城市地铁隧道交叉段稳定性分析

发布时间：2018-04-29 12:03

本文选题：地铁隧道 + 安全距离　；参考：《西安理工大学》2017年硕士论文

【摘要】：本文主要研究城市地铁隧道交叉段的稳定性问题,选取正在快速发展的西安地区地铁线路,根据已建成的地铁线路的勘测数据,在已有建成的上行线路的基础上,根据理论选用下行线路截面,然后运用ABAQUS软件,分别计算出不同的交叉角度(30°、45°、60°、90°),不同的地层岩性(黄土地层、古土壤地层、粉质粘土地层)所对应的安全距离,通过控制变量法,对各个参数进行对比分析,研究安全距离随交叉角度变化的规律以及三种地层之间的安全距离的关系,最后又对比分析了不同强度衬砌混凝土对结构位移的影响。主要内容如下:1、根据《地铁设计规范(GB 50157-2003)》中要求的地铁隧道施工后变形必须小于20mm的要求作为控制标准,分不同交叉角度、不同地层岩性逐个试算并确定各个交叉工况下的安全距离,其中在90°正交情况下,黄土地层的安全距离为0.9D,古土壤地层的安全距离为1D,粉质粘土地层的安全距离为1.05D,三者有所差别,但都在1D附近,与已有的研究结果相吻合,证明了结果的正确性;2、在其他条件不变的情况下,改变交叉角度计算安全距离。对比分析得到:交叉角度的减小引起结构的位移增大,使得安全距离增大,但安全距离随着交叉角度的减小而增大的速率是逐渐减小的,并非线性的,这在三种地层中的表现是一致的,因此在地铁交叉时安全距离的设计中不能简单地进行线性插值;3、对不同地层在相同情况下的安全距离进行了对比分析,得到:黄土地层的安全距离最小,粉质粘土地层的安全距离最大,古土壤次之,而在不同的交叉角度中,三者之间的关系却不成规律,因此三者之间的大小关系可以确定,但数值关系却不能相互估算;4、本文的最后章节就衬砌结构的混凝土强度对结构的位移的影响程度的进行了仿真计算分析,可以得到,隧道衬砌结构的混凝土强度的提高,会引起结构的位移减小,而计算数据表明强度提高所引起的位移减小的程度微弱,因此通过提高衬砌结构混凝土强度的办法来减小结构位移效果不太明显,并且并不经济。
[Abstract]:This paper mainly studies the stability of the cross section of the urban subway tunnel, selects the subway line in Xi'an area which is developing rapidly, and according to the survey data of the completed subway line, on the basis of the established uplink line, According to the theory, the downlink cross section is selected, and the safe distance corresponding to different cross angles (30 掳~ 45 掳~ 60 掳~ 90 掳) and different strata lithology (loess layer, paleosol stratum, silty clay formation) is calculated by controlling variable method, using ABAQUS software. The relationship between the safety distance and the cross angle is studied. Finally, the influence of lining concrete with different strength on the displacement of the structure is compared and analyzed. The main contents are as follows: 1. According to the requirements in the Subway Design Code (GB50157-2003), the subway tunnel deformation after construction must be less than the requirement of 20mm as the control standard, with different cross angles. The lithology of different strata is calculated one by one and the safe distance under different cross working conditions is determined, in which 90 掳orthogonal case, The safe distance of loess layer is 0.9D, that of paleosol formation is 1D, and that of silty clay formation is 1.05D. It is proved that the result is correct and the safety distance is calculated by changing the cross angle under the condition that other conditions are not changed. The comparative analysis shows that the decrease of the cross angle increases the displacement of the structure and makes the safe distance increase, but the rate of the safe distance increases gradually with the decrease of the cross angle, and it is nonlinear. This performance is consistent in the three strata, so we can not simply carry out linear interpolation in the design of the safety distance when the subway is crossing. The safety distance of different strata under the same conditions is compared and analyzed. It is concluded that the safe distance of loess layer is the least, the safety distance of silty clay formation is the largest, paleosol is the second, and the relationship between the three is irregular in different cross angles, so the size relationship between the three can be determined. However, the numerical relation can not be estimated mutually. In the last chapter of this paper, the influence degree of concrete strength of lining structure on displacement of structure is simulated and analyzed. It can be concluded that the concrete strength of tunnel lining structure is improved. The calculated data show that the displacement caused by the strength increase is weak, so it is not obvious and economical to reduce the displacement by increasing the strength of the lining structure concrete.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U452.1

【参考文献】