深基坑内基础工程桩对软土强度影响试验分析

从南宁某工程实例观察到的现象出发,分析了勘察期与基坑、基础工程施工期对软土性质的影响因素,认为勘察期的钻探工艺、试验方法等通过对软弱土结构的损伤对土进行扰动,且扰动程度比较大,弱化了软土的力学性质,而施工期的降水开挖及基础工程桩设置增强了软土的力学性能。并结合具体工程对基础桩基设置对软土的效应进行了三点载荷试验研究,试验结果与上述分析一致。从现象与试验两个角度说明:南宁工程界对软土特性与利用还有待于研究。

Effect of piles in deep pits on strength of soft soil

Form the phenomena of an engineering case,factors were analyzed to affect properties of soft soils during site investigation and deep pit excavation processes.Methods of drilling borehole and laboratory test disturbed structures of soft soils,and the strength of soft soils was depressed.While the strength of soft soils was increased after driving piles and excavation with the groundwater drop during construction.Three static plate loading tests were finished on soft soil ground.The test results are in agreement with the above analysis.From the engineering case and field tests,soft soils in Nanning should be particularly studied by engineers.