白鹤滩特高拱坝坝肩柱状节理玄武岩开挖爆破试验研究  

Experimental Study on Blasting of Columnar Jointed Basalt of Baihetan High Arch Dam

作　　者：阿旺加措 冯佳佳 刘美山[5] 郭增光[4] 刘天斌 索朗欧珠 NGAWANG Gyatso;FENG Jia-jia;LIU Mei-shan;GUO Zeng-guang;LIU Tian-bin;SUOLANG Ou-zhu(College of Science,Tibet University,Lhasa 850000,China;College of Engineering,Tibet University,Lhasa 850000,China;Three Gorges Group Tibet Energy Investment Co.,Ltd.,Lhasa 850000,China;China Three Gorges Projects Development Co.,Ltd.,Chengdu 610041,China;Changjiang River Scientific Research Institute,Wuhan 430015,China;Tibet Geological Survey,Lhasa 850000,China)

机构地区：[1]西藏大学理学院,拉萨850000 [2]西藏大学工学院,拉萨850000 [3]三峡集团西藏能源投资有限公司,拉萨850000 [4]中国三峡建设管理有限公司,成都610041 [5]长江科学院,武汉430015 [6]西藏地质调查所,拉萨850000

出　　处：《爆破》2022年第2期63-74,共12页Blasting

基　　金：中国长江三峡集团有限公司科研项目资助(JG/18037Y);基于蒙特卡洛法考虑温度效应的台阶式边坡稳定性评价(XZ2019ZRG-16(Z));西藏大学研究生高水平人才培养计划项目(2020-GSP-B012)。

摘　　要：柱状节理玄武岩具有表面易破碎、易松弛等性状特点,作为300 m级高拱坝坝肩基岩世界罕见。柱状节理玄武岩基岩面岩体施工处理,经常出现边坡预裂面破坏,预裂面超欠挖严重、预裂面半孔率低、岩体扰动等问题。为解决破碎岩体边坡开挖的稳定,减少预裂爆破对建基面稳定的危害,根据白鹤滩水电站左岸坝肩柱状节理玄武岩物理及力学特性,通过预裂爆破与光面爆破对比试验,以确定爆破类型;并优化预裂爆破装药线密度、孔排距等参数。结果表明:预裂爆破综合效果优于光面爆破。通过在爆前、爆后布置物探监测仪器对周围岩体损伤进行监测,得出预裂爆破孔0.6 m的间距及线密度240 g/m装药参数,对柱状节理玄武岩实现基岩面扰动最小,达到最佳爆破效果。为强卸荷岩体高拱坝基础开挖提供了理论和实践借鉴。As the characteristics of fragile surface and easy relaxation,it is rare that the columnar jointed basalt is the base rock of the 300 m high arch dam abutment.During the construction of bedrock surface on the columnar jointed basalt rock,some problems often occur,such as destruction of the pre-crack surface of slope,serious pre-excavation of the pre-crack surface,low half-hole ratio of pre-crack surface and rock mass disturbance.In order to solve the stability problem of the broken rock mass excavation and reduce the pre-splitting blast damage to the foundation surface stability,a blasting type was determined by comparison test of the pre-splitting blasting and smooth blasting according to the physical and mechanical characteristics of the columnar jointed basalt on the left bank of Baihetan Hydropower Station.Meanwhile,The parameters of charge line density and hole row spacing of pre-split blasting were optimized.The results show that the comprehensive effect of pre-splitting blasting is better than smooth blasting.The damage of surrounding rock mass was monitored by arranging geophysical monitoring instruments before and after explosion.The blasting parameters of 0.6 m spacing of pre-splitting blasting hole and 240 g/m linear density are obtained,which can minimize the disturbance to the bedrock surface of columnar jointed basalt and achieve the best blasting effect.It provides theoretical and practical reference for foundation excavation of high arch dam with strongly unloaded rock mass.

关 键 词：柱状节理玄武岩 爆破试验 参数优化 物探监测 

分 类 号：TD235.3[矿业工程—矿井建设]