不同构型盾构隧道管片密封垫防水性能分析

Waterproof Performance Analysis of Different Shield Tunnel Segment Gasket Configurations

为研究大直径盾构隧道管片接缝密封垫截面构型对防水性能的影响,分别构建三角形、圆形、半圆+三角形构型密封垫数值模型,分析不同张开量、错台量组合下密封垫接触应力。研究结果表明,三角形及圆形构型封垫接触应力呈两头大、中间小的趋势分布,截面实心区域压缩反力较大,传递到接触面出现峰值应力,开孔区域应力较小。错台压缩中密封垫变形及受力状态更复杂,随着错台量的增加,接触面更扭曲,接触路径发生改变。随着错台量的发展,三角形和圆形构型密封垫接触路径变长,半圆+三角形构型密封垫接触路径缩短。结合箱型图分析,提出以中位数接触应力作为评价指标,该指标能排除异常值,反映的接触面情况更加真实。

In order to study the influence of cross-sectional configuration of gaskets at the joints of large-diameter shield tunnels on waterproof performance,numerical models of gaskets with triangular,circular and semi-circular+triangular configurations were constructed,and the contact stress of gaskets under different combinations of opening and misalignment was analyzed.The results show that the triangular and circular gaskets contact stress is distributed with a large distribution at both ends and a small distribution in the middle.The compression reaction force in the solid area of the cross-section is relatively large,and peak stress appears when transmitted to the contact surface.The stress in the open hole area is relatively small.The deformation and stress state of the gasket in staggered compression are more complex.As the amount of misalignment increases,the contact surface becomes more twisted and the contact path changes.With the development of misalignment,the contact paths of triangular and circular gaskets become longer,while the contact paths of semi-circular and triangular gaskets become shorter.Based on the box plot analysis,a median contact stress evaluation index is proposed,which can eliminate outliers and reflect the contact surface situation more accurately.