Stress analysis of geosynthetic access mat systems over weak subgrade

Abstract

In pavement and/or geotechnical engineering applications, weak subgrade is usually pretreated by mechanical or chemical stabilization techniques to form a working platform or temporary roadway for access of traffics and construction equipment, such as trucks and cranes. A geosynthetic access mat (GAM) system can serve as an alternative to other mechanical or chemical subgrade stabilization techniques, especially for temporary load support. Due to its rigidity, the mat system can provide substantial vertical resistance to the applied load under a large deflection. However, no method is available to quantify the total vertical resistance and the stress at the top of the weak subgrade for design of this mat system. This paper adopted the plate theory for analyzing the vertical resistance from the GAM system and the vertical stress at the top of the subgrade. In the analysis, the deformation of the mat system was considered as the sum of two portions: the deformation of a large-deflection clamped-edge plate and the deformation of a small-deflection infinite plate on a Winkler foundation. The vertical resistance of the mat system estimated using this theoretical method was verified by numerical and test results. This verification confirms that the vertical resistance calculated based on the proposed theoretical method reasonably matches those numerical and test results.