振动碾压在超大厚度换填软弱层地基处理中的研究与实践

Study and Practice of Vibroroller Compaction in Large Thickness Cushion for Ground Treatment

结合电厂工程,对超大厚度软弱层换填振动碾压法的适用性进行试验研究。通过现场平板载荷试验和地表沉降观测进行质量控制。结果表明:①换填采用级配良好的砂卵石,换填厚度400mm,振动碾压6～8遍,不至产生剪胀;②换填场地地基土承载力特征值均大于500kPa,变形模量大于150MPa,承压板沉降量平均值1.75mm,满足设计要求;③截至2007年10月10日,各观测点的累计沉降量15.7～20.2mm,平均值18.128mm,满足设计要求;④换填振动碾压法对超大厚度软弱层地基处理具有良好的效果,在同类方案中更趋经济合理,具有推广价值。

The vibroroller compaction method in large thickness cushion is tested and studied in certain power plant engineering in this paper. And quality control is conducted by in-situ plate load test and settlement observation. The results show that： （1）The well graded sand and gravel is used as cushion, of which the thickness is 400mm. And the times of vibroroller compaction is 6-8. At this rate the possibility of shearing expansion is small; （2）The bearing capacity eigenvalue of foundation soil with cushion is more than 500kPa, the deformation modulus is more than 150MPa, and the average settlement of load-bearing plate is 1.75mm, which all meet the design requirement; （3）Until October 10th 2007, the total settlement of all observation points is between 15.7mm and 20.2mm, and the average is 18.128mm, which meet the design requirement; （4）The vibroroller compaction in large thickness cushion for ground treatment of weak layer has good results. In similar schemes, this approach is more economic and reasonable, which has great popularized worth.