固原309国道某路基边坡滑塌勘察分析

The Investigation and Analysis of a Slope Collapse of National Highway 309 in Guyuan

对宁夏309国道路基坍塌段进行现场勘察,取样进行含水率及强度试验,根据室内试验结果及岩性分布,分析坍塌原因,主要结论为:路基边坡土中含强风化软弱泥岩夹层,且厚度较大,粉质黏土与泥岩接触面上土体含水率大,抗剪强度较低,潜在滑动面位于下层粉质黏土与风化泥岩接触面,边坡含软弱夹层,且雨水下渗汇集夹层是造成路基边坡滑塌的主要因素。

In this paper, the site investigation of the collapse section of National Highway 309 is carried out. The water content and strength of the samples are tested, and the collapse cause is analyzed according to the laboratory test results and the lithologic distribution. The main conclusions are as follows: the slope soil of the roadbed contains strong weathered soft mudstone interlayer,and its thickness is large. The moisture content of the soil on the interface between silty clay and mudstone is large. The shear strength is low, and the potential sliding surface is located at the interface between the lower silty clay and weathered mudstone. The slope contains weak interlayer, and the infiltration and collection interlayer is the main factor which cause the roadbed slope to collapse.