岩溶区桩基破坏模式研究及稳定性分析

在室内模型试验的基础上,采用有限差分法对桩基荷载作用下岩溶地基的稳定性进行数值模拟分析,得出溶洞周围岩体在桩基荷载作用下内部应力、应变的变化过程及破坏面的形状和位置等,提出判断岩溶区桩基稳定性的有效判据。归纳总结岩溶区桩基及其下伏溶洞的破坏机理和破坏模式,主要包括桩基破坏和溶洞围岩破坏。破坏模式主要受溶洞大小、荷载作用位置以及溶洞顶板厚度等因素影响,其中溶洞顶板厚度为主要影响因素。

FAILURE PATTERN STUDY AND STABILITY ANALYSIS OF PILE FOUNDATION IN KARST AREA

Based on the indoor model test,the stability analysis of the rock mass in karst area affected by pile was carried out by numerical simulation with the finite difference method.From the calculation results,it was obtained the changing procedure of the stress and the internal strain of the rock mass around the karst cave under pile load and the failure surface position,and put forward the effective stability criterion of the pile in karst area.It was also summarized the failure mode and failure mechanism of piles foundation in karst area,including pile foundation damage and the surrounding rock mass failure of the cave.The failure mode was mainly affected by the size of the karst cave,the load location,the roof thickness,and etc,in which the roof thickness was the main influence factors.