【作者】 李莹春；

【导师】 谷爱军；

【作者基本信息】 北京交通大学 ， 道路与铁道工程， 2010， 硕士

【摘要】 随着我国地铁的迅速兴建,地铁修建蔓延至城郊,新建地铁穿越大铁路股道、大铁路道岔区的穿越工程越来越多。而道岔是轨道结构中三大薄弱环节之一,现在大铁路的运输任务特别繁忙,在很多穿越施工中,铁路部门要求列车正常运营,并提出穿越施工零沉降的要求。本文以北京地铁9号线丰东～丰南区间盾构下穿丰台火车站的工程为依托,运用ABAQUS有限元分析软件,建立了道岔-双线隧道三维有限元静力模型,分析了盾构隧道开挖方式的不同,对道岔结构安全性(评价指标是道岔结构的变形和道岔静态几何形位,包括道岔沉降、钢轨横向位移、高低、水平、三角坑、轨向和轨距)的影响。主要是从以下几个方面进行分析：(1)进行左线隧道开挖,分析道岔几何形位的变化,得到左线隧道开挖引起的道岔结构几何形位的变化曲线；(2)由于道岔是不对称结构,故进行右线隧道开挖,对比分析左、右线隧道开挖引起的道岔几何形位的变化；(3)在左线隧道已开挖的基础上,进行右线隧道开挖,分析因右线隧道开挖引起的的土体二次扰动对道岔几何形位的影响；(4)进行双线隧道同时开挖的模拟,分析其对道岔几何形位的影响；(5)总结盾构隧道穿越道岔结构所采用的安全控制措施,并通过地基预加固、扣轨加固、改变同步注浆强度,验证各种安全控制措施对道岔几何形位的影响控制的有效性。更多还原

【Abstract】 Along with the rapid construction of the subways, the subway construction has been spread to the surburbs; the crossing projects of the new subway tunnel crossing railway track or railway turnout area are confronted more and more. The turnout is the one of the three weak links of the track structure. Moreover, the railway transport is particularly busy and regular operating of trains and zero track settlement are demanded by the railway department in many crossing projects.In this paper, supported by the crossing project of the shield driven tunnel of Fengtai East Road to Fengtai South Street in No.9 line of Beijing subway shield beneath the Fengtai railway station, the finite element analysis software ABAQUS was used to establish the static 3-D finite element model of the turnout-Double subway Tunnel. The Influence of different excavation methods of the shield tunnel to the safety of turnout structure was studied, the evaluation indexes involved are the deformation of turnout structure and turnout static geometry, including turnout settlement, rail lateral displacement, longitudinal level, track cross level, track twist, track alignment and track gauge. The analysis of the influence above was made on the following aspects:(1) As for the left line of the shield tunnel excavation, the change of turnout geometry were analyzed to obtain the curve of the change of turnout geometry due to the left line tunnel excavation; (2) For the turnout is asymmetric, the left and right line of the tunnel excavation turnout caused by changes in turnout geometry were compared; (3) As the right line of the shield tunnel was excavated on the basis of the left line of the shield tunnel excavation, the influence of secondary disturbances of soil to the turnout geometry was investigated; (4) The influence of simultaneous excavation of Double subway tunnel on turnout geometry was also studied; (5) The security control measures of shield tunnel crossing the turnout structure were summarized and the effectiveness of pre-reinforcing the foundation, trengthening of turnout with I iron track-locking and changing the intensity of the grouting, to enhance the impact of the turnout geometry was verified.更多还原