盾构隧道通用管片结构力学行为与控制拼装方式研究

Study on Mechanical Behavior and Controlling Assembling Modes of Universal Segment Lining for Shield Tunnel

采用梁-弹簧模型模拟管片结构、荷载-结构模型计算作用在管片结构上的荷载,并借助有限元法对不同拼装方式下地铁区间盾构隧道通用管片结构进行力学行为分析。结果表明:通用管片结构在不同拼装方式下的力学行为是不相同的,与拼装类型、分析目标环的环向和纵向接头的位置、封顶块的位置有关;错缝拼装控制通用管片结构正负弯矩、剪力、纵向螺栓剪力设计值;通缝拼装控制变形量和地层抗力设计值。对于内力较大的拼装方式,在施工中应采用回避的方式解决,所以配筋设计中可只按一般的内力值进行计算,以便减少管片结构的配筋量和减小螺栓直径,从而降低工程造价。

Simulating segment lining with the beam-spring model and calculating loads acting on segment lining with the load-structure model, the mechanical behavior of universal segment lining under different assembling modes for the metro section of the shield tunnel is analyzed with the finite element method. The results show that. The mechanical behavior of universal segment lining is different under different assembling modes, which relates to the assembling types, places of transverse and longitudinal joints and position of the seal roof block of the objective segment ring; design values of positive and negative moments, shearing force of segment liming and shearing forces of longitudinal bolts of universal segment lining are controlled with staggered joint assembling, and design values of deformation and surrounding rock resistances are controlled with straight joint assembling. The assembling modes with biggish internal forces should be avoided in construction. In order to reduce the quantity of reinforcing bars and bolt diameters, reinforcement is calculated and designed according to the general internal forces. Consequently the project cost may be decreased.