海底隧道泥水盾构始发端头加固范围研究

Research on the Reinforcement Range of the Starting End of Submarine Tunnel Slurry Shield

依托于青岛地铁跨海隧道某区间盾构始发案例,通过综合考虑盾构几何尺寸、板块强度理论以及土体滑移理论对理论公式进行了改进,确定了纵向加固长度h=16.1m;根据土体扰动极限平衡理论计算得出相应的径向加固范围:隧道两侧的加固长度为B=3.75m,拱顶为H_(1)=5.64m,拱底为H_(2)=3m,与实际加固范围相差不大;针对工程地质特点,提出了一种综合洞门素墙、“U”型素墙、套管咬合桩以及后退式注浆的盾构始发端头加固方式,可为青岛地区跨海隧道盾构始发提供参考。

Based on the starting case of an interval shield of the cross-ocean tunnel of Qingdao metro,the theoretical formula is improved by comprehensively considering the shield geometry,plate strength theory and slippage theory of soil mass,and the longitudinal reinforcement length h=16.1m is determined;according to the ultimate balance theory of soil mass disturbance,the corresponding radial reinforcement range is calculated:the reinforcement length on both sides of the tunnel is B=3.75m,the arch crown is H_(1)=5.64m,and the arch bottom is H_(2)=3m,which is not different from the actual reinforcement range;based on the characteristics of engineering geology,a kind of reinforcement method for the starting end of shield tunnel is put forward,including comprehensive portal plain wall,U-shaped plain wall,casing interlocking pile,and backward grouting,so as to provide reference for the starting of shield tunnel in cross-ocean tunnel in Qingdao area.