岩溶地区嵌岩桩安全性理论分析与应用

在岩溶地区进行嵌岩桩设计时，应选择具有一定安全厚度的基岩作持力层。基于溶洞顶板均质、各项同性等基本假定，根据桩端直径与桩底溶洞大小、类型，模拟外荷载作用下混凝土板受力变形破坏特征，并对溶洞基岩顶板进行简化分析，得到各种状况下的岩溶顶板安全厚度与桩端应力值、岩石单轴抗压强度、溶洞类型与大小等相关数学表达式。该式简单、直观，较全面反映了影响溶洞顶板安全厚度的各种因素，并得到实际工程验证。

Theoretical Analysis and Application of Socketed Pile Safety in Karst Area

In karst area,base rock of a certain safe thickness shall be applied in the design of socketed pile as the supporting layer.Based on the basic assumption of karst roof homogeneity and isotropy,according to pile tip diameter and bottom cavern size and type,this paper simulates concrete slab stress deformation characteristicsunder external load and carries out analysis on the simplification of cavern rock roof.It gets the relevant mathematic expression of the relationship between karst roof safe thickness and pile tip stress,rock uniaxial compressive strength,cavern type and size under different conditions.This expression is simple and direct,which fully reflects various influence factors of karst roof safe thickness and has been validated in practical engineering.