摘要
根据现场声波检测试验,张河湾上水库砂岩1∶1.75缓倾角边坡开挖,若采用常规的预裂爆破方法形成竖直的预裂面,只有预留较厚的保护层才能有效保护围岩,这将大大增加手风钻的造孔工作量,难以保证开挖工期.为此,采用大直径倾斜炮孔进行预裂爆破以形成与设计边坡平行的预裂面,仅预留3m厚的保护层即成功地保护了围岩,因而大大地减少了保护层的厚度和手风钻的造孔工作量,显著地加快了施工进度,解决了爆破质量要求与施工进度要求之间的矛盾,既保证了施工工期,又明显地降低了钻爆成本.
According to the sound wave examination insitu, it must form a wide reserved protected layer to protect the rock if blast with the traditional presplit blasting method for the sandstone in Zhanghewan Upper Reservoir, for its designed side slope of 1∶1.75. So it will increase the blasting quantity of the protector, that need blasting with small holes and a little explosive, and the work time limit of the project guaranteed with difficulty. Latter blasted with large diameter and incline drill holes to form a presplitting crack that parallels with the designed slope face, it reserved only a protector of 3m thickness and avoided the rock demolition. Thus they have reduced the blasting quantity of the protected layer obviously,and have resolved the contradictory between the demand of construction quality and the rate of progress successfully,not only have guaranteed the time limit of the engineering,but also have reduced the blasting costs.
出处
《三峡大学学报（自然科学版）》
CAS
2005年第3期205-208,共4页
Journal of China Three Gorges University：Natural Sciences
