温寨航电枢纽工程围堰爆破拆除技术实践

Practice of Cofferdam Demolition by Blasting in Wenzhai Navigation-power Junction Project

基于温寨航电枢纽工程纵向混凝土围堰爆破拆除案例,对工程进度、爆破区域周边环境及爆破方案进行研究,采用变线密度装药与工业电子雷管起爆网路相结合的方案,对围堰成功实施爆破拆除。拆除体横断面呈上窄下宽结构,钻扇形垂直超深孔,孔内采用变线性密度装药,且利用减弱松动爆破爆破作用指数(n=0.4~0.6)和炸药单耗(0.5~0.75 kg/m^(3))来控制各线密度长度和各段线装药密度,并根据周围建(构)筑物和生态环境的保护要求导出最大单响药量来实施拆除爆破。经爆破监测:爆破有害效应均控制在安全允许之中。拆除体质量符合设计要求。

Based on the blasting demolition case of longitudinal concrete cofferdam of Wenzhai hydro-junction project,the project schedule,surrounding environment of blasting area and blasting scheme were studied in this paper,the cofferdam was successfully demolished by blasting with a combination of variable linear density charge and the initiation network of industrial electronic detonator.The cross section of the demolition body is narrow in the upper part and wide in the lower part.The fan-shaped arrangement vertical ultra-deep hole is drilled,and the variable linear density charge is adopted in the hole.In addition,the linear density length and linear charge density of each section are controlled by decreasing the loose blasting action index(n=0.4~0.6)and the powder factor(0.5~0.75 kg/m^(3)).According to the protection requirements of the surrounding buildings and ecological environment,the maximum single blasting charge quantity is derived for demolition blasting.Through blasting monitoring,the harmful effects of blasting are controlled in safety.The quality of demolition body meets the design requirements.