一、概述铜街子水电站导流明渠右侧混凝土重力式挡墙,是主体坝段基坑施工时的纵向围堰,其中桩号0+40.25～0+70.25段与左岸冲砂底孔坝段组成厂房安装间平台。由于挡墙墙基的细长柱状节理玄武岩(P_2β_5~(1-2)),层内错动带L_c密集,其摩擦系数tgφ=0.35～0.42;粘着力c=0,产状微倾向下游及河床,最不利的视倾角 I. Overview The concrete gravity retaining wall on the right side of the diversion channel of Tongjiezi Hydropower Station is a longitudinal cofferdam for foundation pit construction of the main dam section, in which the station 0 + 40.25-0 + 70.25 and the left bank Composition of plant installation platform. Due to the slender columnar jointed basalt (P_2β_5 ~ (1-2)) with wall-basement, the intra-layer staggered band L_c is dense and the friction coefficient tgφ = 0.35 ~ 0.42; the cohesion c = 0; Riverbed, the most unfavorable apparent dip