Localized shear strength mobilization at geosynthetic interfaces caused by spreading soil upslope

¹ Thiel Engineering, Oregon House, CA, USA
² Consulting Engineer, Paris, France

^* Corresponding author: richard@rthiel.com

Abstract

Localized interface shear strength failures have occurred during placement and spreading of cover soils on top of geosynthetic layers on slopes using construction equipment, typically bulldozers (‘dozers’). The mechanisms of these types of failures are rarely considered and evaluated in design reports and calculations. The present paper intends to improve upon the analyses presented in previous literature references by providing straightforward equations of static equilibrium that the user can easily input into a spreadsheet to model various dozer sizes, geometries, and shear strengths. The present paper analyzes the shear forces below the soil pile being pushed, as well as below the dozer tracks, which has not been previously considered in the available literature. The equations provided in the present paper should be useful for design engineers to avoid slippage on slopes where dozers are spreading soil materials over geosynthetics, or for forensic experts who evaluate why slippage may have occurred.