闹市地铁石质基坑的非爆开挖施工技术

Non-blasting Excavation Technique for Rocky Base Pits of Metro Project at Downtown Area

厦门市轨道交通1号线镇海路站是地下两层(局部地下三层)侧式车站,位于厦门市老城区,周边旅游景点密集、交通量大、环境复杂、且紧邻建筑物;车站基坑石质开挖方量大,岩层单轴抗压强度达到180 MPa以上,开挖难度大.传统的爆破开挖会造成周边建筑震速超标、爆破警戒影响交通、基坑界面不易控制、噪声和粉尘污染严重等问题.本文对石质基坑非爆破开挖方法进行了比选,最终确定采用圆盘锯切割+静态破碎修整基坑壁的施工方案,并对其施工流程、相关参数、施工工艺、施工措施等进行了阐述.实践表明:以圆盘锯切割+静态破碎的施工技术,质量可控,安全可靠,确保工期,有利于城市环境保护,达到了良好的社会经济效益,这对指导闹市地铁石质基坑的开挖施工有十分重要的意义.

Being one underground two-storey<partially three storey)side-type station,Zhenhai Road Station on Metro Line 1 of Xiamen City is located at old city district of Xiamen,where tour spots are dense,trafie is heavy,surrounding environment is complicated,and buildings are in the vicinity.The base pit of the station has a large quantity of stone excavation work,uniaxial compressive strength of the stone stratum hits 180 MPa plus,and therefore the pit excavation is quite a challenge.Traditional blasting technique may lead to oversized vibration speed of the surounding buildings,the influence that blasting warning has on traffic,pit faces that cannot be easily controlled,as well as some issues like noises and dust pollution etc.Through comparisons of non-blasting excavation techniques for rocky base pits,the author finally adopts the construction technique where disc saw cuting and static breaking&trimming pit walls are put together,and also elaborates associated construction flows,parameters,techniques and measures,etc.The practice shows that the technique of disc saw cutting together with static breaking is controllable in terms of quality,safe and reliable,and can ensure construction period,benefits municipal environment protection,and has achieved good social and economic results.This is of great meaningfulness to guiding rocky pit excavation of metro projects at downtown areas.