句容抽蓄上水库筑坝料E-B模型分期反演参数对比分析

Comparison of Parameters of E-B Model for Upper Reservoir Backfill Materials Determined by Stage Back-analysis in Jurong Pumped Storage Station

为预测句容抽蓄上水库坝体和库盆在竣工期和蓄水后产生的变形,利用施工期上库主坝和库盆的变形监测资料,对填筑料E-B模型参数进行分期反演。在此基础上,采用第三期反演参数,对竣工期和蓄水后的库盆变形特性进行预测和分析。研究表明,利用早期短时序坝体变形监测资料得到的模型反演参数偏大,随着坝体填筑高度的增加,采用后期长时序变形监测资料反演得到的模型参数逐渐减小并趋于真实值;在E-B模型中引入初始应力状态参数S0可以考虑现场压实坝料的超固结特性,S0越大,坝体变形越小,经历高强度碾压后的填筑料S0在0.40~0.55之间;基于第三期反演参数的库盆竣工期沉降计算结果与实测结果总体吻合较好。研究结果可用于指导工程实践。

To predict the deformation of the dam body and reservoir basin of the Jurong Pumped Storage Power station during the completion period and after impoundment,the stage back-analysis were conducted to determine the parameters of E-B model of the backfill materials in the upper reservoir by using the deformation data monitored during the construction period.Base on the back-analysis parameters in the third stage,the deformation characteristics of the dam and basin of upper reservoir after completion and impoundment were predicted.The results show that the back-analysis parameters obtained by using the deformation monitoring data in the early short-time period are comparatively large,while the parameters back analysis by using the deformation monitoring data with long-time duration decrease gradually to the true values.Introducing the initial stress state parameter S0 into the E-B model can reflect the over-consolidation characteristics of the in-situ compacted dam material,the larger the value of S0,the smaller dam deformation predicted.The value of S0 for backfill materials of dam after high strength compaction is between 0.40 and 0.55.For the settlement for the upper reservoir after completion,the predicted value by using the parameters obtained through the third stage back-analysis agrees well with the monitoring value.The result of this study can be used to provide reference in the engineering.