岩溶地区基础选型分析和工程应用

Analysis and engineering application of foundation selection in Karst Area

岩溶地区地基处理是工程建设中普遍存在的难题,基础形式的选择需考虑建筑特点、结构安全、施工技术条件及经济性。在规范的基础上总结了岩溶地区基础设计基本原则,针对多层及小高层建筑提出了基础尽量浅埋的设计思路,对于高层建筑主张采用整体性好,刚度大的桩筏基础,避免个别桩基因桩端存在溶洞、裂隙等未发现时对上部结构带来安全隐患。通过工程实践验证笔者的设计思路,一是介绍了工业重载厂房中利用强夯法发现和破坏浅层溶洞,开创了强夯处理浅层土洞的先例,避免了个别溶洞未发现时造成安全隐患;二是桩基设计时采用穿透能力强的冲孔灌注桩,基础形式为桩筏基础,通过多年使用后的实际效果说明溶洞处理措施是恰当的,在安全性和经济性两方面均取得了良好的效果。

Foundation treatment in karst areas is a common problem in engineering construction.The choice of foundation form needs to consider building characteristics,structural safety,construction technical conditions and economy.This paper summarizes the basic principles of foundation design in karst areas on the basis of the specification,and proposes a design idea of burying the foundation as shallow as possible for multi-storey and small high-rise buildings.If there are karst caves and fissures at the end of the pile,it will bring security risks to the superstructure if it is not found.The author’s design ideas are verified through engineering practice.First,the use of dynamic compaction in industrial heavy-duty workshops to discover and destroy shallow karst caves has created a precedent for the treatment of shallow soil caves by dynamic compaction,avoiding the safety of individual karst caves when they are not found.hidden danger;Second,the punching cast-in-place pile with strong penetration capacity is adopted in the pile foundation design,and the foundation form is pile raft foundation.The actual effect after many years of use shows that the karst cave treatment measures are appropriate,and good results have been achieved in both safety and economy.