某水利枢纽工程泄洪排砂洞进口边坡稳定性监测分析

Monitoring and Analysis of Inlet Slope Stability for the Flood and Sediment Releasing Tunnel of a Multi-Purpose Dam

边坡的失稳破坏,都有一个从渐变到突变的发展过程,在破坏前会显示出一些即将破坏的征兆。通过安装精密的仪器对坡体的变形进行监测,则可能捕捉到破坏前坡体稳定性的异常信息,可以及时发现问题和采取措施进行处理。坡体的位移是观测的最主要、最直观的物理量;用应力观测检验坡体的支护效果,与变形监测对照分析还可验证监测成果的可靠性。某水利枢纽工程通过埋设3支多点位移计和2支锚索测力计,对裂隙发育、坡面破碎的泄洪排砂洞边坡施工过程中的变形进行了监测分析,监测成果表明泄洪排砂洞进口边坡目前是稳定的。

Losing-stability and failure of slope is a developing process, and some symptoms will appear before its breakage. These symptoms sometimes are very hard to be found just by human＇s intuition and observing, if exact instruments are installed to inspect the slope, we may catch some abnormal information about slope stability when breakage symptoms appear. Analysing these information in time can help us find problem and solve problem as quickly as possible, so losses of people and equipments will be avoided. Displacement of slope is the most important and intuitive observation quantity,stress observation can be used to check shoring effect and validate whether monitoring results are reliable or not by being compared with displacement observation. This project lay three multiple position borehole extensometers and two anchor dynamometers as monitoring instruments on the flood and sediment releasing tunnel inlet slope where crevices are abundant and surface was cracked. The purpose of doing this is to monitor and analyse its displacement during construction process. Monitoring results show that flood discharge hollow inlet slope is still in stable condition.