百色水利枢纽地下厂房工程主变洞的开挖方法

百色水利枢纽水电站工程为地下厂房工程，主变洞与主厂房平行布置且相互间隔20m。该工程主变洞的上下游侧在不面高程分别布置有垂直岩锚吊车梁基础，开挖要求质量很高；主变洞的施工进度受合同条款节点辫标的控制，工期紧；在进行主变洞第Ⅲ层开挖施工过程中，主厂房岩壁吊车梁的混凝土浇筑施工同时进行，施工干扰大。针对这些情况，负责承建的施工单位开展QC小组活动，对主变涸的开挖采用控制爆破方法，通过合理的开挖程序使主变洞的开挖取得良好的效果。

The Excavation Methods of Main-transformed Cavern of Underground Powerhouse of Baise Water Conservation Junction

Baise Water Conservation Junction is an underground powerhouse with parallel main-transformed cavern and major powerhouse in a distance of 20 meters. The upper and lower reach of the main-transformed caverns are arranged respectively with vertical rock-anchored crane beams and are of high quality. The construction process is progressing strictly in accordance with contract goals, in a short timeframe. The third layer excavation of the main-transformed cavern is con- strueted in the same time with concreting of rock crane beam of the powerhouse, which brings obstruction to each other. To this end, the contracting company carrys on the quality control activities and adopts blasting control and the rational excavation procedures to achieve admirable results.