岩溶地区桩基竖向承载力的研究

依据大量的研究成果,分析了目前常用的研究方法和手段,主要包括室内实验室实验、现场静载荷实验、理论分析以及计算机数值模拟等,对岩溶地区桩基承载特性进行了分析和讨论,并对当前的相关规范作了分析评价,最后提出了自己的见解:1)在岩溶地区,当岩溶顶板安全厚度范围外存在溶洞时,可不考虑溶洞对桩基承载力的影响,单桩竖向极限承载力由桩周岩土总侧阻和嵌总端阻组成;2)当岩溶顶板安全厚度范围内存在溶洞或裂隙时,应考虑其对桩基承载力的不利影响,单桩竖向承载力可由摩擦力决定,且需要验算顶板的稳定性。

On Vertical Bearing Capability of Pile Foundation in Karst Area

Based on lots of research results,this paper analyzes the methods and means commonly used currently for determining the bearing capacity of pile foundation in karst area,mainly including in door test,site static load test,theoretical analysis and numerical simulation,etc.According to the analysis of bearing capability characteristics of pile foundation in karst area,and evaluation of related codes,the flowing conclusions are reached: 1) The vertical bearing capability of a pile in karst area depends on side friction and end block embed in rock when the karst cave is beyond the safety thickness,without necessity of considering the influence of karst cave on the bearing capacity;2) When the karst cave is within the safety thickness,the unfavorable influence of the cave shall be taken into account,and the vertical bearing capacity of a single pile is determined by the friction force.Moreover,the stability of top slab shall be checked.