某高拱坝坝基辉绿岩脉改造特征及其工程影响

Rebuilding Characteristics of Diabase-dike in a High Dam Foundation and Its Influence on Engineering

通过对我国西南某高拱坝坝基花岗岩体内穿插的辉绿岩脉的侵位和后期构造—热液作用以及浅表改造作用的研究,并对比各组不同走向辉绿岩脉的变形破坏特征,查明坝基辉绿岩脉在其活动后期热液蚀变的基础上,在同一构造应力作用下,各组辉绿岩脉具有不同的主要变形破坏方式,即脉壁张裂、剪切滑移和挤压破碎等,从而控制坝基岩体内与岩脉有关的各种软弱结构面、工程岩体结构及其力学性质,并简要讨论了各组岩脉对拱坝坝基抗滑稳定性和变形稳定性的影响。

Based on the study of the intrusion, tectonic-hydrothermal action and epigene-action of the diabase-dikes in the foundation of a high arch dam in the south west of China and the comparison of their own processes of deformation and failure, it is shown that, after hydrothermal alteration, these processes involve tensile crack of dike wall,＇shear slip and compressive fragmentation under the same environment of tectonic stresses, and thus control the action of planes of weakness, rock mass structure and its mechanical properties associated with the diabase-dike. A brief discussion is given on the effect of diabase-dikes on the stability and deformation of the arch dam foundation.