CFG桩复合地基桩土应力现场测试与数值模拟  

Numerical Simulation and Field Testing on Pile-soil Stress of CFG-pile Composite Foundation

作　　者：徐继欣[1] 张鸿[2] 周院芳 陈书全 

机构地区：[1]安徽省公路工程检测中心,安徽合肥230022 [2]南昌工程学院土建学院,江西南昌330099 [3]江西公路开发总公司,江西南昌330038

出　　处：《施工技术（下半月）》2012年第4期84-87,共4页Construction Technology

基　　金：江西省科技支撑计划项目(2010BGB01302);江西省交通运输厅重点科技项目(2010C00013;2010C00014)

摘　　要：针对复合地基在路堤荷载下与刚性基础下受力结构模式存在一定的差异,对江西某高速公路软基试验段填砂路堤下CFG桩复合地基承载力特性进行了现场试验,同时采用有限元差分软件FLAC3D建立模型,对复合地基桩土应力与土体沉降进行了数值仿真计算。结果表明,静载试验测试桩间距1.5m的桩土应力比为5.58,与实际路堤加载监测值2.26和数值计算值2.72有一定的误差。因此,对于本工程仅采用静载试验确定路堤荷载下CFG桩复合地基承载力是不合适的。Aiming at certain differences of stress structure modes of the composite foundation that under embankment load and under rigid foundation,a field test has been conducted on the bearing capacity features of a CFG-pile composite foundation for the sand-filled road embankment of a soft roadbed for a certain expressway.The finite difference software named FLAC3D is adopted to build the mathematical model and to conduct a numerical simulation and calculation of the pile-earth stress of the composite foundation and the sedimentation of the earth.The test results show that when the distance between tested piles in the static load test is 1.5 m,the pile-earth stress ratio is 5.58,which is significantly higher than 2.26 as actual monitored values when the road embankment is under load on by and 2.72 as the calculated value.Therefore,determining the bearing capacity of a CFG-pile composite foundation for a road embankment under load only using the static load experiment is inappropriate.

关 键 词：地基 CFG桩 柔性荷载 现场测试 数值分析 桩土应力比 

分 类 号：TU413.4[建筑科学—岩土工程]