湿陷性黄土地基侧向防渗结构模型试验研究

MODEL EXPERIMENTAL RESEARCH ON STRUCTURE OF LATERAL SEEPAGE CONTROL IN COLLAPSIBLE LOESS FOUNDATION

水分对于湿陷性黄土地基具有重要影响。本文通过室内土工试验,得到兰州黄土和灰土的物理力学参数;并通过室内模型试验研究了不同侧向防渗结构对于路基的侧向防渗效果;同时对路基进行了沉降监测。试验结果表明:灰土的渗透系数远小于黄土的渗透系数;经过灰土挤密桩和灰土防渗墙处理的工况,其土中含水量远小于不作侧向防渗处理的情况,且路基的湿陷变形情况明显改善。其中灰土防渗墙的防渗效果比灰土挤密桩的更好。试验结果可有效地指导湿陷性黄土路基的防渗处理,为湿陷性黄土地基处理提供新的思路。

Water plays a pivotal role in influencing collapsible loess foundation. In this article,the physical and mechanical parameters of loess and lime soil in Lanzhou are obtained through indoor geotechnical test. The effect of different structures to control lateral seepage in subgrade loess soil is studied through indoor model test. At the same time,the settlement of roadbed is monitored. The experimental results reveal that the permeability coefficient of the lime soil is much less than the coefficient of permeability of loess. After processed by lime-soil compaction pile and lime-soil impervious wall,the moisture content of loess is far less than the value that the lateral seepage control processing is not made. Collapsibility deformation of subgrade is obviously improved. The effect of lime-soil impervious wall is better than the lime-soil compaction pile. The test results can guide the collapsible loess subgrade seepage prevention effectively,and provide a new idea for collapsible loess foundation treatment.