水电能源科学

针对基于常规小概率法拟定大坝变形监控指标(属于固定限值)存在不收敛、易出现误报警问题，提出了基于分离时效分量的小概率法拟定变形监控指标的计算方法，首先建立大坝变形统计模型分离出时效分量；进而针对扣除时效分量的时间系列变形，分别对比了选取年度极值作为子样本、选取年度最不利库水位和温度对应变形作为子样本以及选取基于正交试验法组合的不利水位和温度对应变形作为子样本，然后进行统计检验，并采用小概率法拟定扣除时效分量的变形容许值，最后叠加时效分量获得大坝不收敛变形监控指标。结合西南某变形不收敛重力坝实测资料分析表明，相对于常规小概率法拟定的监控指标，基于分离时效分量的方法充分考虑到了时间效应，且增强了监控指标的可靠性。

There are problems of non-convergence and easy false alarm when formulating dam deformation monitoring indicators(which belong to fixed limits) based on the conventional low-probability method. A calculation method for formulating deformation monitoring indicators based on the low-probability method of separating aging components is proposed. Firstly, the statistical model of dam deformation is established to separate the time-dependent component. Then, aiming at the time series deformation of deducting the aging component, the annual extreme value is selected as the subsample. The corresponding deformation of the annual most unfavorable reservoir water level and temperature is selected as the subsample. The corresponding deformation of the unfavorable water level and temperature based on the combination of orthogonal test method is selected as the subsample. Then the statistical test is carried out, and the small probability method is used to formulate the deformation allowable value of deducting the aging component. Finally, the aging component is superimposed to obtain the non-convergence deformation monitoring index of the dam. Combined with the measured data of a deformation non-convergence gravity dam in southwest China, the analysis shows that compared with the monitoring index proposed by the conventional small probability method, the method based on the separation time component fully considers the time effect and enhances the reliability of the monitoring index.