软弱围岩特大断面洞室爆破开挖优化设计——以巴基斯坦莫赫曼德水电站为例  

Optimization design of cavern blasting excavation with large cross-section in soft surrounding rock:an example of Mohmand Hydropower Station in Pakistan

作　　者：陈永建 唐存建 朱建成 CHEN Yongjian;TANG Cunjian;ZHU Jiancheng(China Gezhouba Group International Engineering Co.,Ltd.,Beijing 100025,China;China Gezhouba Group No.3 Engineering Co.,Ltd.,Xi'an 710077,China)

机构地区：[1]中国葛洲坝集团国际工程有限公司,北京100025 [2]中国葛洲坝集团第三工程有限公司,陕西西安710077

出　　处：《水利水电快报》2022年第7期66-71,共6页Express Water Resources & Hydropower Information

摘　　要：对于特大断面软岩洞室,通常采用分部分层的开挖方法,这会对施工安全、质量以及进度等方面存在一定影响。以巴基斯坦莫赫曼德(Mohmand)水电站项目导流隧洞工程为例,在原洞室Ⅳ类围岩上层分部开挖方案的基础上,优化了爆破设计,结合爆破振动监测数据,进行最大单响药量控制,将洞室上层分部开挖方案调整为上层全断面开挖。现场爆破试验结果表明:优化后的爆破施工方案残孔率达90%以上,洞室平均线超挖仅为12.10 cm,减少了喷射混凝土用量。优化后的爆破设计保证了施工过程的质量和安全,降低了施工成本,加快了施工进度。Under the condition of soft surrounding rock,the cavern with large cross-section is usually excavated by sections and layers,which constraints on construction safety,quality and progress.In this paper,the diversion tunnel project of Mohmand Hydropower Station in Pakistan is taken as an example.On the basis of the excavation scheme of upper section of classⅣsurrounding rocks of the original cavern,the blasting design is optimized,and combined the monitoring data of blasting vibration,the maximum single blast charge is controlled and the section excavation scheme of the upper cavern is adjusted to full cross-section excavation for the upper cavern.The field blasting test results showed that:the residual rate of the optimized blasting construction scheme is more than 90%,and the average over-excavation of the tunnel is only 12.10 cm,thus reducing the amount of shotcrete.The optimized blasting design can not only ensure the quality and safety of the construction process,but also reduce the construction cost and speed up the construction progress.

关 键 词：软弱围岩 特大断面 洞室开挖 光面爆破 振动监测 莫赫曼德水电站 巴基斯坦 

分 类 号：U455[建筑科学—桥梁与隧道工程]