摘要
近年来,运营期隧道发生病害的比例逐年提高,其中以洞口处滑坡对隧道的破坏最为严重,对陆路交通安全运营造成严重威胁。通过模型试验,设置桥隧过渡段支撑方式,以连续逐级加载的形式模拟坡体蠕滑变形,对平行体系中隧道的受力模式及破坏过程进行研究。结果表明:在桥隧过渡段支撑作用下,位于滑体内隧道的变形特征与梁式结构一致,可将该段隧道简化为梁式结构;隧道轴向上位于滑带处隧道所受的滑坡推力最大,此处极易发生剪切错断;截面上,隧道拱部所受到的应力比隧道底部大,同时隧道拱部受拉,底部受压,在隧道受拉与受压的过渡区域形成拉压中性区;隧道坡坏的位置位于滑带附近,且隧道拱部首先产生剪切裂缝,随后向边墙扩展,最后裂缝贯通到隧道底部,导致隧道整体破坏。
In recent years, the proportion of tunnel defects in the operation period has been increasingand the landslide at the entrance of the tunnel is the greatest damage, posing a serious threat to the safeoperation of land traffic. Through model test and setting up supporting system in transition sections ofbridge and tunnel, the influence of the creep deformation of the slope body on the stress mode and thefailure process of the tunnel in the parallel system are studied by means of continuous step by steploading. The results show that under the support of the bridge and tunnel transition sections, thedeformation characteristics of the tunnel in the sliding body are the same as those of the beam typestructure, and the tunnel can be simplified as a beam type structure; the axial tunnel contact with thesliding zone is subjected to the maximum landslide thrust, and the shear fault tends to occur here; thestress on the arch of a tunnel on the cross section is larger than the bottom of the tunnel, at the sametime, the arch of the tunnel is pulled and the bottom is pressed, the tension and pressure neutral zone isformed in the transition section between tension and compression in the tunnel; the position of the tunnelslope is located near the sliding zone, and shear cracks first appear in the tunnel arc and then extend tothe side wall, and finally the cracks run through to the bottom of the tunnel, causing complete tunnel failure.
作者
赵金
吴红刚
牌立芳
李玉瑞
ZHAO Jin;WU Hong-gang;PAI Li-fang;LI Yu-rui(College of civil engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;China Northwest Research Institute Co.,Ltd.of CREC,Lanzhou 730000,China;China Railway Landslide Engineering Laboratory,Lanzhou 730000,China;Western Environmental Geotechnical and Site Rehabilitation Technology Engineering Laboratory,Lanzhou 730000,China)
出处
《铁道标准设计》
北大核心
2018年第11期129-133,138,共6页
Railway Standard Design
基金
中铁科研院科研项目(2017-KJ008-Z008-XB)
关键词
桥隧过渡段
平行体系
梁式结构
中性区
Bridge transition section
Parallel system
Beam structure
Neutral zone
