盾构空推过矿山法隧道关键技术研究

Key Technology of Pushing an Empty Shield Through a Mining Excavated Tunnel

结合深圳地铁10号雪象站~甘坑站区间隧道施工项目,对盾构空推过矿山法隧道的关键技术进行了研究。实践表明:(1)采用50 cm厚C25混凝土G20@150双排玻璃纤维筋临时封闭掌子面,然后施作C15素砼回填,防止了盾构与矿山法隧道接口处管片错台;(2)盾构空推过矿山法隧道时,盾构机推进速度宜在15~40 mm/min;(3)通过喷射豆石对管片进行支撑,增加了盾构前移摩擦力,防止了管片下沉和错台;(4)为防止空推时管片上浮或下沉,待管片拼装完成后,在管片吊装孔处安装支顶;(5)针对初支断面欠挖导致盾构机空推困难这一难题,采用三维激光扫描检测技术,快速确定欠挖部分,节约了空推过隧作业时间。

Combined with the tunnel construction project between Xuexiang Station and Gankeng Station of Shenzhen Metro Line 10,the key technologies of pushing an empty shield through a mining excavated tunnel are studied.The construction practice shows that:(1)using 50 cm thick C25 concrete to temporarily seal the tunnel face with G20@150 double rows of glass fiber reinforcement,and then backfill with C15 plain concrete to prevent segment dislocation at the interface between shield and mine tunnel;(2)when the shield passes through the mining excavated tunnel,the advancing speed of the shield machine should be 15~40 mm/min;(3)the segment is supported by shotcrete,which increases the forward friction of the shield and prevents the segment from sinking and staggering;(4)in order to prevent the segment from floating or sinking,the supporting roof should be installed at the segment lifting hole after the segment assembly is completed;(5)aiming at the problem that the under-excavation of the initial support section leads to the difficulty of pushing an empty shield,the under-excavation part is quickly determined by using the three-dimensional laser scanning detection technology,which saves the working time of pushing an empty shield through the tunnel.