兰州地铁下穿黄河段同步注浆参数控制研究

Study on the Control of Synchronous Grouting Parameters of the Tunnel Section beneath the Yellow River of Lanzhou Subway

以兰州轨道交通1号线泥水盾构下穿砂卵石黄河地层为工程背景,对同步注浆施工过程中的浆液类型、注浆压力、注入率、注浆量以及注浆速率参数进行研究.通过统计与有限元方法分析,得到如下结论:对比三种同步注浆浆液的类型的优缺点,得到同步注浆的浆液为单液硬性浆,然后用有限元软件Plaxis对下穿黄河段注浆压力进行数值分析,计算了隧道中心线埋深分别为15m、21m、27m情况下,注浆压力为0.2MPa、0.4MPa、0.6MPa、0.8MPa、1.0MPa下盾构隧道中心线位移,确定盾构隧道穿越黄河段的注浆压力为0.4MPa;分析现场盾构施工实际参数,得到注浆率控制在130%~180%,注浆量为4.3~6m3,注浆速率为0.07~0.17m3/min.

Based on the engineering background of slurry shield of Lanzhou Rail Transit Line 1 tunneling through sandy and pebble Yellow River stratum,the grouting type,grouting pressure,grouting rate,grouting volume and grouting rate parameters in the process of synchronous grouting construction are studied.Through statistical analysis and finite element analysis,the following conclusions are drawn:by comparing the advantages and disadvantages of the three types of synchronous grouting slurry,it is concluded that the synchronous grouting slurry is a single-fluid hard slurry.Then the grouting pressure of the down-traversing section of the Yellow River is numerically analyzed by using the finite element software Plaxis.When the depth of the tunnel center line is 15 m,21 m and 27 m,the grouting pressure is 0.2 MPa,0.4 MPa,0.6 MPa,0.8 MPa,1.0 MPa under each depth,the center line displacement of the shield tunnel is calculated.The grouting pressure of the tunnel crossing the Yellow River section is 0.4 MPa.Based on the analysis of the actual parameters of shield tunnel construction,the grouting rate is controlled at 130%~180%,the grouting volume is 4.3~6 m3,and the grouting rate is 0.07~0.17 m3/min.