双向土工格栅的蠕变与收缩特性研究

Study on the Creep and Shrinkage Properties of Bidirectional Geogrid

对两种型号的聚丙烯(PP)双向土工格栅进行相同应力水平条件下的蠕变试验,试验结束后完全卸载并对其收缩情况进行观测。试验结果表明,在蠕变过程中,双向土工格栅试样各部分蠕变发展并不均匀,最终的应变值为4%~5%,与单向土工格栅相比双向土工格栅蠕变速率发展较慢。采用开尔文串联模型对格栅收缩试验过程进行模拟,建立了描述土工格栅粘弹塑性收缩变形的数学方程,并对试验结果进行了拟合,拟合效果良好。

In this paper,the 1000 hcreep tests were conducted on two kinds of polypropylene bidirectional geogrid under a same stress level.The shrinkage measure ment was done after the creep tests and complete unloading.The test results show that,in the process of the creep,the development of is creep for the geogrid specimens is nonuniform,and the final strain of bidirectional geogrid is about 4%~5%,which is less than that of uniaxial geogrid.On the other hand,by using the Kelvin model and other models to simulate the process of the shrinkage tests,an equation was established to describe the shrinkage of the geogrid.The experimental data were fitted with the equation and the result is good.