大奔流沟料场高边坡支护设计研究与实践

Research and practices of support design of high slope in Dabenliugou quarry

锦屏一级水电站大奔流沟料场岩质边坡设计最大高度达458 m,综合坡比1∶0.56。根据现场实际地质条件,确定边坡开挖支护设计的主要原则是:沿层面开挖剥离,开挖不切脚;采用喷锚支护对表层岩体结构面的不利组合和岩体局部变形进行支护;采用锚索重点对坡顶、坡腰和坡脚进行深层加固;对岩体完整性不好的坡面采用框格梁连接锚头混凝土进行支护;采用排水孔和坡面排水系统相结合的方式进行排水。边坡于2009年3月开挖施工,至2013年6月底,已开挖形成的边坡最大高度约413.5 m,监测成果表明,边坡整体稳定。

The maximum design height of rock slope of Dabenliugou quarry for Jinping I Hydropower Station is 458 m and the average slope ratio is 1：0.56.According to the actual geological conditions,the main principles of the slope excavation and support design were determined as follows： excavating and stripping along the rock stratum and maintaining slope foot undisturbed;supporting unfavorable structural plane composition and local deformation zone of rock mass on the surface by spray achoring;reinforing top,waist and foot of the slope by anchor cable;reinforcing slope surface of poor integrity by concrete frame beams with anchor heads;water drainage by combined methods of drainage holes and slope drainage system.The maximum height of slope excavation was up to 413.5m at the end of June 2009.Monitoring results show that the slope is in a stable state in general.