粉细砂的室内无填料振冲试验研究

在室内严格控制的边界条件下，通过室内模型试验研究了粉细砂无填料在振冲中孔隙水压力增长与消散的规律、孔隙水压力空间分布规律、相对密度和静力触探指标与振冲次数之间的关系等。定性地验证了无填料振冲对于规范中未推荐使用的粉细砂土的适应性，并为后来某工程大面积地基处理成功地提供了参考。

Laboratory test of vibroflotation on hydraulic backfilled silty and fine sand without backfill

The vibrofloation method without gravel backfill was only thought to be proper for treatment of medium and coarse sand with less than 10 % fine particles. Almost no project case available is concerning vibrofloation without backfill treatment of silty and fine sand. A laboratory test was then carried out to achieve the relating characteristics of the hydraulic silty and fine sand .In this test a reduced scale prototype model was set up, in which pressure gauges were embedded. From the data acquired during and after vibroflotation, the pore water pressure development and dissipation functions are established. The spatial distribution of pore pressure among soil was also studied. The cone penetration test(CPT) was made after each vibroflotation to discover the relationships among CPT, relative density and water pressure. Furthermore, the conclusions obtained from test were then used in guiding a ground improvement project in Shanghai.