Load and Resistance Factors for Internal Stability Checks of Mechanically Stabilized Earth Walls

Abstract

This paper focuses on the development of load and resistance factor design (LRFD) for checks of the internal stability of mechanically stabilized earth (MSE) walls reinforced with steel strips. The internal stability of MSE walls relies on protection against two ultimate limit states (ULSs): pullout and structural failure of reinforcements. This study proposes equations for the resistances and loads that reflect the physical processes involved in the pullout and structural failure ULSs and quantify the uncertainties in these equations. These equations are then used to perform reliability analyses using the first-order reliability method (FORM) for different values of target reliability index to obtain load factors and resistance factors for use together with the equations in design. For a given target reliability index and vehicular load on top of an MSE wall, the resistance factor for pullout was highly dependent on reinforcement depth while that for structural failure was insensitive to changes in the design variables in its ULS equation.