Influence of filling properties and culvert structure parameters on the soil arching effect of upper-buried-type culverts

Abstract

A high fill load may lead to several defects in culvert structures. Therefore, it is necessary to accurately calculate the earth pressure at the top of a culvert and the coefficient of earth pressure in fillings. In this paper, a numerical model is proposed to accurately calculate the earth pressure at the top of upper-buried culverts and the coefficient of earth pressure in the filling. First, indoor model tests were used to determine the earth pressure at the top of a culvert at different filling heights, and the theoretical soil arch coefficient calculation equation derived. Then, the numerical model was calibrated and its accuracy verified by comparing experimental and numerical simulation results. The effects of filling height, rock block proportion, filling Poisson's ratio, and slab thickness on the top and sides of the culvert were also analyzed. The results show that all factors will affect the earth pressure at the top and sides of the culvert. Further, the vertical earth pressure is parabolic on the top of the culvert, which can be explained by the shear lag effect of a symmetrical cantilever hollow box girder. The results of this study can be used as a reference for optimum design of culverts with high filling, and to reduce the occurrence of culvert accidents.