雅砻江官地水电站料场边坡开挖扰动及其影响因素

EXCAVATION DISTURBANCE AND ITS INFLUENTIAL FACTORS ON MATERIAL-YARD SLOPE OF GUANDI HYDROPOWER STATION IN YALONG RIVER

对雅砻江官地水电站竹子坝料场开挖高边坡稳定性及其影响因素进行深入研究;在对边坡失稳破坏模式及岩体力学参数进行分析的基础上,对典型代表性的坡段开挖过程进行非线性有限元模拟,得到边坡应力、位移及其塑性应变等开挖扰动特征及其断层、结构面参数、锚固措施等的影响效应,并对边坡施工过程中及长期稳定性的加固方案提出建议。研究结果表明,采用分步开挖、逐级加固的施工方案对确保边坡的稳定性是有效的,锚固支护不仅可以有效地约束变形,而且还能控制一定方向上的开挖卸荷强度,从而有效降低边坡岩体因开挖卸荷引起的强度损伤或破裂失稳。根据上述研究成果,提出在实际工程应用中进行开挖施工与加固优化的建议;作为重大水电工程的案例研究,所得结论也可对铁路、公路建设中的开挖边坡和矿山的露天矿边坡的治理工程提供一定的参考。

Excavation disturbance is an important factor for engineering slopes stability, and it runs through the whole process of slope excavation. The excavation disturbance and influential factors are researched combined with the material-yard slope of left bank of Guandi hydropower station in Yalong River. Based on the analyses of slope instability mode and mechanical parameters of the rock mass, the nonlinear finite element analysis for typical slope segment including excavation process is carried out, and the excavation disturbance characters and the influential effects of slope are also obtained. The excavation disturbance includes the stress, displacement, equivalent plastic strain, etc., and the influential effects are the parameters of the joint crack and the rocks fault, anchoring method, etc.. And then, the suggestions for reinforcement scheme of slope stability during construction period and long-term operation are proposed. The results show that the construction schemes of excavation by steps and reinforcement by steps are effective for slope stability. Anchorage supports can not only restrain deformation effectively, but also can control strength loss. Bases on the achievements, some suggestions of excavation and reinforcement scheme are presented for practical engineering. As an important case of hydropower project, the results can also be used in the treatment of excavation slope in railway construction, highway construction and open-pit slope.