Effect of Subgrade Condition on the Performance of Geosynthetic Composite Liners
Geosynthetics were widely used in landfills, espcially in the United States and European countries. The objective of this research is to study the effect of subgrade condition on the performance of geosynthetic composite liner composed of geomembrane (GM) and geosynthetic clay liner (GCL). Laboratory permeation tests were performed to measure the flowrate of water through the composite liner with holes in the GM. After each test, the thickness and mass per unit area of the GCL specimen was measured in a number of locations to determine the variation of distribution of bentonite. The results show that the flow rate through the composite liner decrease with increasing confining stress in general. However, there were two instances where the GCL specimens got punched by the crushed-stone subgrade, such that the flowrate was significantly higher. Furthermore, it was found that the distribution of bentonite was more uniform for GCLs in contact with subgrade of smaller size particles.
|Appears in Collections:||Thesis|