水压力作用下岩石统计损伤本构模型研究

为了探究水压力对岩石损伤的影响,在多孔材料弹性理论框架内,利用有效应力原理,结合连续损伤力学和统计理论把霍克-布朗(Hoek-Brown)准则作为微元体强度破坏准则,建立水压力作用下的岩石统计损伤本构模型;并根据残余强度和峰值强度的关系对损伤变量进行修正,使模型能够更好地反映岩石峰后阶段的软化特征。通过室内试验进行模型验证和参数分析,结果表明:建立的模型能够较好地反映水压作用下岩石的应力-应变关系;随着水压力的增大,模型参数n呈增大趋势,岩石的脆性度增高,参数F₀呈减小趋势,岩石的强度降低;峰值点法在确定模型参数时优于曲线拟合法。研究成果对于水压力作用下岩体工程的安全分析有一定的参考价值。     

基于温度实测资料的抽水蓄能电站渗压统计模型及其应用

根据原型监测资料建立多元统计模型,可以及时地分析和监控大坝基础的工作状态。现有模型中的温度分量多用傅里叶函数来表示,无法精细反映坝基不同部位温度的实际分布特征。针对此种不足,以埋设于坝体不同部位的温度计的实测值作为温度分量,建立了渗压统计模型。以一抽水蓄能电站为例,分别建立了传统的基于傅里叶函数表示温度分量的和基于坝体温度计实测值的渗压统计模型,并采用逐步回归方法进行求解。结果表明,采用后一模型更为有效。     

基于CE-QUAL-W2模型的三峡水库神农溪库湾水流水温特性分析

三峡水库蓄水以来,库区干、支流水文水动力变化显著。通过现场观测和构建三峡水库神农溪支流库湾立面二维水动力模型(CE-QUAL- W2),对比研究了三峡水库不同时期水流、水温时空分布特征。研究结果表明:神农溪库湾水体整体流速缓慢,不同时期均存在不同强度的异重流现象,包括干流倒灌异重流和上游入流底部顺坡异重流;枯水运行期和汛前消落期干流水体从表层潜入库湾,强度较弱;汛期和汛末蓄水期存在中层倒灌并且强度较大,影响整个库湾;上游入流处由于来流水温一般低于库湾,存在入流底部顺坡异重流现象。库湾水温呈春夏升温、秋冬降温的变化趋势,一年四季均存在水温分层现象;但冬季分层相对较弱,其它季节水温分层明显;水温分层模式因异重流的存在,明显不同于一般水库的水温分层。对比分析表明,CE-QUAL-W2模型可较为准确地反映神农溪库湾水流及水温时空分布特性。研究可为更细化分析三峡水库神农溪库湾水流水温特性、开展水华预报提供技术支撑。     

A Water Model for Water and Environmental Management at Mae Moh Mine Area in Thailand

It is revealed that the water quality in Mae Moh Reservoir, Thailand, has been deteriorated by lignite mine drainage and power station effluent. This study aims to manipulate water quantity and quality to reduce environmental impacts in Mae Moh area through a model for water management. The model was constructed on the basis of materials balance to predict water flow, which includes concentrations of TDS and SO ^2– ₄. Data collected during 1996–2000 were used. Model validation showed that the mean of predicted and actual values of TDS and SO ^2– ₄ load were significantly similar at 95% confidence limit. The test result is acceptable and the water model can be used as a tool for water system management in the area. In 2006, Mae Moh mine excess water will be discharged at 10.76 Mm³, with a pH of 7.3, TDS and SO ^2– ₄ concentrations of 2,547 and 1,803 mg/l, respectively. Mae Moh power station effluent will be 14.59 Mm³, with pH of 7.1, TDS and SO ^2– ₄ concentrations of 610 and 358 mg/l, respectively. Predicted results showed that the outflow of Mae Moh Reservoir will be 83.67 Mm³ and the concentrations of TDS and SO ^2– ₄ will be as high as 1,501 and 822 mg/l, respectively. Mine excess water management measures are recommended according to the following strategy. All mine excess water should be stored during dry season. During wet season, 50% of the excess water should be stored and the remaining treated at 90% of TDS removal before being discharged. The end result would be a significant improvement in water quality in the Mae Moh Reservoir over the 4-year period to 2010. Pollutants in terms of TDS would be reduced by 35% from 1,501 mg/l in the beginning of 2006 to 975 mg/l at the end of 2009.