土体水平位移对邻近既有桩基承载性状影响分析

城市建设中经常会遇到由于堆载或基坑开挖所引起的土体水平位移现象，土体水平位移的作用会使邻近建筑物的桩基础产生附加内力或变形，并可能导致邻近桩基的破坏而发生工程事故。针对此类问题，基于Winkler地基模型以及桩-土变形协调条件，建立单桩水平位移控制方程，根据内力与位移的微分关系，采用两阶段方法进行求解。结合典型的工程事故，通过参数分析，研究土体水平位移对邻近桩基承载性状的影响程度。分析表明，基坑工程围护墙体的稳定和开挖深度对邻近桩基的安全有着重要影响，并提出了近期发生在上海的某小高层楼房整体倒覆事故的一种可能原因。

Analysis of bearing capacity of a single pile under adjacent building subjected to lateral soil movements

Lateral soil movement due to surcharge loads and pit excavation often occurs in urban construction. The lateral soil movement may generate additional internal forces and deformation in pile foundation of adjacent buildings, and may lead to the damage of adjacent pile foundation and engineering accidents. Based on the Winkler’s foundation model and deformation compatibility condition of pile and soil, the horizontal displacement control equation of a single pile is established. According to the differential relations between the internal forces and displacements, the two-stage method is adopted to solve the equations. With the typical engineering accident, the influence of lateral soil movements on adjacent pile foundation is investigated by parametric analysis of the pile bearing capacity. The analysis shows that the stability of retaining wall and the excavation depth have an important impact on the safety of adjacent pile foundation. One of possible causes resulting in the collapse accident of a high-rise building in Shanghai is obtained from the analysis.