金安桥电站库区边坡路基变形研究

很多公路位于河岸或库岸地段,由于库(河)水位的变动导致地下水的升降,进而引起路基的沉降或隆起,会产生不均匀变形,从而引起路面结构破坏,甚至产生滑坡。本文以金安桥电站库区路基边坡为研究对象,建立库区边坡二维饱和-非饱和渗流模型,模拟水库不同工况下边坡渗流场演变规律并进行库岸路基的非饱和沉降计算,分析库水位变化对路基沉降或隆起的影响。分析表明,库岸路基边坡变形与库水位升降及其速率有关。当库水位上升时,此库岸路基和边坡发生了隆起变形;当库水位下降时,此库岸路基和边坡发生了沉降变形。且近库岸边坡和路基的沉降或隆起受库水位升降影响较大,远离库岸的边坡和路基的沉降或隆起受库水位升降影响较小,库岸路基沉降与库水位下降速率快慢成正相关关系。

Roadbed deformation on reservoir bank for Jin'anqiao hydropower station

At the present time, many roads are built along a riverbank or reservoir bank. But changes in groundwater table as responses to the changes in reservoir stage, could cause the roadbed to subside or uplift, even into uneven deformation, resulting in failure of pavement structures and even landslides. In this work taking the study case of Jin'anqiao reservoir, a two-dimensional saturated-unsaturated seepage model for slopes in the reservoir region has been developed to simulate the time evolution of seepage flow in the conditions of water stage fluctuations, and to analyze the corresponding unsaturated subsidence of reservoir bank roadbeds, along with the influence of changes in reservoir stage on roadbed subsidence or uplift. The results show that the roadbed deformation is related to the fluctuations in reservoir stage and its time rate of change. First, the reservoir bank roadbeds and slopes take uplift deformation as reservoir stage rises, while they take subsidence deformation as the stage falls. Second, the subsidence or uplift of the slopes and roadbeds closer to reservoir bank depend more on the fluctuations in reservoir stage than do those farther away from the bank. Finally, there exists a positive correlation between the subsidence of reservoir bank roadbeds and the falling rate of reservoir stage.