穿越次级断层隧道地震动力响应及减震层效果分析  

Analysis on Seismic Dynamic Response and Effect of Shock Absorption Layer of Tunnels Passing Through the Secondary Fault

作　　者：王芳其[1] WANG Fangqi WANG Fangqi

机构地区：[1]招商局重庆交通科研设计院有限公司,重庆400067

出　　处：《公路交通技术》2018年第2期68-74,共7页Technology of Highway and Transport

摘　　要：为研究地震动荷载作用下次级断层对隧道衬砌应力、变形及加速度等动力响应的影响,找出穿越次级断层隧道结构抗震设防的思路及重点部位,以高烈度区典型穿越次级断层隧道为依托,通过有限差分软件FLAC3D对隧道穿越次级断层的动力响应进行计算分析,并建立在隧道初支及二衬之间设置6 cm,8 cm,10 cm三种厚度减震层的计算模型,对比分析减震层厚度与减震效果的关系。计算结果表明:次级断层与隧道相交位置沿轴向前后各20 m范围的衬砌地震动力响应有明显放大,为抗震设防重点位置;设置减震层能够明显减小隧道衬砌位移及应力响应,但随着减震层厚度的增加,衬砌加速度响应有所增加,建议穿越次级断层隧道采用厚度为6 cm^8 cm的减震层为宜。研究成果能够为穿越次级断层隧道的抗震设防提供参考。In order to study the influence of secondary fault on the dynamic responses of tunnel linings such as stress,deformation,and accelerated speed under the load effect of seismic oscillation,and to find out the train of thought and the important parts for earthquake fortification of tunnel structure passing through the secondary fault,relying on the typical tunnel passing through the secondary fault in highly seismic region,the dynamic response of tunnel passing through the secondary fault is calculated and analyzed with FLAC3D,the finite difference software.Besides,the calculation models for shock absorption layers with three different thicknesses,respectively 6cm,8cm and 10cm,are built between the primary supporting and second lining of tunnel so as to conduct a comparative analysis on the relationship between thickness of shock absorption layer and its effect.The calculation results show that the seismic dynamic response of the lining within 20m along the axis in front and at back of the place where the secondary fault and tunnel crosses is significantly enlarged,so it is the important part for earthquake fortification.Setting up shock absorption layer can significantly reduce the displacement and stress of tunnel lining.However,with the increase of thickness of shock absorption layer,the accelerated speed response of lining increases.It is recommended that the tunnels passing through the secondary fault adopt a shock absorption layer 6cm to 8cm in thickness.The research results can provide reference for earthquake fortification of tunnels passing through the secondary fault.

关 键 词：隧道工程 地震动力响应 减震层 次级断层 动力有限差分法 

分 类 号：U452.28[建筑科学—桥梁与隧道工程]