护盾式TBM隧道回填层对管片受力的影响

发布时间：2018-03-15 00:38

本文选题：盾构隧道　切入点：弹性抗力系数　出处：《中国公路学报》2017年08期 　论文类型：期刊论文

【摘要】：为了探明回填层对护盾式TBM隧道运营阶段管片受力的影响,建立考虑回填层的围岩抗力系数计算方法,为隧道设计中地层抗力系数的确定提供理论基础,设计相应的模型试验,对比了有回填层和无回填层时管片的受力特点,并采用厚壁圆筒理论推导了围岩-回填层等效弹性抗力系数的计算方法。研究结果表明:有回填层和无回填层时,管片运营阶段的弯矩、轴力、变形具有较大的差别,回填层的作用不可忽略;回填层厚度、泊松比、弹性模量、管片外半径均对围岩-回填层等效弹性抗力系数产生影响,其中回填层弹性模量为主要影响因素;回填层存在一个临界弹性模量,当回填层弹性模量大于临界弹性模量时,计算得出的围岩-回填层等效弹性抗力系数大于围岩弹性抗力系数,回填层对围岩起到增强作用,研究给出了回填层临界弹性模量计算公式,并得出回填层临界弹性模量取值与围岩弹性模量密切相关;考虑回填层的数值计算结果更接近模型试验结果,验证了围岩-回填层等效弹性抗力系数计算方法的准确性。
[Abstract]:In order to find out the influence of backfill layer on segment force of shield TBM tunnel in operation stage, the calculation method of wall rock resistance coefficient considering backfill is established, which provides a theoretical basis for determining stratum resistance coefficient in tunnel design, and designs corresponding model tests. The stress characteristics of segments with and without backfill are compared, and the calculation method of equivalent elastic resistance coefficient of surrounding rock and backfill is deduced by using thick wall cylinder theory. The results show that when there is backfill and without backfill, the equivalent elastic resistance coefficient of surrounding rock and backfill is calculated. The bending moment, axial force and deformation of segment in operation stage have great difference, the function of backfill layer can not be ignored, the thickness of backfill layer, Poisson's ratio, elastic modulus and outer radius of segment all have influence on the equivalent elastic resistance coefficient of surrounding rock and backfill layer. Among them, the elastic modulus of backfill is the main factor, and there is a critical modulus of elasticity in backfill, when the elastic modulus of backfill is larger than that of critical elastic modulus, The equivalent elastic resistance coefficient of the surrounding rock and backfill is greater than that of the surrounding rock, and the backfill plays an enhanced role on the surrounding rock. The formula for calculating the critical elastic modulus of the backfill is given. It is concluded that the critical elastic modulus of backfill is closely related to the elastic modulus of surrounding rock, and the numerical calculation result considering backfill is closer to the model test result, which verifies the accuracy of the calculation method of equivalent elastic resistance coefficient between surrounding rock and backfill.
【作者单位】：西南交通大学土木工程学院;西南交通大学交通隧道工程教育部重点实验室;
【基金】：国家自然科学基金项目(51208434) 重庆市应用开发计划重点项目(cstc2014yykfB30003)
【分类号】：U455.4

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