Calculation of earth pressure on culvert underlying flexible subgrade

Abstract

Abstract To explore the influence of soil displacement around culvert on earth pressure at culvert crown, the concept of “neutral point” of culvert is proposed based on the interaction mechanism of culvert-fill-subgrade. Based on the calculation of subgrade settlement by elastic theory, the theoretical formula for calculating earth pressure of culvert with high embankment fill is deduced. The results of numerical simulation method, neutral point method proposed in this paper and other five calculation methods are compared and analyzed. In addition, the influence of filling height, filling modulus, culvert size and subgrade modulus on the earth pressure concentration factor at culvert crown is discussed. The results show that under different embankment filling height, the earth pressures calculated by the theoretical formula proposed in this paper, numerical simulation method and pressure concentration coefficient method are similar. The variation of modulus of embankment filling and subgrade has great influence on the proposed theoretical formula results and numerical simulation results. Under the condition of high embankment fill on culvert crown, the calculated results by the proposed method in this paper are closer to the measured values in situ than those of other methods, which can provide reference for the calculation of earth pressure on culvert underlying flexible subgrade.