大朝山水电站地下厂房枢纽布置和地下洞室群围岩支护设计

大朝山水电站受所处坝址地形、地质、水文条件等因素限制，电站厂房只能采用地下厂房方案．厂房、主变室、尾调室三大洞室轴线方位和洞室相对位置受厂房区断层的影响被限在目前位置．地下洞室群的设计通过对围岩稳定进行有限元分析、地质力学模型试验、局部不稳定块体分析，分别按各部位地质条件进行了支护设计．

Layout of Underground Powerhouse Complex and Support Design of Surrounding Rocks around the Group of Underground Chambers atDackaoshan Bydropower Station

Constrained by the topographic,gedlogical and hydrological conditions around the damsite, the undreground powerhouse scheme can only be adopted as the powerhouse in Dachaoshan Project. Axial directions of the powerhouse, main transformer chamber and tailrace surge chamber,their relative positions are constrained at the present locations by the effect of enormous fault which exists nearby. Finite-element analysis,geomechanics model test and stability analysis of non-stationary local rocks were carried out for the surrounding rocks around the group of underground chambers. Support design was made according to their geological conditions separately.