复杂明挖并行隧道群施工沉降控制技术研究

Research on Settlement Control Technology for Construction of Complex Open-cut Parallel Tunnel Groups

针对超大型复杂明挖并行隧道群工程不均匀沉降问题,文章依托成都天府国际机场下穿飞机滑行道段隧道群工程,通过数值模拟与理论分析相结合的方法,对下穿飞机滑行道的复杂城市明挖隧道不均匀沉降控制进行了研究,分析了其沉降控制标准和沉降控制措施,并通过有限元模拟施工全过程。结果表明:(1)在下穿机场的明挖隧道群回填区域采用改良土或混凝土等材料来代替普通回填土,可有效控制地表沉降;(2)采用桩基设计承担回填土重量以控制填土的不均匀沉降和总体沉降,有利于保证隧道群及机场运营期间的正常使用。

In view of the uneven settlement issue of super-large complex open-cut parallel tunnel group projects,this paper is based on the tunnel group project of an aircraft taxi way section passing under Chengdu Tianfu International Airport,and studies the control of uneven settlements of the complex urban open-cut tunnel under the under-pass aircraft taxiway through the approach of combining numerical simulation and theoretical analysis,analyzes the settlement control criteria and measures,and simulates the whole construction process through finite element simulation.The results show that:(1)the use of materials such as improved soil or concrete to replace ordinary backfill soil in the backfill area of the open-cut tunnel group passing under the airport can effectively control the ground settlement;(2)pile foundation is used to bear the weight of the backfill soil to solve the problem of the uneven and overall settlement of the backfill soil,which is conducive to ensuring the normal use of the tunnel group and the airport during operation.