摘要
基于近场波动有限元方法并结合黏弹性人工边界条件,针对3D断层场地,通过求解等效二维场地地震响应,从而获得3D场地地震动输入的自由场响应,并将自由场响应转化为3D模型边界面上的等效节点力,从而建立含断层3D场地P波入射的倾斜输入方法。自由场算例验证所提方法具有较好精度,进而基于建立的输入方法,开展了跨断层隧道地震响应的数值模拟研究。数值模拟结果表明:在P波作用下,隧道跨断层部位处于拉、压、剪切的复杂受力状态,且断层处的隧道衬砌地震响应明显大于其他部位的地震响应;围岩的力学性质与断层的力学性质相差越大,断层处衬砌的地震响应放大越明显;断层处衬砌地震响应随断层深度的增加而增加。另外,跨断层隧道的地震响应受P波入射角度的影响较大,随P波入射角度的增加,断层处隧道衬砌的轴力、弯矩先增加后减小,而剪力具有逐渐减小的规律。
On the basis of the time-domain wave method coupling the explicit finite element method with the viscous-spring artificial boundary condition, the input seismic motion was converted into the equivalent nodal force acted on the viscous-spring artificial boundary condition. For the three-dimensional(3D) fault site, the free-field response of the 3D field model was obtained by solving the seismic response of the equivalent two-dimensional field model, and the free-field response was converted into the equivalent node force of the 3D model. Subsequently, the oblique-incidence input method of P waves was proposed for the 3D fault site in the study. The precision of the present approach was verified by half-space numerical examples. Finally, the proposed method was applied to investigate the influence of fault on the seismic response of a long lined tunnel through fault subjected to P waves. The numerical results indicate that the seismic response of tunnel lining near the fault is amplified greatly. The tunnel is in the complex stress state of tensile, compression and shear under P waves. The seismic response increases with the weakening of the mechanical properties of the fault, and the depth of fault also influences the seismic response of the tunnel. With increasing the incident angle of earthquake waves, the axial force and bending moment of the tunnel lining near the fault increase first and then decrease. However, the shear force gradually decreases with increasing the incident angle.
作者
赵密
欧阳文龙
黄景琦
杜修力
赵旭
ZHAO Mi;OUYANG Wen-long;HUANG Jing-qi;DU Xiu-li;ZHAO Xu(The Key Laboratory of Urban Security and Disaster Engineering,Ministry of Education,Beijing University of Technology,Beijing 100124,China;School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第9期3645-3655,共11页
Rock and Soil Mechanics
基金
国家重点基础研究发展计划（973计划）（No.2015CB057902）
国家自然科学基金青年基金项目（No.51608015）
中央高校基本科研业务费专项资金资助项目（No.FRF-TP-17-074A1）~~
关键词
隧道
断层
P波
时域显式有限元
黏弹性人工边界
rock tunnels
fault
P waves
time-domain wave method
viscous-spring artificial boundary condition
