砂土中隧道施工条件下管土相互作用的室内模型试验研究

发布时间：2018-09-18 10:55

【摘要】：为分析砂土中隧道施工条件下管线与土体相互作用的机理,利用室内模型试验,自制模型箱,以江砂为填料,选取高密度聚乙烯管材进行试验。结果表明:在砂土中,与穿既有管线轴线相垂直的下穿隧道施工过程中,管线中间部位主要受下拉效应影响,而上拱效应则支配着管线两侧的变形;管线的存在对土层位移的影响范围约为水平向距管线轴线3倍的直径;随着地层损失量的增大,管线与土层的变形曲率比值逐渐减小,管线的弯矩与应变相应增大;隧道施工条件下管线上覆荷载有增大的趋势,管线中间部位管底土压力逐渐趋于零,管线与土层分离区宽度随着地层损失量的增大逐渐增大并趋于一恒定值;通过对管土相互作用机理的探讨,明确了沉降槽宽度系数i、中心最大沉降量smax以及管线埋深与管径比值H/D等因素对管土相对刚度的影响,基于室内模型试验结果提出了管土相对刚度的计算式。
[Abstract]:In order to analyze the mechanism of the interaction between pipeline and soil under tunnel construction in sandy soil, high density polyethylene (HDPE) pipe was selected to test by using indoor model test, self-made model box and river sand as filler. The results show that in the construction process of the tunnel perpendicular to the axis of the existing pipeline, the middle part of the pipeline is mainly affected by the pull-down effect, while the upper arch effect dominates the deformation of both sides of the pipeline. The influence range of pipeline on soil displacement is about 3 times diameter of horizontal distance from pipeline axis, with the increase of formation loss, the ratio of deformation curvature of pipeline to soil gradually decreases, and the bending moment and strain of pipeline increase accordingly. Under the condition of tunnel construction, the overburden load on the pipeline increases, the pressure of the bottom soil in the middle part of the pipeline tends to zero, the width of the separation zone between the pipeline and the soil layer increases with the increase of the amount of formation loss and tends to a constant value. Through the discussion of the interaction mechanism of pipe and soil, the influence of the factors such as the width coefficient of settlement trough i, the maximum settlement of center smax and the ratio of buried depth to diameter of pipeline H / D on the relative stiffness of pipe and soil are determined. Based on the results of indoor model tests, a formula for calculating the relative stiffness of pipe and soil is presented.
【作者单位】：南通城市建设集团有限公司;东南大学岩土工程研究所;南京林业大学土木工程学院;
【基金】：国家自然科学基金项目(51508279)
【分类号】：U451.5

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