土工格栅-粗粒土界面阻力特性的拉拔试验研究

Experimental Study on the Resistance Behavior of Geogrid-granular Soil Interface by Pull-out Tests

通过改变粗粒土料的级配、密实度和含水率等,对单向土工格栅进行了一系列的拉拔试验,以研究土工格栅在粗粒土中的拉拔破坏标准。结果表明,单向土工格栅在粗粒土中拉拔时,拉拔曲线通常表现出应变硬化的特征,拉拔力随拉拔位移增大而增大,没有峰值或稳定值,因此宜以容许拉拔位移作为拉拔破坏控制标准。经过对试验结果的分析和与理论值的比较,建议以土工格栅末端拉拔位移等于20 mm作为拉拔破坏标准。

By changing the gradation, density and moisture content of granular soil, a series of pull-out tests were carried out on uniaxial geogrids, and the pull-out failure criterion is discussed. It is proved by the test data that the pull-out curves usually are strain hardening. The pull-out resistance increases with the increase of the pull-out displacement without peak or stable value. Therefore, the allowable pull-out displacement should be taken as the failure criterion for the pull-out tests. Based on the analysis of the test results and the comparison of the theoretical values, it is suggested that the pull-out displacement at the end of geogrid equal to 20 mm be taken as the pull-out failure criteria.