SV波斜入射下凸起地形对地震动特性的影响分析
|
摘要
针对10种不同坡角的凸起地形,采用基于透射边界的有限元-有限差分计算方法,研究了局部凸起在SV波斜入射时,地震动峰值加速度放大倍数和反应谱谱比随入射角度的变化规律。结果表明:(1)地震波以一定的角度斜入射时,地表大部分观测点的峰值加速度放大倍数大于垂直入射的情况;(2)在计算模型宽高比一定的情况下,最不利入射角度与坡角有一定关系,且地表最不利位置随坡角增大由凸起台地边缘向中心移动;(3)入射角度对凸起地形地震反应谱特性的影响十分显著,不但影响谱比的幅值,也影响谱比曲线的形状,斜入射时各关键节点大部分周期点的谱比值大于垂直入射,入射角度对反应谱中的高频成分影响较为显著,而对长周期成分影响不大。
In this paper, we studied the impact of incident angle of seismic wave on the peak ground acceleration(PGA) and response spectrum of ground motion of the topography by the finite element-finite difference calculation method based on the transmission boundary, in which 150 working conditions from 10 terrains were analyzed. The results show that:(1) when the seismic wave is obliquely incident at a certain angle, the peak acceleration magnification of most observation points on the surface is basically larger than that of the vertical incident;(2) in the case of calculating the aspect ratio of the model, the most unfavorable incidence angle has a certain relationship with the slope angle, and the most unfavorable position of the surface changes with the slope angle from the edge of the raised platform to the center;(3) the influence of the incident angle on the seismic response spectrum of the raised terrain is very significant, which affects not only the amplitude of the spectral ratio, but also the the shape of the spectral curve. The spectral ratio of most of the periodic nodes is larger than that of the vertical incident at the oblique incidence, and the incident angle has a significant effect on the high frequency components in the response spectrum, but not on the long-period component.
In this paper, we studied the impact of incident angle of seismic wave on the peak ground acceleration(PGA) and response spectrum of ground motion of the topography by the finite element-finite difference calculation method based on the transmission boundary, in which 150 working conditions from 10 terrains were analyzed. The results show that:(1) when the seismic wave is obliquely incident at a certain angle, the peak acceleration magnification of most observation points on the surface is basically larger than that of the vertical incident;(2) in the case of calculating the aspect ratio of the model, the most unfavorable incidence angle has a certain relationship with the slope angle, and the most unfavorable position of the surface changes with the slope angle from the edge of the raised platform to the center;(3) the influence of the incident angle on the seismic response spectrum of the raised terrain is very significant, which affects not only the amplitude of the spectral ratio, but also the the shape of the spectral curve. The spectral ratio of most of the periodic nodes is larger than that of the vertical incident at the oblique incidence, and the incident angle has a significant effect on the high frequency components in the response spectrum, but not on the long-period component.
引文
丁海平,于彦彦,郑志法,2017.P波斜入射陡坎地形对地面运动的影响.岩土力学,38(6):1716-1724,1732.
杜修力,陈维,李亮等,2007.斜入射条件下地下结构时域地震反应分析初探.震灾防御技术,2(3):290-296.
郝明辉,张郁山,2014.凸起地形对地震动特性的影响.地震学报,36(5):883-894.
郝明辉,张郁山,2015.相邻地形对地震动特性的影响分析.中国地震,31(4):656-667.
金丹丹,陈国兴,董菲蕃,2014.多地貌单元复合场地非线性地震效应特征二维分析.岩土力学,35(6):1818-1824.
李山有,廖振鹏,2002.地震体波斜入射情形下台阶地形引起的波型转换.地震工程与工程振动,22(4):9-15.
李小军,廖振鹏,关慧敏,1993.粘弹性场地地形对地震动影响分析的有限元-有限差分方法.地震学报,17(3):362-369.
李英民,王丽萍,赵耀,2010.坡地地形对竖向地震动反应谱特性的影响分析.地震工程与工程振动,30(5):156-161.
梁建文,张彦帅,Lee V.W.,2006.平面SV波入射下半圆凸起地形地表运动解析解.地震学报,28(3):238-249.
刘晶波,1996.局部不规则地形对地震地面运动的影响.地震学报,18(2):239-245.
荣棉水,李小军,卢滔,2007.局部地形对入射P波谱特性的影响分析.西北地震学报,29(4):297-302.
王琴,陈隽,李杰,2008.斜入射地震波作用下地下管线的地震反应分析.华中科技大学学报(城市科学版),25(4):283-286.
张伯艳,陈厚群,苏克忠,1999.地震波的入射方向对河谷岸坡放大系数的影响.水利水电技术,30(9):42-44.
张季,2009.弹性层状场地上凸起地形的出平面地震响应分析.天津:天津大学.
张郁山,赵凤新,2014.基于小波函数的地震动反应谱拟合方法.土木工程学报,47(1):70-81.
周红,高孟潭,俞言祥,2010.SH波地形效应特征的研究.地球物理学进展,25(3):775-782.
朱传彬,张建经,2014.SH波斜入射盆地地表的时域非线性地震反应分析.地下空间与工程学报,10(4):834-841.
Zhou H.,Chen X.F.,2006.A new approach to simulate scattering of SH waves by an irregular topography.Geophysical Journal,164(2):449-459.
杜修力,陈维,李亮等,2007.斜入射条件下地下结构时域地震反应分析初探.震灾防御技术,2(3):290-296.
郝明辉,张郁山,2014.凸起地形对地震动特性的影响.地震学报,36(5):883-894.
郝明辉,张郁山,2015.相邻地形对地震动特性的影响分析.中国地震,31(4):656-667.
金丹丹,陈国兴,董菲蕃,2014.多地貌单元复合场地非线性地震效应特征二维分析.岩土力学,35(6):1818-1824.
李山有,廖振鹏,2002.地震体波斜入射情形下台阶地形引起的波型转换.地震工程与工程振动,22(4):9-15.
李小军,廖振鹏,关慧敏,1993.粘弹性场地地形对地震动影响分析的有限元-有限差分方法.地震学报,17(3):362-369.
李英民,王丽萍,赵耀,2010.坡地地形对竖向地震动反应谱特性的影响分析.地震工程与工程振动,30(5):156-161.
梁建文,张彦帅,Lee V.W.,2006.平面SV波入射下半圆凸起地形地表运动解析解.地震学报,28(3):238-249.
刘晶波,1996.局部不规则地形对地震地面运动的影响.地震学报,18(2):239-245.
荣棉水,李小军,卢滔,2007.局部地形对入射P波谱特性的影响分析.西北地震学报,29(4):297-302.
王琴,陈隽,李杰,2008.斜入射地震波作用下地下管线的地震反应分析.华中科技大学学报(城市科学版),25(4):283-286.
张伯艳,陈厚群,苏克忠,1999.地震波的入射方向对河谷岸坡放大系数的影响.水利水电技术,30(9):42-44.
张季,2009.弹性层状场地上凸起地形的出平面地震响应分析.天津:天津大学.
张郁山,赵凤新,2014.基于小波函数的地震动反应谱拟合方法.土木工程学报,47(1):70-81.
周红,高孟潭,俞言祥,2010.SH波地形效应特征的研究.地球物理学进展,25(3):775-782.
朱传彬,张建经,2014.SH波斜入射盆地地表的时域非线性地震反应分析.地下空间与工程学报,10(4):834-841.
Zhou H.,Chen X.F.,2006.A new approach to simulate scattering of SH waves by an irregular topography.Geophysical Journal,164(2):449-459.