Earth Pressures of the Buried HDPE Pipe Subjected to Ground Subsidence

The High density polyethylene (HDPE) pipe is widely used in the municipal drainage system due to its merits of light weight, low cost and chemical resistance. The fractures of the buried HDPE pipe caused by the ground subsidence are common occurrence in engineering practice. Many methods for calculation of the earth pressure at the top of the pipe during the construction phase are available, while the method for estimating the earth pressure of the pipe subjected to the ground subsidence is limited. In this study, full-scale model tests are established to explore the distribution of earth pressure around the HDPE pipe subjected to the ground subsidence. HDPE pipes with two inside diameters of 200 and 400 mm are used in the model tests. Movable bottom plates of the model box are designed to generate the ground subsidence. The earth pressure cells are installed at three different profiles along the longitudinal direction of the pipes. The results demonstrate that the soil arching is triggered along both the longitudinal and cross-sectional directions of the pipe subjected to the ground subsidence. The earth pressure at the top of the pipe experiences an overall increase with lowering down the bottom of the model box.