盾构隧道管片衬砌结构纵向刚度问题初步研究

Study on the Longitudinal Rigidity of Segment Lining of Shield Tunnel

研究目的:盾构隧道在穿越地质条件或者地表建筑物差异大的路段时,管片衬砌结构在纵向将产生较大的内力和变形,故在盾构隧道管片衬砌结构设计中,必须考虑其纵向力学问题。研究结论:(1)盾构隧道纵向等效刚度系数计算公式为:ηX=kxl/(kxl+(M1G1/ls)(1-1/n))(X表示拉、剪切和弯曲)。(2)通过进行简化有限元计算,得出单线地铁区间盾构隧道纵向抗弯等效刚度系数近似取为:ηM=0.05。

Research purposes： When a shield tunnel traverses the section with different geological conditions or surface buildings, longitudinal deformation and internal forces for segment lining will be produced. So, longitudinal mechanical problems of the shield tunnel must be considered in design of the segment lining. Research conclusions： （ 1 ） The theoretical formula of equivalent rigidity coefficients for tension, shearing and bending is ηX=kxl/（kxl＋M1G1/ls（1-1/n）, X referring to tension, shearing and bending. （2） The equivalent rigidity coefficient of the segment lining of the shield tunnel in a single subway on the longitudinal bending is O. 05 obtained with FEM （ finite element method）.