膨胀土中加筋拉拔试验的影响因素分析

拉拔试验是研究筋、土界面相互作用的一种重要手段.然而,目前的试验设备与方法还无统一标准,测试结果常受到多种因素的影响.为弄清各主要因素的影响程度并提出合适的试验条件,以北京市西六环3种膨胀岩（土）为对象,采用长沙理工大学自主研究开发、先进的CS-LB01大型数控拉拔试验系统,通过改变上覆压力、填料含水率、拉拔速度、固结时间及加筋格栅类型等条件开展了系统拉拔试验,分析测试结果后得到各因素的影响及其规律.在此基础上,针对膨胀土堑坡实施土工格栅柔性支护特点,提出拉拔试验确定筋、土界面摩擦阻力的合适试验条件.

Analysis on influence factors of pullout test for expansive soil reinforced with geogrid

Pullout test is an important way to study on interface interaction between geogrid and soil. However, no uniform standard for pullout equipments and methods have been presented at home and abroad. In addition,the testing results are often influenced by many factors. In order to fully understand the main influence factors and put forward the appropriate testing conditions, a large-scale and advanced pullout test system ‘CS- LB01＇ developed by Changsha University of Science and Technology was utilized. Systematic pullout tests on three kinds of expansive soil under various conditions such as overburden pressure, moisture content, pullout rate, consolidation time and types of geogid were carried out. The influence of each factor on test results was obtained. Based on these results, the appropriate test conditions to determine the interface frictional resistance between geogrid and soil by pullout test were put forward for these features when expansive soil cutting slope was treated by flexible supporting treatment technology.