岩体卸荷及其产生的变形现象已成为水电工程建设中一个突出的问题。在分析西南水电工程中峨眉山玄武岩岩体卸荷划分方法的基础上,采用已被大多数工程所运用的岩体的张开裂踪条数、裂隙张开度和纵波速度作为卸荷带划分量化指标,对自鹤滩水电站卸荷带进行了划分,证明了此量化指标作为卸荷带划分的统一标准的可行性。进一步结合卸荷带的地质特征,探讨了蛾眉山玄武岩岩体卸荷带划分的统一标准问题,提出了卸荷带划分的建议方案。
The rock mass unloading and its transmutative phenomena has been an extrusive problem in the construction of a hydroelectric power station. At present, there is not a unitive standard to divide the unloading zone. On the basis of analyzing the method for classifying the unloading zones of Emeishan basalts in the project site of a hydroelectric power station in southwestern China, the authors adopt three indexes, that is, opening joint quantity, joint opening degree and wave velocity that have been exercised by many projects as quantitative indexes for classifying the unloading zones. And, they divide the unloading zones of the Baihetan hydroelectric power station using the above three indexes for proving the feasibility of taking the three quantitative indexes as unitive classification standard. Farther, the authors discuss the unitive standard and bring forward the proposition of classifying the unloading zones of Emeishan basalts.