Modeling Drilled Shafts in MSE Block Walls

Abstract

Mechanically stabilized earth (MSE) technology is recognized for its efficiency for constructing earth retention structures. In some cases structural foundations must pass through the reinforced fill due to the required footprint of the reinforced zone behind the facing. Limited information about the interaction between the structure and the MSE mass has been published, making efficient design difficult. It is very costly to construct and test all possible geometries or applications; therefore numerical modeling must be used to supplement physical data. This thesis contains a discussion of the analysis of physical test data and numerical modeling of an MSE test wall containing foundation elements. The test wall consists of an MSE wall with cast-in-place shafts contained within and solely supported by the reinforced fill. The finite difference numerical modeling program FLAC3D was used for analysis. A parametric study was conducted to determine how the various constituents of the physical wall as well as wall height affect wall - shaft behavior. Analysis of the modeling results were then used to create design recommendations for MSE walls with foundation elements. Geogrid was found to be the greatest influence on behavior. Wall height has a large influence on capacity at shaft movement of more than 2 inches.