Probabilistic Tensile Strength Analysis of Steel Strips in MSE Walls Considering Corrosion

Abstract

Design for the tensile strength limit state of steel strip reinforcement in mechanically stabilized earth (MSE) walls must provide for loss of steel thickness due to corrosion. The paper combined key features of zinc and steel corrosion models found in the literature with corrosion rate statistics for buried galvanized steel strips. Examples of loss of strength of reinforcement strips of different thickness for up to 120 years after construction were presented in probabilistic terms. Results of probabilistic analysis for the tensile strength limit state at a design life of 75 years were demonstrated for a typical wall using three different models to compute the maximum tensile load in a strip under operational conditions. The same three models were used to demonstrate a methodology for load and resistance factor design (LRFD) calibration for the tensile strength limit state for steel reinforcement strips. The calculations showed that the accuracy of the load model with respect to measured loads has a strong influence on the magnitude of computed resistance factor for a prescribed load factor and maximum target level of reliability.