Vertical Earth Pressure Simulation Test Analysis of the Buried Pipeline

In order to analyze the vertical earth pressure of trench buried pipeline, a large pipeline project in Gansu Province is taken as the research background. A three-dimensional discrete element model of buried pipeline is established by using PFC3D numerical analysis method, and the pipe-soil interaction process in the process of soil post-construction settlement is simulated. The distribution law of pipe top earth pressure and vertical soil pressure under different buried depth and pipe diameter were analyzed and compared with field test and theoretical calculation. The results show that the displacement of soil particles increases continuously in the process of settlement, and finally tends to be stable, and the contact force between the pipe top and the soil reaches the maximum; the distribution law of the earth pressure on the pipe top obtained by field test and numerical simulation is approximately "big in the middle". The parabola distribution of "small on both sides", and the vertical earth pressure on the top of the pipe increases with the increase of the buried depth of the pipeline. The influence of pipe diameter on the vertical earth pressure of pipe top is small, and the overall trend decreases with the increase of pipe diameter; the numerical simulation is closer to the calculation theory of earth pressure, and the Marston calculation theory is more conservative. The research results can provide theoretical reference for ditch buried pipelines in similar sites.