振冲法加固松软土地基能力分析

Ability of strengthening soft soil foundation by vibroflotation method

针对松散砂土、粉土、黏性土等软土地基,研究提高地基承载能力和减少沉降的措施。振冲挤密法适用于松散砂土层;振冲碎石桩适用于处理粉土和一般黏性土及软黏土(淤泥、淤泥质土);振冲粉喷碎石桩适用于粉土和黏性土层(不排水抗剪强度c u>15 kPa)。介绍振冲粉喷碎石桩的制备材料配合比,通过试验得到立方体抗压强度,在施工中可采用干法底部出料工艺。结果表明,振冲粉喷碎石桩较振冲碎石桩在同等设计条件下可提高地基承载力约1.3倍,并减少地基沉降,具有广阔的市场前景。

For soft soil foundation such as loose sand,silt and clay,we study the measures to improve the bearing capacity and reduce the settlement.The usable soil layer of vibro-compaction method is loose sand.The vibro-replacement stone column method is used to treat silt,general clay and soft clay(silt,silty soil).The usable soil layers of vibro-powder sprayed stone column are silt and clays(the undrained shear strength c u>15 kPa).We introduce the material mix ratio of vibro-powder sprayed stone column,obtain the cube compressive strength through test,and use dry bottom discharging technology in construction.The results show that compared with vibro-replacement stone column,vibro-powder sprayed stone column can increase the bearing capacity of the foundation by about 1.3 times and reduce the settlement of the foundation,which has a broad market prospect.