修正惯用法中弯曲刚度有效率的影响因素分析及计算方法

Analysis and calculation method of effective bending rigidity ratio in modified routine method

修正惯用法作为一种实用的设计计算方法被广泛应用于盾构隧道结构设计领域。其关键参数——弯曲刚度有效率的取值对于计算结果具有至关重要的影响。本文基于荷载结构法,采用有限元方法建立带接头和不带接头的衬砌管片圆环模型。根据弯曲刚度有效率的定义,分析了接头数量、接头角度、接头抗弯刚度和地基抗力系数对于弯曲刚度有效率的影响。研究表明当接头数量较少,接头刚度较大和地基抗力较大时,弯曲刚度有效率较大。同时,不同的接头角度对于弯曲刚度有效率也存在明显影响。根据数值模拟结果,给出了盾构隧道结构的弯曲刚度有效率计算方法。该方法综合考虑接头数量、接头角度、接头抗弯刚度和地基抗力系数对弯曲刚度有效率的影响。一系列计算对比验证了该计算公式具有较广的适用性和较高的准确性。

As a practical calculation method for the lining structure of shield tunnels,the modified routine method has been widely applied during its design.The key parameter,the effective bending rigidity ratio,is essential for the calculated results.The numerical models for segmental rings with and without joints are established using the load structure method.Based on the results of the FEM analysis,the influences of number,distribution and bending stiffness of joints and soil resistance coefficient on the effective bending rigidity ratio are examined.The study indicates that the effective bending rigidity ratio increases when the number of joints decreases or the bending stiffness of joints and the soil resistance coefficient increase.In addition,the distribution of joints has appreciable impact on the effective bending rigidity ratio.A method for evaluating the effective bending rigidity ratio of shield tunnel structures is proposed.The effects of number,distribution and bending stiffness of joints and soil resistance coefficient are considered.Through comparisons,the proposed method is proved to be practical and accurate.