盾构下穿高速公路扶壁式挡土墙的变形分析

发布时间：2019-05-27 04:58

【摘要】：研究目的:地铁盾构施工土体挖除、管片和二衬设置对土层的扰动会导致地表挡墙的变形,尤其是挡墙沉降和倾斜,对上部公路的运营产生不利影响。论文用Midas/GTS模拟北京地铁6号线下穿通燕高速公路北皇木厂桥段,分析采用盾构法先后施工左右线隧道引起的桥间路基扶壁式挡墙的变形变化特征。研究结论:(1)挡墙竖向位移变形与挡墙到两侧桥台距离之间呈现"中间大、两边小"的抛物线型变化趋势;(2)挡墙沉降的大部分产生在先施工左线过程中,后施工右线中则较小,说明挡墙沉降主要发生在第一次盾构穿越施工时,因此在第一次施工过程中应该适当减小推进长度;(3)挡墙变形与盾构隧道的位置距离呈负相关的关系,挡墙的倾斜度表现为盾构施工正上方时倾斜度出现极值,同截面极值点两侧逐渐减小;(4)该研究成果可为地铁盾构穿越上部挡墙结构安全性评估工作提供指导。
[Abstract]:Research purpose: the disturbance of soil layer caused by segment and second lining in shield construction of subway will lead to the deformation of surface retaining wall, especially the settlement and tilt of retaining wall, which will have adverse effects on the operation of upper highway. In this paper, Midas/GTS is used to simulate the section of Bei Huang Muchang Bridge of Tongyan Expressway under Beijing Metro Line 6, and the deformation and variation characteristics of subgrade supporting retaining wall between bridges caused by shield method are analyzed. The conclusions are as follows: (1) there is a parabola change trend between the vertical displacement deformation of the retaining wall and the distance from the retaining wall to both sides of the bridge platform, which is "large in the middle and small on both sides"; (2) most of the settlement of the retaining wall occurs in the process of the left line of the first construction, but smaller in the right line of the construction, which indicates that the settlement of the retaining wall mainly occurs during the first shield crossing construction, so the propulsion length should be properly reduced in the first construction process; (3) there is a negative correlation between the deformation of the retaining wall and the position distance of the shield tunnel. The inclination of the retaining wall appears extreme value when the shield is constructed directly above the shield construction, and decreases gradually on both sides of the extreme point of the same section. (4) the research results can provide guidance for the safety evaluation of subway shield passing through the upper retaining wall.
【作者单位】：北京交通大学;
【基金】：中央高校基本科研业务费专项资金资助(2014JBZ012)
【分类号】：U455.43;U417.11

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