沥青混凝土心墙坝应力变形及水力劈裂研究

采用三维非线性有限元法对新疆某沥青混凝土心墙堆石坝进行了应力变形分析,计算中采用邓肯E-B模型作为坝体及心墙的本构模型,对大坝施工和蓄水过程进行了模拟,并采用线弹性断裂力学方法对沥青混凝土心墙是否会发生水力劈裂破坏进行了判定分析。计算结果表明,坝体和心墙应力变形均处在合理范围之内,但心墙中存在一定的拱效应,需要研究其发生水力劈裂的风险。基于线弹性断裂力学理论建立了沥青混凝土心墙水力劈裂判定准则,并在可能开裂处预设裂纹进行水力劈裂判定,结果表明,该裂纹尚不能扩展,沥青混凝土心墙不会发生水力劈裂破坏。

Study on stress-deformation and hydraulic fracturing of rockfill dam with asphalt concrete core

In order to study the static characteristics of rockfill dam with asphalt concrete core in XinjiangProvince, the nonlinear three-dimensional finite element method was employed. The Duncan-Chang E-B model was chosen in this paper to simulate the filling and storing processes of the dam. Based on the theory of linear-elastic fracture mechanics, the hydraulic fracturing analysis of asphalt concrete core is performed. According to the analysis results, the stress intensities and deformation values were within safety ranges, but the asphalt concrete core wall has obvious arching effect. So we need to study the risk of hydraulic fracturing on core. The hydraulically fracturing criterion of the core is established on the based of the fracture mechanics theory, and the probability of hydraulic fracturing on core can be obtained by pre-defined fracture in the possible position. The analysis shows that the fracture could not propagate, local hydraulic fracturing couldn't occur.