富水粉细砂地层小半径曲线盾构始发安全进洞技术

SAFE ENTRY TECHNOLOGY OF SMALL RADIUS CURVE SHIELD IN WATER RICH SILTY FINE SAND STRATUM

始发端盾构机进洞是盾构法施工的重点,其施工质量直接关系后续施工的安全与效率。本文针对太原地铁2-1号线联络线隧道由于曲线半径小及穿越稳定性极差的富水粉细砂地层导致盾构进洞安全问题突出的特点,提出了确定盾构合理始发方向的方法,通过端头井地层加固及洞门变径密封装置等技术措施,保证了盾构安全始发。通过数值模拟方法分析了盾构始发过程中引起地表沉降特征,并与现场监测结果进行对比,证明了盾构进洞方案的有效性,为今后类似工程提供指导和借鉴经验。

The entry of shield machine at the starting end is the focus of shield construction,and its construction quality is directly related to the safety and efficiency of subsequent construction.In view of the prominent safety problems of the shield entering the tunnel of the connecting line of Taiyuan Metro Line 2-1 due to the small curve radius and crossing the water rich silty fine sand stratum with extremely poor stability,this paper puts forward the method to determine the reasonable starting direction of the shield,and ensures the safe starting of the shield through technical measures such as end well stratum reinforcement and tunnel door diameter changing sealing device.Through the numerical simulation method,the characteristics of surface settlement caused by the shield starting process are analyzed and compared with the field monitoring results,which proves the effectiveness of the shield entering tunnel scheme,and provides guidance and reference experience for similar projects in the future.