隧道-滑坡平行体系变形机理的模型试验研究

发布时间：2019-05-21 18:00

【摘要】：研究目的:线路选线中经常遇到无法避绕的滑坡,当隧道走向与滑坡主滑方向一致时,称为隧道-滑坡平行体系,对隧道的施工、运营都可能造成严重威胁。目前对穿越滑坡的隧道还没有形成统一的认识计算理论。本文以隧道-滑坡平行体系为研究对象,通过模型试验,设置3个不同埋深的隧道模型,模拟隧道开挖过程,并在后部加载促使坡体蠕动,在隧道周围布置应变片对隧道的应变进行监测,在坡体表面特征位置布置百分表监控位移。研究结论:(1)应变测试表明:平行体系中,隧道埋深越大,隧道开挖后应力的释放对隧道顶部坡面的影响越小,随着埋深的增加,隧道的应变逐渐增大;(2)位移测试表明:基岩与滑坡交界处的水平位移最大,坡顶竖向位移最大的点位于隧道进口和基岩的中间部位;(3)对比发现:隧道-滑坡体系在滑体中伸入长度较小时,隧道受力模式更接近两端铰接的杆状受力结构;当伸入长度较大时,隧道的受力模式更接近于悬挑结构,隧道容易在基岩与滑体交界面位置产生应力集中;(4)本研究结论可为高速铁路穿越滑坡地区的设计和施工提供一定借鉴。
[Abstract]:Research purpose: landslide which can not be avoided is often encountered in line selection. When the direction of tunnel is consistent with the main slip direction of landslide, it is called tunnel-landslide parallel system, which may pose a serious threat to the construction and operation of tunnel. At present, there is no unified understanding and calculation theory for the tunnel passing through the landslide. In this paper, the parallel system of tunnel and landslide is taken as the research object. Through the model test, three tunnel models with different buried depths are set up to simulate the excavation process of the tunnel, and the slope body is peristaltic under the loading at the back of the tunnel. Strain gauges are arranged around the tunnel to monitor the strain of the tunnel, and a percentile is arranged to monitor the displacement at the characteristic position of the slope surface. The conclusions are as follows: (1) in the parallel system, the larger the buried depth of the tunnel is, the smaller the effect of stress release on the top slope of the tunnel is after excavation. With the increase of the buried depth, the strain of the tunnel increases gradually. (2) the displacement test shows that the horizontal displacement at the junction of bedrock and landslide is the largest, and the point with the largest vertical displacement at the top of the slope is located in the middle of the entrance of the tunnel and the bedrock; (3) it is found that the tunnel-landslide system extends into the sliding body with a small length, and the stress mode of the tunnel is closer to the rod-shaped stress structure hinged at both ends. When the extension length is large, the stress mode of the tunnel is closer to the overhanging structure, and the tunnel is easy to produce stress concentration at the interface between bedrock and slide body. (4) the conclusion of this study can provide some reference for the design and construction of high-speed railway passing through landslide area.
【作者单位】：中铁西北科学研究院有限公司;中国铁道科学研究院;兰州交通大学;
【基金】：铁道部科技研究开发计划重点课题(2010G018-C-3-1) 甘肃省交通建设科研项目(200813) 中国中铁股份公司科技开发计划(20160203)
【分类号】：U456

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