Impact of water delivery pipeline leakage on collapsible loess foundations and treatment methods

The Yumenkou Eastward-Expansion Water Pumping Project is an important pipeline for water network construction in Shanxi Province, China. This pipeline is vital for the development of cities and agricultural lands along its path. However, the foundation of the water delivery pipeline is mostly located in collapsible loess strata, thereby affecting project safety. To investigate the feasibility of foundation treatment schemes for the water delivery pipeline, a numerical analysis model is proposed in this study based on the analyzes of the leakage of water pipelines and different foundation treatment schemes through laboratory tests, field tests, and numerical simulations. Results show that the deeper the loess layer is, the smaller the collapsible deformation is and the greater the initial collapse pressure is. Furthermore, the deeper the buried pipeline is, the greater the collapsible deformation is after water leakage. A 0.5 m-thick lime-stabilized soil cushion layer is the most economically reasonable solution among the simulated scenarios. The collapsible deformation caused by pipeline leakage can be divided into three stages: start-up, development, and stabilization. Addressing the leakage point during the start-up stage is crucial. The proposed numerical analysis model can provide an important basis for similar engineering designs.