针对向家坝水电站地下厂房岩壁梁地质条件异常复杂、岩台宽度窄、承受荷载大、质量要求高和工期紧迫等特点和难点，贯彻“精细爆破”理念，通过采取合理的开挖顺序、自行设计钢管钻孔样架以确保钻孔精度、双层光面爆破和均匀微量化装药、错孔布置及预锚锁角等技术和工艺措施，对炸药爆炸能量释放与岩体破碎等进行精密控制，以确保岩壁梁的开挖成型质量，取得了优良的爆破效果：岩台光爆孔半孔率分别为Ⅱ类围岩100 %，Ⅲ类围岩99.2 %，Ⅳ类围岩90 %～97.3 %；岩壁无欠挖，平均超挖仅2.9 cm；不平整度为0～4 cm；因爆破和围岩卸荷造成的影响深度在0.2～0.7 m。

The geology condition of Xiang jiaba hydraulic power station underground workshop is very complicated. Characteristics of crane beam of rock wall construction embodied in width of rock bench, huge bearing load, high quality requirements, urgent construction period and so on. According to inherent conception of “precision blasting”, technological measures of optimized excavation sequence, steel tube frame for drilling, double smooth blasting, equal and minim explosive and plum blossom shaped holes were adopted in construction. Through which, precision control of explosive energy release and rock fragmentation were achieved, insured the blasting excavation quality. Half-hole rate in Ⅱ surrounding rock was 100%, in Ⅲ surrounding rock was 99.2%, in Ⅳsurrounding rock was 90~97.3%, the phenomenon of under break was avoided absolutely, the average over break value was only 2.9cm, the non-smoothness is 0~4cm, the influence depth because of blasting excavation unloading was 0.2~0.7cm, the excavation effect was nearly perfect.