一、前言修建在软弱地基上的高层建筑物多采用桩箱式或带地下室的桩筏式基础。这类基础施工时,先将桩送下设计标高,再进行基坑开挖。常会在开挖基坑后发现桩已发生了倾斜甚至弯断。国内外已多次报道了这类事故,武汉市近几年也发生多起。虽然国内有关规范已制定相应条款,要求加强开挖基坑的防护,避免边坡失稳。但由于对软弱地基深开挖基坑下土的侧向流动和桩的受力机制重视不够,或未能严格按照规范要求组织施工,以致这类工程事故时有发生。 I. INTRODUCTION High-rise buildings built on weak foundations are mostly piled or boxed foundations with basements. In this type of foundation construction, the pile is first sent to the design elevation and excavated. After the excavation of the foundation pit, it was found that the pile had been inclined or even bent. There have been many reports of such accidents at home and abroad, and there have been many cases in Wuhan in recent years. Although relevant regulations have been formulated in China, it is required to strengthen the protection of excavation pits to avoid instability of the slope. However, due to the insufficient attention paid to the lateral flow of the deep excavation of the foundation pit and the stress mechanism of the pile, or failure to organize the construction in strict accordance with the requirements of the code, this type of engineering accident has occurred from time to time.