Analysis of Reinforced Soil Wall Considering Oblique Pullout of Reinforcement Resting on Two-Parameter Pasternak Subgrade

Abstract

Conventional methods of analysis and design of reinforced soil walls consider only axial direction of the pullout force and do not consider complex soil- reinforcement interaction and obliquity of the pullout force. However, kinematics of failure of the walls suggests that the failure surface intersects the reinforcement obliquely thus causing an oblique pullout of the reinforcement. Consequently, the reinforcement deforms downward and mobilizes additional normal and shear stresses at the soil-reinforcement interface. Thus, the pullout capacity of the reinforcement may be considerably different compared to the axial one. In this paper, a new analysis is presented for the design of reinforced soil walls considering that the reinforcement is subjected to an oblique pullout force and resting on a two-parameter Pasternak subgrade. The contribution of shear stiffness of the subgrade has been incorporated in the analysis by assuming a Pasternak shear layer resting on a set of Winkler's springs. Thus, use of Pasternak model as subgrade makes the analysis more realistic. A modified factor of safety is defined, evaluated, and compared with the conventional one to establish the suitability and applicability of the present analysis in the design of reinforced soil walls. A parametric study is also conducted to study the effect of various geometrical and material properties on the stability of reinforced soil walls.