地面出入式盾构隧道修正惯用法计算参数研究

盾构隧道衬砌内力计算常用方法为修正惯用法,其计算参数一般根据经验选取。基于壳-弹簧模型,考虑接头抗弯刚度与接头轴力弯矩的非线性关系,对地面出入式超浅埋盾构隧道修正惯用法的关键计算参数抗弯刚度效率系数η和弯矩调整系数ξ的取值进行分析研究。得到结论:超浅埋盾构隧道η应在规范范围内取最小值,ξ应取最大值,负覆土情况下可偏保守取1。

Study on Ground Penetrating Shield-bored Tunnel Calculation Parameters in Modified Routine Method

Modified routine method is widely used in the calculation of the internal force of shield-bored tunnels, and the calculation parameters are generally selected according to the experience. In the paper, the key calculation parameters of ground penetrating shield-bored tunnel in the modified routine method, i. e. , the stiffness reduction ratio （η） and the moment release ratio （ξ）, are analyzed on basis of shell-spring model, considering the non-linear relationship between the bending stiffness and axial bending moment of the segment joints. Conclusions drawn are as follows ： 1 ） For shield- bored tunnel with super-shallow overburden, the minimum value in the specified range of specifications should be adopted for stiffness reduction ratio （η） and the maximum value should be adopted for the moment release ratio （ξ） ;2） When the top of the tunnel is above the ground surface, value 1 should be adopted conservatively.