小间距下穿高铁隧道控制爆破技术

因2015年雨季兰渝高铁龙凤隧道内地下水涌出,致其停运,故在线下增建泄水洞,要求必须在2016年雨季前贯通。该泄水洞距上方运营高铁仅5 m,为保证高铁的运营安全,对爆破振速控制要求极为严格。介绍了此工程中所采用的爆破方法、爆破参数和起爆方式,并最终引入了电子雷管错相减振技术以及相应的起爆时差。由于施工区域地质复杂,围岩等级较高,岩石硬度大。通过试爆段的多次爆破监测数据显示,爆破振速以及主频都远远大于一般类似工程。传统非电毫秒延时方式已彻底无法满足工程要求,普通电子雷管逐孔起爆方法亦无法使得振速得到有效控制,所以最终采取了数码电子雷管错相减振技术。施工过程表明,电子雷管错相减振方式的工程爆破效果良好,减振效果明显,保证了泄水洞如期贯通,避免了高铁再次因雨停运。可为类似的工程作为参考。

Controlled blasting technology of underpass the high speed railway tunnel with small interval

Because of the drainage problem,the high-speed rail line of Lanzhou to Chongqing was out of service during 2015 wet season,so a drainage tunnel was constructed for the line and required to be accomplished before 2016 wet season.This drainage tunnel was only 5 meters below the line,the blasting vibration need to be strictly controlled.All the applied blasting method,parameters and detonation throughout the entire project were introduced,finally brings in the electronic detonator stagger phase technique and corresponding time difference for detonation.The construction site had complicated geology with hard rock.The trial blasting results showed that the peak particle velocity and basic frequency of blasting wave were far larger than the results in similar projects.Conventional method was ineffectual for reducing blasting vibration,and the hole by hole method with electronic detonator could not always have apparent effect,consequently,the stagger phase method with electronic detonator was adopted.Construction results exhibit the prominent blasting effect by using stagger phase method,blasting vibration was effectively controlled.Drainage tunneling was ensured completed before wet season,high-speed rail was prevented from being out of service.It could provide a reference to similar engineering project.