超大城市营运地铁车站下方地墙控制爆破  

Controlled Blasting of Ground Diaphragm Wall Under Metro Station in Super Large City

作　　者：刘文广 LIU Wen-guang(Shanghai Fire Technology Engineering Co.,Ltd.,Shanghai 200081,China)

机构地区：[1]上海消防技术工程有限公司,上海200081

出　　处：《爆破》2022年第1期115-119,167,共6页Blasting

摘　　要：既有营运地铁站因其高安全性对爆破振动要求极高,现有规范通常规定在50 m范围外才可实施爆破。工程要求在营运地铁站下方仅2.8 m处,对盾构机穿越区域的车站混凝土连续墙结构进行精确爆破分解,在地铁停运的5 h间隙里完成所有爆破作业,同时要保证地铁站内运营、电气和信号等多种设备的正常使用。通过在地面采用全站仪和水平仪双向控制,把28 m垂直深孔偏斜度控制在5‰;采用30 ms精准毫秒延时爆破形成顶部预裂破碎带、采用分层装药毫秒延时爆破技术,在50 m^(2)穿越区均匀布置72个爆破点等手段;爆破后盾构穿越的结果表明破碎粒径在15 cm以下,与爆破对象同一结构的车站站台,距离爆点5.6 m处实测爆破振动峰值3.4 cm/s,达到了既保证营运车站安全又保证盾构机穿越效果的双重目的,爆破后地铁站结构和电气设施安全运行。The sub-way station in operation is extremely sensitive to blasting vibration.Existing regulations usually stipulate that blasting can only be carried out outside 50 m.The project requires accurate blasting decomposition of the concrete diaphragm wall in the area where the shield machine crosses only 2.8 m below the operating subway station.All blasting work should be completed within 5 hours when the subway stops running.Meanwhile,the normal use of operation,electrical and signal equipment and other equipment in the subway station should be ensured.The deviation of 28 m vertical deep hole is controlled within 5 through the bidirectional control of total station and level on the ground.Precise millisecond time delay blasting with 30 ms is used to form a presplitting fracture zone at the top.Layered charging millisecond time delay blasting is adopted and 72 blasting points are evenly arranged in the 50 m^(2) crossing area.The results of shield machine excavation after blasting show that the crushing particle size is less than 15 cm,and the station platform with the same structure as the blasting object is 3.4 cm/s on blasting vibration velocity at the station platform 5.6 m away from the explosion point,which achieves the dual purpose of ensuring the safety of the operating station and the crossing effect of the shield machine,and the subway station structure and electrical facilities operate safely after blasting.

关 键 词：控制爆破 地铁车站 地下连续墙 泥水盾构机 

分 类 号：TD235.3[矿业工程—矿井建设]