SEISMIC RESPONSE ANALYSIS OF MULTI-LAYERED TI SATURATED SITE SUBJECTED TO OBLIQUE INCIDENT SEISMIC WAVE
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摘要: 滨海地区的天然土体在长期的风化和沉积作用下，其水平模量往往会大于其竖向模量，表现出明显的横观各向同性（TI）饱和特性，目前还很少有针对地震波斜入射下TI饱和场地动力响应问题的研究。将HaskellThomson传递矩阵方法拓展到层状TI饱和半空间，求解了直角坐标系下两相介质的Biot动力平衡方程及孔隙流体运动方程，建立了层状TI饱和半空间传递矩阵，并结合地表边界条件求解了地震波斜入射下层状TI饱和场地自由场的时域反应。该文验证了提出方法的正确性，进而以CNTEWGXE波（0.3 g）作为输入地震动，研究了土体TI性质及饱和特性对场地加速度时程及反应谱的影响。结果表明：层状TI饱和场地和各向同性饱和场地地表的动力响应存在一定差异，TI参数的改变使得场地对地震波产生不同的滤波和放大效应；场地的饱和特性对地表的动力响应有重要影响，饱和多孔介质固液耦合作用对地震波具有削弱作用；地震波斜入射时地表加速度时程及反应谱响应小于其垂直入射时的响应，且入射角度对qP1波入射时的场地影响更明显。Abstract: Under long-term weathering and deposition, the horizontal modulus of natural soil in coastal areas is often greater than its vertical modulus, showing obvious transverse isotropic (TI) saturation characteristics. However, there are few studies on the dynamic response of TI saturated site. Haskell-Thomson transfer matrix method is extended to a layered TI saturated half space. First, Biot dynamic equilibrium equation and the pore fluid motion equation of two-phase medium in a rectangular coordinate system are solved. Then a layered TI saturated half-space transfer matrix is established. Finally, the time domain response of the free field of a layered TI saturated site under the oblique incidence of seismic waves is solved in combination with surface boundary conditions. The paper verifies the correctness of the proposed method, and then takes CNTWGXE wave (0.3 g) as input ground motion to study the influence of soil TI properties and saturation characteristics on the acceleration time history and the response spectrum of the site. Analytical results show that:the dynamic response of the layered TI saturated site and that of the isotropic saturated site are different, and changes in TI parameters cause the site to have different filtering and amplification effects on seismic waves. The saturation characteristics of the site have an important influence on the dynamic response of the surface, and the solid-liquid coupling of saturated porous media has a weakening effect on seismic wave. The peak values of surface acceleration and response spectrum are less than those of the oblique incidence, and the incident angle has more obvious impact on the site for qP1 wave.
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Keywords:
- free field /
- transversely isotropic /
- saturated porous medium /
- transfer matrix /
- oblique incidence /
- layered site
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[1] Fu J, Liang J W, Todorovska M I, et al. Soil-structure system frequency and damping:estimation from eigenvalues and results for a 2D model in layered half-space[J]. Earthquake Engineering and Structural Dynamics, 2018, 47:2055-2075.
[2] Lu X, Tian Y, Wang G, et al. A numerical coupling scheme for nonlinear time history analysis of buildings on a regional scale considering site-city interaction effects[J]. Earthquake Engineering & Structural Dynamics, 2018, 47(13):2708-2725.
[3] Haskell N A. The dispersion of surface waves on multilayered media[J]. Bulletin of the Seismological Society of America, 1953, 43(1):86-103.
[4] Thomson W T. Transmission of elastic waves through a stratified soil medium[J]. Journal of Applied Physics, 1950, 21(2):89-93.
[5] Kausel E, Roësset J M. Stiffness matrices for layered soils[J]. Bulletin of the Seismological Society of America, 1981:1743-1761.
[6] Wolf J P, Obernhuber P. Free-field response from inclined SH-waves and Love-waves[J]. Earthquake Engineering and Structural Dynamics, 1982, 10(6):823-845.
[7] 于国友, 何玉敖, 梁建文. 层状半空间场地对地震波的放大作用[J]. 天津大学学报, 1993(4):79-85. Yu Guoyou, He Yuao, Liang Jianwen. Amplification of layered soil to seismic waves[J]. Journal of Tianjin University, 1993 (4):79-85. (in Chinese)
[8] 梁建文, 巴振宁. 三维层状场地的精确动力刚度矩阵及格林函数[J]. 地震工程与工程振动, 2007(5):7-17. Liang Jianwen, Ba Zhenning. Exact dynamic stiffness matrices of 3 -D layered site and its Green's functions[J]. Journal of Earthquake Engineering and Engineering Vibration, 2007(5):7-17. (in Chinese)
[9] Deresiewicz H, Rice J T. The effect of boundaries on wave propagation in a liquid-filled porous solid:III. Reflection of plane waves at a free plane boundary (general case)[J]. Bulletin of the Seismological Society of America, 1962, 52(3):595-625.
[10] Deresiewicz H. The effect of boundaries on wave proagation in a liquid-filled porous solid:VII. Surface waves in a half-space in the presence of a liquid layer[J]. Bulletin of the Seismological Society of America, 1964, 54(1):425-430.
[11] Yang J, Sato T. Interpretation of seismic vertical amplification at an array site[J]. Bulletin of the Seismological Society of America, 2000, 90(2):275-284.
[12] Lin C H. Wave propagation in a poroelastic half-space saturated with inviscid fluid[D]. Los Angeles:University of Southern California, 2002.
[13] 李伟华, 赵成刚, 杜楠馨. 软弱饱和土夹层对地铁车站地震响应的影响分析[J]. 岩土力学, 2010, 31(12):3958-3963 , 3970. Li Weihua, Zhao Chenggang, Du Nanxin. Analysis of effects of saturated soft interlayer on seismic responses of metro station[J]. Rock and Soil Mechanics, 2010, 31(12):3958-3963, 3970. (in Chinese)
[14] 巴振宁, 梁建文. 流体饱和半空间中埋置球面P1, P2和SV波源动力格林函数[J]. 工程力学, 2016, 33(5):34-43. Ba Zhenning, Liang Jianwen. Dynamic Green's functions of spherical P1, P2 and SV sources embedded in a watersaturated half-space[J]. Engineering Mechanics, 2016, 33(5):34-43. (in Chinese)
[15] 陈镕, 陈竹昌, 薛松涛, 等. 横观各向同性层状场地对入射SH波的响应分析[J]. 上海力学, 1998(3):213-220. Chen Rong, Chen Zhuchang, Xue Songtao, et al. The response analysis of transversely isotropic elastic strata to incident SH waves[J]. Shanghai Journal of Mechanics, 1998 (3):213-220. (in Chinese)
[16] 薛松涛, 陈镕, 秦岭, 等. 横观各向同性层状场地的动力边界条件[J]. 岩石力学与工程学报, 2001, 20(1):65-69. Xue Songtao, Chen Rong, Qin Ling, et al. The dynamic boundary conditions of transversely isotropic stratIfied media[J]. Chinese Journal of Rock Mechanics and Engineering, 2001, 20(1):65-69. (in Chinese)
[17] Schmitt D P. Acoustic multipole logging in transversely isotropic poroelastic formations[J]. Journal of the Acoustical Society of America, 1989, 86(6):2397-2421.
[18] Sharma M D. Wave propagation in anisotropic liquid-saturated porous solids[J]. Acoustical Society of America Journal, 1991, 90(2):1068-1073.
[19] Liu Y, Liu K, Tanimura S. Wave propagation in transversely isotropic fluid-saturated poroelastic media[J]. Jsme International Journal, 2002, 45(3):348-355.
[20] 陈胜立, 张建民. 横观各向同性饱和地基轴对称Biot固结问题的解析解[J]. 岩土工程学报, 2002(1):26-30. Chen Shengli, Zhang Jianmin. An analysis of axisymmetric consolidation for transversely isotropic saturated soils[J]. Chinese Journal of Geotechnical Engineering, 2002 (1):26-30. (in Chinese)
[21] 陆建飞, 周慧明, 刘洋. 横观各向同性层状饱和土动力问题的反射、透射矩阵方法[J]. 岩土力学, 2018, 39(6):2219-2225. Lu Jianfei, Zhou Huiming, Liu Yang. Reflection transmission matrix method for dynamic response of transversely isotropic multilayered saturated soil[J]. Rock and Soil Mechanics, 2018, 39(6):2219-2225. (in Chinese)
[22] Biot M A. Theory of propagation of elastic waves in fluid-saturated porous solid. I. Low-frequency range[J]. Journal of the Acoustical Society of America, 1956, 28:168-178.
[23] Ba Z, Liang J. Fundamental solutions of a multi-layered transversely isotropic saturated half-space subjected to moving point forces and pore pressure[J]. Engineering Analysis with Boundary Elements, 2017, 76:40-58.
[24] 宋佳, 许成顺, 杜修力, 等. 基于精细时程积分的u-p格式饱和两相介质动力问题的显-显式时域算法[J]. 工程力学, 2017, 34(11):9-17. Song Jia, Xu Chengshun, Du Xiuli, et al. A temporal explicit-explicit algorithm based on the precise time-integration for solving the dynamic problems of fluid-saturated porous media in u-p form[J]. Engineering Mechanics, 2017, 34(11):9-17. (in Chinese)
[25] 李志远, 李建波, 林皋, 等. 饱和层状地基条形基础动刚度的精细积分算法[J]. 工程力学, 2018, 35(6):15-23. Li Zhiyuan, Li Jianbo, Lin Gao, et al. Precise integration method for dynamic stiffness of strip foundation on saturated poroelastic soil[J]. Engineering Mechanics, 2018, 35(6):15-23. (in Chinese)
[26] Wolf J P. Dynamic soil-structure interaction[M]. Englewood Cliffs:Prentice Hall, 1985.
[27] 梁建文, 潘坤, 巴振宁. 层状横观各向同性场地地震反应分析[J]. 地震工程与工程振动, 2017, 37(4):1-14. Liang Jianwen, Pan Kun, Ba Zhenning. Seismic response analysis of a multi-layered transversely isotropic half space[J]. Earthquake Engineering and Engineering Dynamics, 2017, 37(4):1-14. (in Chinese)
[28] 刘方成, 姚玉文, 吴孟桃, 等. 橡胶砂垫层在不同类别场地上的减震效应研究[J]. 地震工程与工程振动, 2019, 39(1):128-137. Liu Fangcheng, Yao Yuwen, Wu Mengtao, et al. Isolating effects of rubber sand mixture cushion at different categorIzed sites[J]. Earthquake Engineering and Engineering Dynamics, 2019, 39(1):128-137. (in Chinese)
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