlinear characteristics. The pile bending moment, pile displacement, and horizontal resistance of the CFMP composite foundation are concentrated in the upper pile and fly ash stratum, which can improve the ability of the composite foundation to resist horizontal load by improving the physical and mechanical properties of the upper fly ash stratum. Through the calculation of the load–displacement curve, it is found that the measured displacement value is closer to that obtained using the p–y curve method (a method for solving nonlinear lateral resistance of piles). The hysteretic curve area of cyclic loading decreases with the increase of cyclic number. The accumulation of elastoplastic deformation of pile shows that the properties of fly ash gradually change to elastic stage, cyclic loading can reduce the horizontal deformation modulus of composite foundation CFMP caused pile—fly ash system of weakening, in peak load reaches level under the critical state displacement curve showed a trend of the rapid growth of nonlinear, cyclic cumulative failure occurs, and the cyclic load limit state is reached, which affects the service performance of the whole structure.