软土地区基坑开挖对下卧隧道的影响分析

发布时间：2018-09-19 16:37

【摘要】：隧道上方基坑开挖会引起下卧隧道的收敛变形,对某城市地下通道基坑开挖引起的下卧隧道收敛变形进行了系统的分析研究。结果表明,基坑开挖使下卧隧道产生横向压缩变形,隧道收敛变形的影响范围约为沿隧道轴线方向基坑长度的5倍。隧道收敛在基坑开挖区间较大并且向两侧减小。下卧隧道管片的横向压缩变形与管片的泊松比μ和土体的有效内摩擦角φ'有关。软土地区,隧道收敛变形的最大值一般出现在基坑边缘附近,基坑中心具有较小的收敛变形。基坑漏水使隧道上方土体产生附加应力,隧道发生横向拉伸变形。隧道收敛随基坑开挖时间的增加而增大,底板完成后隧道顶部由于上部竖向附加应力增加和底板的约束作用,隧道收敛变形具有一定的反弹。得到的结论可为相似工程提供参考和借鉴。
[Abstract]:The convergent deformation of the underground tunnel caused by the excavation of the foundation pit above the tunnel will cause the convergence deformation of the tunnel. The convergence deformation of the tunnel caused by the excavation of the foundation pit of a city underground passage is systematically analyzed and studied. The results show that the excavation of foundation pit causes transverse compression deformation of the tunnel, and the influence range of tunnel convergence deformation is about 5 times of the length of foundation pit along the axis of tunnel. The tunnel converges in the excavation interval and decreases to both sides. The transverse compression deformation is related to the Poisson's ratio 渭 of the segment and the effective angle of internal friction of soil. In soft soil, the maximum convergent deformation of tunnel occurs near the edge of foundation pit, and the center of foundation pit has smaller convergent deformation. The leakage of foundation pit causes the additional stress of the soil above the tunnel and the transverse tensile deformation of the tunnel. The tunnel convergence increases with the increase of excavation time. After the bottom plate is completed, the tunnel top has a certain rebound due to the increase of the vertical additional stress in the upper part and the restraint of the bottom plate. The conclusion can provide reference for similar engineering.
【作者单位】：浙江科技学院土木系;
【分类号】：TU753;U456.3

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