Three-dimensional stability analysis of the collapse pressure on flexible pavements over rectangular trapdoors

Abstract

Abstract A hole in a flexible pavement is commonly formed due to several environmental impacts. With a continued overload traffic action, a collapse of the hole over the flexible pavement can potentially occur resulting in a pothole on a road surface. Solutions of trapdoor problems are useful for predicting the failure of the hole taking place below the flexible pavement subjected to the overload traffic. In this paper, the collapse pressure on flexible pavements over rectangular trapdoors in homogeneous clay is investigated by a three-dimensional lower bound finite element limit analysis using semidefinite programming. Results of the present study are verified against the existing solutions for the cases of plane strain trapdoors. New lower bound solutions of the problem are numerically derived as functions of cover-depth ratios and aspect ratios of rectangular trapdoors while associated failure mechanisms are discussed and compared. Approximate algebraic equations for stability numbers of rectangular trapdoors are also presented.