深层搅拌法在真空预压后地基工程上的应用

Application of cement deep mixing method to foundation improved by vacuum preloading

为使经真空预压首期加固后的地基承载力从80kPa提高到230kPa,设计采用深层搅拌法—水泥搅拌桩二次加固软弱地基。经现场成桩工艺试验和检测表明,桩身水泥土强度在90d龄期时>1.80MPa,单桩承载力标准值>150kN;以!600桩径、桩长13.5m、置换率为0.308和!500桩径、桩长13.5m、置换率为0.267两种方案布置的复合地基承载力标准值均超过了设计要求。

The bearing capacity of foundation improved by vacuum preloading was 80 kPa. The cement deep mixing method was applied to improve the foundation bearing capacity increased to 230 kPa. The in-situtest indicates that the pile shaft strength in the time of 90 days is greater than that in 1.8 MPa, and the single pile bearing capacity is greater than 150 kN. Meanwhile, the composite foundation standard bearing capacity for two pile layout schemes is greater than that of the design specifications.