真空预压法加固软土地基的效果观测分析

真空预压法是加固软土地基的有效方法。本文以实际工程为例,详细论述了真空预压设备的布设,施工方法,检测方法及检测仪器的布设,对工程实际的观测结果进行了深入分析。实践证明使用真空预压法,通常对地基施加相当于80kPa荷载的真空压力,100d后地基的总沉降量可达到1m,地基土的平均固结度超过90%。经过加固的地基抗剪强度明显增加,含水量和孔隙水压力明显减小,地基的承载力可达到80kPa以上。

Case study on consolidation of soft foundation by means of vacuum preloading

Vacuum preloading is an effective technology for consolidating soft foundation. The successful application of this technology to a highway project is presented. The vacuum pressure of 80kpa is applied for 90 days to consolidate the soft clay layer with thickness of 20m. The settlement is about 1.5m. The average degree of consolidation estimated according to the observation data is about 90%. The undrained shear strength of the soil is elevated and the water content and pore water pressure are remarkably reduced after vacuum preloading. The bearing capacity of the foundation reaches 80kpa. The procedure of implementation and the in situ monitoring data are introduced in detailed.