The Mechanism of Ground Collapse Induced by Leakage of Underground Pipelines in Saturated Sandy Soil Areas of River Alluvial Plains
River alluvial plain is the main area for urban construction in China,and is dominated by loose alluvial sediments in lithology.The damage of underground pipe networks often resulted in the loss of loose strata to form highly concealed underground cavities,which in turn induced ground collapse and threatened the safety of people and property as well as city infrastructures.Taking the ground collapse of Changfeng Road in Anqing City as an example,this work established a controllable proportional solid model box with multiple fields of seepage and stress,and conducted urban ground collapse simulation experiments.The development process of cavities after the damage of water pipelines and the stress changes in various directions around the cavities were analyzed in order to reveal the formation mechanism of ground collapse.Results indicate that:(1)Urban ground collapse progressed through three stages,from small holes,to vertical holes,and finally collapse pits,with underground abnormal holes serving as precursors for early warning.(2)The environment prone to urban ground collapse in river alluvial plain was characterized by the presence of high-permeability layers in the stratigraphy and the groundwater level.A pipeline leak,particularly a sewage pipeline leak,is the triggering factor.(3)The severity of urban ground collapse was primarily controlled by the relative depth of pipelines compared to groundwater level.The size of collapse pits can be calculated and evaluated based on stratigraphic properties.This research provides a theoretical basis for the risk assessment,prevention,and control zoning of urban ground subsidence.
urban ground collapsesaturated sanddisaster mechanismalluvial plainChangfeng RoadAnqing City
万方数据
维普
