模型盾构隧道管片纵缝接头设计方法

Design method for longitudinal segment joints of shield tunnel model

考虑到拼装的缩尺模型管片环与原型管片环的纵缝接头刚度相似性难以满足要求,建议缩尺模型隧道采用开槽模型接头,并分别得到了采用两侧同时开槽、内侧开槽及外侧开槽的模型接头设计计算方法。通过开槽模型接头的管片环模型与梁—弹簧模型的计算结果比较,表明开槽模型接头的设计方法可行,开槽模型接头能很好地模拟拼装管片接头。在综合考虑开槽模型接头的开槽宽度对管片环结构内力与变形的影响与开槽模型接头的加工可行性的基础上,建议开槽模型接头对应的管片环中心角取值为3°~5°。提出的开槽模型接头设计计算理论可用于缩尺模型管片环的纵缝接头设计及在惯用法均质圆环的基础上进行局部抗弯刚度折减的数值模型隧道的建模。

In consideration of the similarity between the bending stiffness of longitudinal joint of an installed scale model segment ring and that of the corresponding prototype one which is difficult to be satisfied, application of grooved model joints for a scale model for shield tunnel is proposed. The design method for the grooved model joints, slotted at both sides, slotted internally and slotted externally, is obtained. By comparing the calculated results of a model segment ring with grooved model joints with those of a beam-spring model, it is verified that the design method for the grooved model joints is feasible, and that the grooved model joints can simulate the installed ones well. After the analysis of influence of slotting on the internal width force and deformation of the segment ring, it is proposed that the corresponding central angle of the grooved model joints should be 3°to 5°. The proposed design theory of the grooved model joints is applicable for the design of a longitudinal joint of the scale model segment ring and for the numerical simulation based on uniform rigidity ring with bending rigidity to be reduced locally.