大朝山水电站尾水出口围堰爆破拆除测试研究

为确保大朝山水电站按期蓄水发电，1、2号尾水出口围堰拆除工期紧迫，决定采用爆破方式将围堰一次拆除。为确定采用堰内不充水爆破还是堰内充水爆破两种不同方案，结合现场施工进行了水中爆破冲击波的专项试验。试验探索在四周受约束的水工隧洞中爆破水击波的传播特性，并选择适宜的工程防护措施，以确保检修闸门及尾水隧洞的安全，同时为确定爆破方案提供科学依据。围堰拆除爆破水压力及地震效应监测结果表明，尾水检修闸门处的动水压力和震动值以及闸门井、隧洞等重要部位的震动值均在安全范围内。

Test and study on the blasting removal of the cofferdam in the tailrace mouth of Dachaoshan Hydropower Station

In order to ensure the power generation and impoundment of the Dachaoshan Hydropower Station in schedule, it is urgent to remove the cofferdam in the No 1 and No 2 tailrace mouths so that the blasting removal was adopted In order to determine the blasting alternative that is with or without water in the cofferdam, a special test on the underwater blasting shock wave was made The test explored the spread characteristics of blasting shock wave in the hydraulic tunnel and determined the proper engineering protection measures, to ensure the safety of bulkhead gate and tailrace tunnel Meanwhile the test also provided the scientific basis for the determination of blasting alternative The monitoring results on the blasting water pressure and earthquake effect during the cofferdam removal showed that the dynamic water pressure and shock value in the tailrace bulkhead gate and the shock value in some important positions such as gate chamber and tunnel are all within the allowance of safety