白鹤滩水电站尾水出口围堰拆除爆破设计与施工  

Design and Construction of Demolition Blasting for Cofferdam at Tailrace Outlet of Baihetan Hydropower Station

作　　者：吴发名 段兴平 徐进鹏 杨招伟 周涛 彭正良 WU Fa-ming;DUAN Xing-ping;XU Jin-peng;YANG Zhao-wei;ZHOU Tao;PENG Zheng-liang(China Three Gorges Construction Engineering Corporation,Chengdu 610000,China;Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China;Powerchina Sinohydro Engineering Bureau 14 Co.,Ltd.,Kunming 650041,China)

机构地区：[1]中国三峡建工(集团)有限公司,成都610000 [2]长江水利委员会长江科学院水利部岩土力学与工程重点实验室,武汉430010 [3]中国水利水电第十四工程局有限公司,昆明650041

出　　处：《爆破》2023年第1期100-107,共8页Blasting

基　　金：国家自然科学基金青年基金项目(52109148)。

摘　　要：白鹤滩水电站尾水出口围堰拆除爆破具有工期紧、任务重、岩石条件复杂、近距离靠近保护物、水流冲渣要求高等突出特点。针对施工中的重难点,采取“分期分区分层”爆破拆除方案,将单个围堰分为“两期三层八区”,通过预留经济围堰,提前拆除水上部分等措施,克服了工程量大、工期紧的难题;采用“大直径钻机造孔、孔内套管护孔”的方式,有效减少了复杂地质条件下塌孔的产生,提高了施工工效也确保了爆破效果;“高单耗、低单响”的药量设计、“孔间分段、孔内延时”的爆破网路设计,即能满足近距离爆破条件下质点振速安全控制要求,又确保了爆后渣料块度满足水流冲渣条件。工程应用结果表明,最不利工况下爆破诱发质点峰值振速为11.85 cm/s,小于结构混凝土允许的安全控制标准12 cm/s;实测水击波峰值压力为0.12 MPa,小于水工钢闸门的安全允许控制值0.4 MPa;爆后绝大部分渣料块度粒径控制在40 cm以内,大块率控制在5%以内,爆破效果良好,满足水流冲渣条件。The demolition blasting of the tailrace outlet cofferdam of Baihetan hydropower station has obvious characteristics of tight construction schedule,heavy task,complex rock conditions,close proximity to protective objects and high requirements for slag washing by water flow.In view of the important and difficult points in the construction,a phased,partitioned and layered blasting demolition scheme was adopted,and thus the single cofferdam was divided into two phases,three layers and eight zones.By reserving an economic cofferdam and demolishing the part above water in advance,the difficulties of huge engineering quantity and tight construction schedule were overcome.The method of drilling with large-diameter drills and protecting the hole with casing effectively reduced the occurrence of hole collapse under complex geological conditions,improved the construction efficiency and ensured the blasting effect.The design of high powder factor,low single shot,inter-hole segmentation and intra-hole delay not only met the requirements of safety control of vibration velocity,but also ensured that the rock fragmentation after blasting can be washed away by water flow.The engineering application results showed that the peak vibration velocity of blasting under the most unfavorable conditions was 11.85 cm/s,which was less than the allowable safety control standard of 12 cm/s for structural concrete.The measured peak pressure of surge wave was 0.12 MPa,which was also under the allowable value of 0.4 MPa for hydraulic steel gates.The fragmentation after blasting was controlled mostly within 40 cm,and the boulder yield was controlled within 5%.The research results can provide reference for similar projects.

关 键 词：围堰拆除 爆破设计 爆破施工 尾水出口 白鹤滩水电站 

分 类 号：TD235.3[矿业工程—矿井建设]