下穿有砟铁路盾构隧道施工引起轨道沉降分析与控制研究

发布时间：2018-07-07 18:10

本文选题：地铁盾构隧道 + 有砟铁路　；参考：《福建工程学院》2017年硕士论文

【摘要】：随着城市地铁隧道和高速铁路建设规模的不断扩大,地铁隧道下穿既有铁路线路的工程也日益普遍。新建隧道的施工必然会引起既有铁路路基和轨道产生沉降变形,影响列车的安全运行。因此,研究地铁隧道下穿既有铁路引起的沉降变形规律和隧道-路基-轨道三者之间的相互作用机理,科学的制定隧道建设过程中相应的轨道沉降控制办法就显得十分必要。首先,第一阶段对地表沉降进行预测,为了得到更加准确的沉降结果,本文采用了Peck经验公式与Verruijt复变函数相结合预测地表沉降的理论研究办法,并考虑了不同施工参数对地表沉降的影响。同时,采用数值计算的方法,对理论预测进行验证。其次,第二阶段对轨道沉降进行预测,基于连续弹性点支承梁模型的路基不均匀沉降引起轨道沉降的计算方法,将地表沉降作为轨道沉降的非线性边界条件,对轨道沉降进行预测。并同样考虑了相应施工参数对轨道沉降的影响。然后,基于轨道高低平顺性,提出了针对不同施工参数的轨道沉降控制标准,并制定了相应的沉降控制措施。最后,将两阶段分析法应用于福州地铁1号线罗汉山站~福州火车站站盾构下穿有砟铁路轨道段,与监测数据进行对比分析,验证了本文轨道沉降研究方法的可靠性。并得到了如下主要结论:(1)在施工参数改变的情况下,Peck公式拟合Verruijt复变函数得到的地表沉降曲线相关系数均在0.98以上,证明此理论办法预测地表沉降具有较高的适应性。且该预测方法可将土体弹性模量E和泊松比μ考虑在内,较传统Peck公式通过经验给定的沉降槽宽度系数i,预测的地表沉降具有更高的可靠性。(2)盾构隧道施工引起的地表沉降主要发生在盾构开挖掌子面邻近前、盾构通过期间及盾尾通过后三个阶段。地层损失率和土体泊松比对地表沉降量的影响较大,对沉降槽宽度影响较小;隧道埋深对地表沉降量和沉降槽宽度的影响均较大。(3)通过将地表的不均匀沉降作为轨道沉降的非线性边界条件,推导出了下穿有砟铁路盾构隧道施工引起的轨道沉降解析解。得到相关施工参数对轨道沉降影响,与其对路基沉降影响的规律类似,并对钢轨刚度和道砟刚度的取值提供了相关参考建议。(4)将本文的两阶段分析法,应用于福州地铁1号线相关工程,得到的预测与现场监测的轨道沉降幅值,误差在8%以内。验证了采用本文理论办法预测福州地铁软土地层轨道沉降的适应性和正确性。
[Abstract]:With the expansion of urban subway tunnel and high-speed railway construction, the project of subway tunnel passing through the existing railway line is becoming more and more common. The construction of the new tunnel will inevitably cause the settlement and deformation of the existing railway subgrade and track, which will affect the safe operation of the train. Therefore, it is necessary to study the law of settlement and deformation caused by the existing railway under the subway tunnel and the interaction mechanism between the tunnel subgrade and track, and to scientifically formulate the corresponding control method of track settlement in the course of tunnel construction. Firstly, in the first stage, the surface subsidence is predicted. In order to obtain more accurate settlement results, the Peck empirical formula and the Verruijt complex variable function are used to predict the surface subsidence. The influence of different construction parameters on surface subsidence is considered. At the same time, the method of numerical calculation is used to verify the theoretical prediction. Secondly, in the second stage, the track settlement is predicted. Based on the calculation method of uneven settlement of roadbed caused by uneven settlement of roadbed based on continuous elastic point support beam model, the surface settlement is regarded as the nonlinear boundary condition of track settlement. The settlement of the track is predicted. The influence of the corresponding construction parameters on the track settlement is also considered. Then, based on the high and low ride comfort of track, the control standard of track settlement for different construction parameters is put forward, and the corresponding settlement control measures are established. Finally, the two-stage analysis method is applied to the railway track section of the ballasted railway under shield tunneling in Luohanshan Station ~ Fuzhou Railway Station of Fuzhou Metro Line No. 1, and compared with the monitoring data, the reliability of the research method of track settlement in this paper is verified. The main conclusions are as follows: (1) the correlation coefficient of surface subsidence curve obtained by fitting Verruijt complex variable function with Peck formula is above 0.98, which proves that this theoretical method has high adaptability to predict surface subsidence. The elastic modulus E and Poisson's ratio 渭 can be taken into account in this method. Compared with the traditional Peck formula, the predicted surface settlement is more reliable than that of the traditional Peck formula. (2) the surface settlement caused by shield tunnel construction mainly occurs in front of the shield excavation face. Shield passing through and shield tail through the last three stages. The loss rate of formation and Poisson ratio of soil have a great influence on the surface settlement, but have little effect on the width of the settlement trough. The depth of tunnel has a great influence on the surface settlement and the width of settlement trough. (3) by taking the uneven settlement of the ground surface as the nonlinear boundary condition of track settlement, the analytical solution of track settlement caused by the construction of shield tunneling through ballasted railway is derived. The influence of relevant construction parameters on track settlement is similar to that of roadbed settlement, and the relevant reference suggestions are provided for the determination of rail stiffness and ballast stiffness. (4) the two-stage analysis method of this paper is presented. Applied to the relevant projects of Fuzhou Metro Line 1, the error of the prediction and monitoring of track settlement amplitude is less than 8%. The applicability and correctness of the theoretical method used in this paper to predict the track settlement of soft soil in Fuzhou Metro are verified.
【学位授予单位】：福建工程学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.43;U213.157

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