CFG桩处理风积砂土地基承载性状研究

Study on the bearing properties of aeolian sand foundation treated with CFG piles

以CFG桩(cement fly-ash gravel pile)处理榆林地区风积砂土地基为例,用有限差分软件FLAC3D模拟了CFG单桩、复合地基的承载性状,与现场载荷试验吻合较好;分析了不同桩体截面、褥垫层参数及桩长等因素对单桩及复合地基承载性状的影响。结果表明:合理的褥垫层厚度对桩土应力比调节作用显著,CFG桩复合地基存在临界桩长,单桩摩擦桩的性状明显,且现有理论计算结果偏于安全;CFG桩复合地基能有效优化风积砂土的承载力性状,从而使风积砂土承载力提高。

The bearing properties of CFG pile(cement fly-ash gravel pile)and composite foundation were studied using finite difference software FLAC3 Dbased on the CFG pile treated foundation in Yulin.The results agree well with in-situ load tests.The influence of single pile and composite foundation load-bearing properties under different pile cross section,cushion parameter sand pile length were analyzed.The results showed that the thickness of cushion layer has a significant influence on the stress ratio of pile-soil.The CFG pile has a critical length as a friction type pile.The theory results were conservative.CFG pile composite foundation can enhance the bearing capacity by optimizing the properties of wind-blown sandy soil.