刘家峡水电站大坝坝基承压水异常分析

2003年某水电站坝基承压水水压发生十分罕见的大范围、大幅度异常突降，一夜之间承压水水位下降23.8 m，自动化监测系统记录了突变全过程。文中根据自动化观测数据，分析异常期间大坝变形、扬压力、渗流量的变化以及对大坝安全的影响;并根据形变场与渗流场相互作用，提出坝基承压水水压与基岩岩块变形位移相互作用的机理关系，得到了实测数据的支持和验证。坝基承压水异常后，承压水水位与库水位的相关关系甚好，其相关系数大于0.997，标准差小于0.07 m，回归方程满足真值方程的条件，对形变场与渗流场耦合作用和短时间形变回弹

ANALYSIS OF ABNORMALITY OF THE FOUNDATION CONFINED WATER OF LIUJIAXIA DAM

The pressure of the confined water of a hydropower station experienced an abrupt fall in a significant scale and extent in 2003. The confined water level dropped 23.8 m Overnight. The automatic monitoring system recorded the change of dam deformation, uplift pressure and seepage volume and its influence on the safety of the dam during that anomalous period. Based on the mechanism of interaction between deformation field and seepage field, this paper proposes the mechanism of interaction between the confined water of the dam foundation and the bedrock deformation and sliding, and the mechanism is verified with field data. After the anomalous confined water level fall, the confined water level has a good correlation with the reservoir water level, the correlation coefficient being larger than 0.997 and standard deviation smaller than 0.07 m. The regression equation falls in the range of true value, which is of significance to the study of the coupling mechanism between deformation field and seepage field and the research on springback of deformation within a short period of time.