基于相对位移的偏压小净距隧道动力稳定性  

Dynamic stability of small-spacing tunnels subjected to unsymmetrical pressure based on relative displacement

作　　者：李君君[1] 何本国[2] 万涛[1] 刘训臣[1] 

机构地区：[1]石家庄铁路职业技术学院,河北石家庄050041 [2]西南交通大学土木工程学院,四川成都610031

出　　处：《四川建筑科学研究》2016年第6期69-74,共6页Sichuan Building Science

基　　金：国家自然科学基金资助项目(51178399);河北省教育厅资助课题(Z2015048)

摘　　要：动力灾害作用下,地下建筑工程结构稳定性一直是工程界、学术界关注的热点问题。以在建石家庄市曹家庄小净距隧道为依托,建立了三维有限差分动力模型,采用相对位移的方法研究了最大地震抗震设计动荷载作用下隧道结构的变形特性、力学响应以及围岩能量集聚。研究表明:水平地震荷载作用下,隧道发生挤让、椭圆化的变形趋势;由于地形偏压作用,相邻两隧道表现出不同步变形现象;能量密度大于2 300 J/m3区域主要集聚在中夹岩柱和深埋侧隧道的边墙。深埋侧隧道弯矩明显大于浅埋侧隧道,最大弯矩出现在深埋侧右墙脚,该部位安全系数稍小于规范要求,为关键控制部位。Stability of underground building has been a special issue in fields of engineering and academy when subjected to dynamic impact hazard. By taking Caojiazhuang small-spacing tunnels in Shijiazhuang city as an example, three-dimensional finite deference modelling was performed to investigate the displacement characteristics, mechanical response as well as energy concentration of surrounding rock under maximum design earthquake by means of relative displacement. Inspection of results reveals that the racking/ ovaling deformation takes place on account of horizontal seismicity. Due to unsymmetrical pressure of terrain the asynchronous deformation appears for the twin small-spacing tunnels. The high-energy zone more than 2 300 J/m^3 concentrates at the interval pillar and side-wall of depth lateral. The bending moment of deep-buried tunnel lining is more than that of the shallow tunnel. The maximum bending moment appears at the wall-footing,which is slightly less than the requirement and is referred to be the critical part of safety.

关 键 词：最大地震抗震设计 小净距隧道 动力响应 能量集聚 相对位移 

分 类 号：U452[建筑科学—桥梁与隧道工程]