EVALUATION OF INDUCED LATERAL STRESSES FROM NOISE WALL LOADING ONTO FLEXIBLE RETAINING WALLS

Abstract

While the effects of uniform vertical surcharges have been studied extensively (e.g., Spangler 1956; Jarquio 1981; Georgiadis and Anagnostopoulos 1998; Greco 2006), the induced lateral pressures from horizontal (shearing) surcharge and non-uniform vertical surcharges is largely unknown. Past researchers (e.g., Steenfelt and Hansen 1983; Georgiadis and Anagnostopoulos 1998) have both analytically and experimentally found that plastic limit equilibrium solutions best predict these induced lateral pressures. Based on the success of plastic solutions predicting the response of retaining walls under uniform vertical surcharge loading, a modified limit equilibrium methodology was proposed to quantify the pressures from horizontal surcharge and non-uniform vertical surcharges. To validate this proposed methodology, a small-scale experimental model is constructed and tested. The experimental testing program included varying distances from the applied surcharge to the retaining wall and varying the magnitudes of these horizontal and vertical surcharges. Results revealed that smaller distances, 𝑑𝑑, between the surcharge and the retaining walls and larger surcharge magnitudes, 𝑞𝑞ℎ and 𝑞𝑞𝑣𝑣𝑣𝑣, result in higher bending moments due to higher lateral pressures. The experimental results were then compared with predictions from the proposed plastic solution, a solution based on elasticity theory, and an approximate method discussed in Berg et al. (2009) based on the AASHTO LRFD Bridge Design manual. The proposed plastic model was found to be the most accurate method of predicting the bending moment response of induced stresses from the noise wall surcharge loading for both small and large values of 𝑑𝑑. Ultimately, the values of 𝑑𝑑, 𝑞𝑞ℎ, 𝑞𝑞𝑣𝑣𝑣𝑣, and 𝜙𝜙 (friction angle of backfill soil) were determined to control the threshold of whether a surcharge will affect a cantilever retaining wall.