不均匀沉降作用下连续单舱综合管廊横截面内力分析

Analysis of cross-sectional forces of continuous single-cabin utility tunnel under uneven settlement

纵向不均匀沉降不仅会改变长线型综合管廊横截面受力状态,也是导致综合管廊结构破坏无法正常运营的重要原因之一。针对矩形截面连续单舱综合管廊,建立了考虑因纵向不均匀沉降引起的综合管廊相邻横截面之间剪切传递效应和挤压效应的横截面内力理论分析模型,基于该模型推导不均匀沉降作用下连续综合管廊横截面内力分布公式,与三维单舱管廊-土体相互作用数值模拟结果进行对比并验证其合理性。研究发现:建立的理论分析模型与数值模型相比,在横截面关键点处结构内力峰值相差不超过20%,可以较为精确地对综合管廊在不均匀沉降作用下的内力进行评估;假定综合管廊沿纵向的不均匀沉降符合高斯曲线分布,沿结构纵向会受到不均匀的附加弯矩和附加剪力,进而引起管廊横截面内力发生较为显著变化。提出的不均匀沉降作用下连续综合管廊横截面关键点内力值计算公式可为综合管廊的结构设计提供参考。

Longitudinal uneven settlement leads to changes of the cross-sectional forces of a long utility tunnel,which is also a crucial reason causing the utility tunnel structural damage and cannot operate normally.For the rectangular cross-section continuous single-compartment utility tunnel,an analytical model of cross-sectional internal force and deformation that considers the shear and compression effects between adjacent sections caused by the longitudinal uneven settlement was established,and the model was used to derive the cross-sectional forces along the utility tunnel.Moreover,the analytical results were subsequently compared with the three-dimensional soil-utility tunnel interaction model for validation.It is found that the analytical model established in this paper can accurately calculate the internal force of the utility tunnel under the effect of uneven settlement,and the differences in peak internal force of the structure at key points of the cross-section are less than 20%.It is assumed that the longitudinal uneven settlement of the utility tunnel follows a Gaussian distribution.This uneven settlement results in uneven additional bending moment and shear force along the longitudinal direction of the structure,consequently leading noticeable changes of the cross-sectional forces of the utility tunnel.The proposed analytical solutions of the internal forces in the cross section of the continuous utility tunnel under the uneven settlement proposed in this study can provide reference for the structural design of the utility tunnel.