填土对既有浅埋隧道的安全影响及容许填土厚度确定

发布时间：2018-05-11 08:06

本文选题：既有隧道 + 浅埋隧道　；参考：《铁道学报》2014年09期

【摘要】：既有浅埋隧道上方填土可能导致其衬砌变形、安全系数降低,甚至发生破坏,危及行车安全。以长枪岭隧道上方某拟建公园填土工程为例,选取若干典型断面,对既有浅埋隧道受不同厚度的填土影响进行数值分析,并确定容许填土厚度。结果表明:既有隧道上方填土将导致衬砌整体下沉,左右两侧沉降基本对称,位移值自上而下逐渐减小;填土后的安全系数降低,但幅度不大,拱脚及仰拱处安全系数偏小,可能出现开裂;既有隧道拱顶位移值随着填土厚度的增加而近似线性增大,为满足位移控制要求,容许填土厚度应为0.3 H~0.4 H(H为原覆土厚度)。根据若干断面的分析结果可得整个填土区域的容许填土线,在此范围内进行填土施工,并采取相应的工程措施,既有隧道的运营安全可得到保证。本分析方法简单易行,满足工程精度,可用于指导工程实践,对类似工程有一定的借鉴意义。
[Abstract]:The overfill of shallow buried tunnel may lead to lining deformation, safety factor decrease, even damage, endangering traffic safety. Taking a proposed park reclamation project above Changqanling tunnel as an example, some typical sections are selected to analyze the influence of different thickness of fill on the existing shallow buried tunnel, and to determine the allowable fill thickness. The results show that the overfill of the existing tunnel will result in the overall subsidence of the lining, the settlement of the left and right sides will be basically symmetrical, the displacement value will gradually decrease from the top to the bottom, the safety factor after filling will be reduced, but the range is small, and the safety factor of the arch foot and the inverted arch will be small. Cracks may occur, and the displacement of the arch roof of the existing tunnel increases approximately linearly with the increase of the fill thickness. In order to meet the requirements of displacement control, the allowable thickness of the fill should be 0.3 H ~ (0.4) H ~ (-1) H ~ (-1) as the thickness of the original overlying soil. According to the analysis results of some sections, the allowable fill line of the whole fill area can be obtained, and the construction of the fill is carried out within this range, and the corresponding engineering measures are taken. The safety of the existing tunnel can be guaranteed. This analysis method is simple and practical, satisfies the engineering precision, can be used to guide the engineering practice, and has certain reference significance to the similar engineering.
【作者单位】：中铁第五勘察设计院集团有限公司;
【分类号】：U452.1

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