Experimental and Analytical Evaluations of Mechanically-Stabilized Layers with Geogrid over Weak Subgrade under Static Loading

摘要

Mechanically-stabilized layer (MSL) with multi-axial geogrid is an effective ground improvement technique that helps to increase bearing capacity and reduce settlement of soil foundations, and increase strength/stiffness of geo-materials. The MSL with geogrid is frequently used for construction platform and foundation applications subjected to static loading. Load distribution in the MSL under static loading is a basic load transfer mechanism. To further investigate the load transfer mechanism, four large-scale plate loading tests were conducted on 300-mm thick MSLs over weak subgrade under static loading. The subgrade had an undrained shear strength of approximately 48 kPa. Three static plate loading tests were performed on the MSLs with three types of multi-axial geogrids. A non-stabilized but similar section was also tested as a control section. During each test, a load was applied at a constant displacement rate until failure. From the load-displacement curves, the ultimate bearing capacities of the test sections at similar displacements were determined. The test results show that the MSL with the geogrid increased the bearing capacity and stiffness of the test section. The benefit of the geogrid to the increased bearing capacity measured experimentally was compared with the established analytical formulae developed by researchers.