沉桩对邻近既有桩内力变形的影响分析

Analysis of Effects of Pile Driving on Lateral Soil Movement of Adjacent Driven Pile

基于布辛奈斯克位移解与p-y曲线法,求解沉桩引起的自由土体水平位移并建立了单桩水平位移控制方程,采用两阶段法研究了沉桩引起的既有桩响应,分析了既有桩桩顶约束条件、桩身刚度及土体强度对既有桩性状的影响。研究表明,沉桩初始阶段在邻近既有桩中产生较大的桩身弯矩,沉桩深度增大时,既有桩桩身弯矩减小。既有桩桩顶约束条件对桩身性状有明显影响。土体强度增大时,既有桩桩身弯矩与变形均增大。既有桩桩身刚度增大时,桩身位移减小,桩身弯矩增大。

Based on Boussinesq＇s deformation formula and p- y curve method,the horizontal displacement of pile driving is solved and the horizontal displacement control equation of a single pile is established. The response of the driven pile due to pile driving is studied by a two- stage method and the effects of pile head constraint,pile bending stiffness and soil strength on the response of pile are analyzed. The analysis results indicate that pile driving has a larger effect on adjacent pile at the beginning of driving. The bending moment in the driven pile decreases with the increasing in the driving depth. The constraint conditions of pile top have a significant effect on the behavior of pile. The bending moment and deformation of the driven pile increase as the soil strength increases. The displacement decreases and bending moment increases with the increasing in pile bending stiffness. Key words： pile driving; driven pile; lateral soil displacement; two- stage method