Seismic Performance Analysis Of Row Pile Supporting Structure And Its Supporting System

With the rapid development of social economy,urban rail transit project is in the ascendant,and the foundation pit project of new road will inevitably be adjacent to high-rise buildings.The characteristic of pile row supporting structure is that it has high rigidity and does not need to erect inner support and back anchor.It solves the problem of insufficient site behind pile and is widely used in the design of urban foundation pit.However,under the earthquake,the instability of the road foundation pit support structure brings a huge threat to the safety and stability of the adjacent traffic engineering and buildings.It is of great significance to study the seismic performance of buildings and their supporting structures adjacent to foundation pit excavation under earthquake.In this paper,the three-dimensional finite element software ABAQUS is used to analyze the influence of foundation pit excavation on the seismic performance of the supporting structure system of the adjacent bone ash tower.By applying 0.2g horizontal one-way seismic wave to the bottom of the model,the dynamic characteristics and displacement changes of the row pile support structure are studied,with the emphasis on the analysis of the overall lateral displacement of the support pile and the displacement time history curve of the top of the support pile;Based on the numerical model,through the parametric analysis of seismic wave type,seismic wave amplitude value,pile distance,pile length,elastic modulus of pile and other factors,the influence of pile and soil parameters on the displacement,bending moment and dynamic earth pressure of supporting pile is systematically analyzed;Using the numerical model,the influence of supporting structure on the horizontal displacement and vertical displacement of the ash tower is compared and analyzed,and the seismic performance changes of the ash tower before and after the support near the foundation pit excavation are explored.The results show that: the lateral displacement of the pile supporting structure increases sharply in 5s≤t≤30s,and the horizontal displacement of the back soil side exceeds 0.3m,and then it is destroyed;The "soil arching effect" produced by the soil behind the pile can reduce the lateral displacement of the pile and improve its resistance when the distance between the piles is reasonable;In a certain range,increasing the pile length can significantly reduce the displacement of the pile body.When the embedded depth is more than half of the pile length,the influence of the pile length on the lateral displacement of the pile body becomes smaller;The maximum horizontal displacement of the ash tower under small earthquake is 2.27 mm less than that before support,and the maximum horizontal displacement under large earthquake is22.63 mm less than that before support.The support structure effectively improves the seismic performance of the ash tower.