在传统刚度有效率研究的基础上, 采用弹性力学的变刚度梁计算方法进行了隧道位移和变形的计算, 由此得到了简化的纵向刚度有效率计算表达式. 实例分析表明: 随着螺栓个数的增加和半径的增大, 隧道纵向刚度有效率和纵向等效刚度均增大; 但是随着螺栓个数的增加, 纵向刚度有效率表现为同方向、近线性关系; 同时随着螺栓半径的增大, 纵向刚度有效率表现为同方向、近抛物线关系; 而随着管片厚度和管片混凝土模量的增大, 纵向刚度有效率降低. 在此基础上考虑由管片刚度改变引起的应力集中, 研究了埋深对刚度有效率的影响, 结果表明, 随着埋深的增加刚度有效率呈线性降低, 即隧道纵向等效抗弯刚度减小. 研究结果对盾构隧道设计具有一定的指导意义.
Based on the studies of conventional longitudinal equivalent rigidity ratio, the tunnel’s displacement and deformation are calculated using a variable rigidity beam elasticity calculation method. A simplified expression of the tunnel’s longitudinal equivalent rigidity ratio is obtained. The analysis shows that the longitudinal equivalent rigidity ratio is linearly proportional to the number of bolts. At the same time, the longitudinal equivalent rigidity ratio nearly parabolically increases with the increasing of the bolt radius. However, with the increase of segment ring thickness and the segment modulus of elasticity, the longitudinal equivalent rigidity ratio is reducing. Because of the stress concentration caused by the tunnel’s rigidity change, the tunnel longitudinal equivalent bending rigidity and effectiveness of the rigidity reduce with the increasing of depth. The proposed model is more widely applicable and is of reference value for longitudinal stability design of shield tunnels.
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