Research On Numerical Simulation Of The Bearing Performance Of Large Bridge Pile Foundation Of Wujiang Bank Slope

In order to solve the shortage of land resources caused by the explosive growth population, construction began to develop in the direction of enlarged. Based on the needs of strategic development at the same time, some important national highway and bridge engineering have to be constructed in the dangerous natural environment, which would result in the higher requirement for the bearing capacity of building and bridge pile foundations. The existing traditional static load test in situ is difficult to measure the bearing capacity of the oversize pile foundation accurately. Also, due to the imperfect development of theories and the increasingly complex engineering challenges, all test methods still have some defects and shortcomings. Limited to special landform condition of western mountainous area of China, many road and bridge constructions can only be built up on the mountain, through viaduct or half road and half bridge structure. This makes part of the pile foundation construction the slope or even dangerous broke back cliff. For in the slope above the load-bearing characteristics of pile foundation and pile foundation engineering research on the influence of slope stability analysis is relatively small, there is no relevant industry standards and the unified formula can consult.Traditional numerical method has achieved great development thanks to the rapid improvement of computer performance and the continuous improvement of programming techniques. In this paper, combined with the engineering project survey, and through the test to get the general situation of the project, stratigraphic and lithological and other basic information. Using FLAC3 D software platform to build a three-dimensional numerical simulation model. Combined with the actual geographical environment and the force condition to analyze the stress and deformation of the bridge foundation under combined loading condition. Through the study of theory of strength reduction method, the calculated safety factor, in order to evaluate the slope stability, Finally, using FLAC3 D dynamic analysis module to analysis the bridge foundation and the slope under seismic load dynamic response. Conclusions can be gained as follows:(1) Using strength subtraction obtained safety factor after the completion of the construction, the result is 2.59. The bridge engineering construction did not cause too big effect on the stability of bank slope as a whole, bank slope is still in the stable state.(2) The dominant part of pile foundation under vertical load, so the vertical displacement is bigger than horizontal displacement, the maximum vertical displacement and horizontal displacement of the model are in direct charge of pile caps.(3) Under combined loading condition, pile foundation did not reach ultimate bearing state. The vertical displacement and horizontal displacement of pile foundation diminishes with pile depth. There is an obvious flexural deformation of pile body. There is a significant difference for axis force at different position. The axis force for corner pile is significantly larger than for side pile.(4) Under seismic load, the speed of the monitoring process curve variation agrees with the input of seismic wave velocity time history curve, the slope of input seismic wave has vertical amplifier and airport surface amplification effect.