岩溶地区CFG桩复合地基现场试验研究

In-situ test on CFG composite foundation in karst area

CFG桩在地基处理中已得到越来越广泛的应用,针对岩溶地区某大型油炼厂地基处理的复杂性,基于标准贯入和重型动力触探试验结果,分析了CFG桩对桩间土的影响,以单桩和复合地基载荷试验验证了岩溶地区单桩及复合地基承载能力。此外,对CFG桩复合地基承载力进行了理论计算,并与现场试验进行对比分析。研究结果表明,CFG桩对桩间土没有明显的挤密效应;岩溶地区CFG桩复合地基承载力达到了设计要求。此外,利用试桩静载荷试验结果,并通过散点拟合,建立了承载力和桩长的经验计算公式。

CFG piles are widely used in foundation treatment engineering. Aiming to the complexity of foundation treatment of a large- scale refinery in karst area,the compacting effect of CFG piles on soils among piles was analyzed on the basis of the results of standard penetration test and heavy dynamic penetration test,and the bearing capacity of single pile and composite foundation was verified by static load test. Moreover,the bearing capacity of CFG composite foundation was checked by theoretical calculation and compared with in- situ test. The study results showed that the compaction effect on soil among piles by CFG pile was not obvious; and the bearing capacity of composite foundation in karst area can reach the standards. Based on the static load test results,an empirical formula between bearing capacity and pile- length is built by scatter fitting.