摘要
利用显式有限元有限差分方法研究了局部突出平台状粘弹性场地的地形影响,比较了高宽比不同、体波入射角度不同时谱特性的差异,分析了相邻地形的存在对地面运动谱特性的影响。研究结果表明,对于局部突出地形,高宽比和体波入射角度对地震动的谱特性有较大影响,入射角度的影响更为显著;相邻地形的存在使地面运动进一步放大。
An explicit finite element-finite difference method is performed to evaluate the part-projecting topography effects on the seismic response of visco-elastic sites.The different spectrum properties under the conditions of different high-width ratios(H/L value) and different angles of incidence are compared,the effect of multi-mesa is analysed also,The results show that for presence of part-projecting topography,the H/L value and the direction of incident waves significantly affect the spectrum property,the effect of the direction of the incident wave is especially remarkable,the presence of multi-mesa also increases the amplification effect of sites.
引文
[1]李小军,廖振鹏,关慧敏.粘弹性场地地形对地震动影响分析的显式有限元有限差分方法[J].地震学报.1995,17(3):362-369.
[2]廖振鹏,刘晶波.离散网格中的弹性波动(1)[J].地震工程与工程振动.1986,6(2):1-16.
[3]刘晶波,廖振鹏.离散网格中的弹性波动(2)[J].地震工程与工程振动.1989,9(2):1-11.
[4]刘晶波,廖振鹏.离散网格中的弹性波动(3)[J].地震工程与工程振动.1990,10(2):1-10.
[5]李小军.非线性场地地震反应分析方法的研究[D].国家地震局工程力学研究所博士学位论文.1993.
[6]陈丙午.不规则地形对地震动及震害的影响[J].地震工程与工程振动.1982,2(1):12-20.
[7]D Assimaki,G Gazetas.Soil and topographic amplification oncanyon banks and the 1999 Athens Earthquake[J].JEE.,2004,8(1):1-43.
[8]D M Boore.The Effect of Simple Topography on SeismicWaves;Implicate on for the Acceleration Recorded at PacoimaDam.San Fernando Valley California[J].BSSA.,1973,63(5):1603-1609.
[9]Lee V W.A note on scattering of elastic plane waves by ahemispherical canyon[J].Soil Dynamics and Earthquake Engi-neering,1982,1(3):122-129.
[10]Liu D K,Han F.Scattering of plane SH-wave by a cylindri-cal canyon of arbitrary shape in anisotopic media[J].ACTAMechanica Sinica,1990,6(3):256-266.
[11]Louis Geli,Pierre-Yves Bard,Beatrice Jullien.The effectof topography on earthquake ground motion:A Review andNew Results[J].BSSA.,1988,78(1):42-63.
[12]Sanchez-Sesma F.Elementary solutions for the response ofa wedge-shaped medium to incident SH and SV waves[J].BSSA.,1990,80:737-742.
[13]Trifunac M D.Surface motion of a semi-cylindrical valley forincident plane SH waves[J].BSSA.,1971,61:1755-1770.
[14]Wong H L,Trifunac M D.Surface motion of a semi-ellipticalalluvial valley for incident plane SH waves[J].BSSA.,1974,64:1389-1408.