Taking the group-piles foundation of a large deep-water bridge as a study object, its nonlinear calculation model considering hydrodynamic effect and pile-soil interaction was built. The strong near-field and far-field earthquake records were taken as inputs, the dynamic response and damage characteristics of the foundation under different water depths were analyzed. The results showed that the dynamic responses of the foundation under near-field earthquakes are larger than those under far-field earthquakes; the maximum increments of shear force, moment, and displacement appear at different depths beneath the erosion line, while those of axial force appear at the pile top, the maximum increments of moment, shear force, displacement and axial force are 150.6%, 227.2%, 333.4% and 64.2%, respectively; under near-field earthquakes, the pier bottom and pile top are main vulnerable positions, the damage indexes of the pile top are 0.19 and 0.40, respectively under peak ground accelerations (PGAs) of 0.38g and 0.6g; the damage level and range increase with increase in earthquake intensity, and increase slightly with increase in water depth; under far-field earthquakes, the group-piles foundation is mainly in elastic state, due to the constraint effect of soil around piles, structural damage may occur at some junctions of soil layers with a certain depth, the damage level increases with increase in earthquake intensity and spreads to both ends. Comparisons showed that the dynamic responses and structural damage of the foundation under near-field earthquakes are significantly greater than those under far-field earthquakes; the impulse type near-field earthquakes have higher deformation and energy-dissipation demands, more attentions should be paid to the aseismic design of deep-water bridges, especially, the ductility design of their foundations.
江辉1，王志2，白晓宇1,曾聪1. 近、远场强震下深水桥梁群桩基础的非线性响应及损伤特性[J]. 振动与冲击, 2017, 36(24): 13-22.
JIANG Hui1, WANG Zhi2, BAI Xiao-yu1, ZENG Cong1. Nonlinear responses and damage characteristics for group-piles foundation of a deep-water Bridge under strong near-field and far-field earthquakes. JOURNAL OF VIBRATION AND SHOCK, 2017, 36(24): 13-22.
[1] Liaw C Y, Chopra A K. Dynamics of towers surrounded by water[J]. Earthquake Engineering and Structural Dynamics, 1974, 3(1): 33-49.
[2] Goyal A, Chopra A K. Earthquake analysis of intake-outlet towers including tower-water-foundation-soil interaction[J]. Earthquake Engineering and Structural Dynamics, 1989, 18(3): 325-344.
[3] Kimura M, Zhang F. Seismic evaluation of pile foundation[C]. Proceeding of 6th international Symposium, Numerical Models in Geomechanics. Montreal: Balkema, 1997: 545-548.
[4] 叶爱君，鲁传安．基于Pushover分析的群桩基础抗震性能分析方法[J]．土木工程学报，2010，43(2)：88-94.
YE Aijun, LU Chuanan. A seismic performance analysis approach based on pushover analysis for group pile foundations[J]. China Civil Engineering Journal, 2010, 43(2): 88-94.
[5] 江辉，李杰，杨庆山．考虑SSI 三种效应的桩基础RC 梁式桥抗震性能评估方法研究[J]．振动与冲击，2012，31(5)：65-72.
JIANG Hui, LI Jie, YANG Qingshan. A seismic performance evaluation method for a pile-foundation RC girder bridge considering three kinds of SSI effect[J]. Journal of Vibration and Shock, 2012, 31(5): 65-72.
[6] 魏凯，伍勇吉，袁万城，等．桥梁群桩基础-水耦合系统动力特性数值模拟[J]．工程力学，2010，28(增刊I) : 195-200．
WEI Kai, WU Yongji, YUAN Wancheng, et al. Numerical dynamic analysis for water-pile group bridge foundation interacted system[J]. Engineering Mechanics, 2010, 28(Supplement I): 195-200.
[7] 魏凯，袁万城．深水高桩承台基础地震动水效应数值解析混合算法[J]．同济大学学报：自然科学版，2013，41(3)：336-967．
WEI Kai, YUAN Wancheng. A numerical-analytical mixed method of hydrodynamic effect for Deep-water elevated pile cap foundation under earthquake[J]. Journal of Tongji University: Natural Science, 2012, 41(3): 336-967．
[8] 黄信，李忠献． 动水压力作用对深水桥墩地震响应的影响[J]．土木工程学报，2011，44(1)：65-73．
HUANG Xin, LI Zhongxian. Influence of hydrodynamic pressure on seismic response of bridge piers in deep water[J]. China Civil Engineering Journal, 2011, 44(1): 65-73.
[9] 宋波，李悦．高桩承台动水力简便计算方法[J]．北京科技大学学报，2011，33(4)：509-514．
SONG Bo, LI Yue. Simplified calculation method of hydrodynamic force for elevated pile caps[J]. Journal of University of Science and Technology Beijing, 2011, 33(4): 509-514．
[10] WEI K, YUAN W C, Bouaanani N. Experimental and numerical assessment of the three dimensional modal dynamic response of bridge pile foundations submerged in water[J]. Journal of Bridge Engineering, 2013, 18: 1032-1041.
[11] 黄麟，蒋劲松，姚红兵．庙子坪岷江大桥震后主墩裂缝的成因分析以及深水修复与加固[J]. 西南公路，2008，4：32-35．
HUANG Lin, JIANG Jingsong, YAO Hongbing. Crack cause analysis for the main pier of Miaoziping Min River Bridge after earthquake and repair and reinforcement under deep-water environment[J]. Southwest Highway, 2008, 4: 32-35．
[12] 黄信，李忠献．动水压力作用下深水桥墩非线性地震响应分析[J]．震灾防御技术，2010，5(3)：352-357．
HUANG Xin, LI Zhongxian. Nonlinear seismic response analysis of bridge pier in deep water under hydrodynamic pressure influence[J]. Technology for Earthquake Disaster Prevention, 2010, 5(3): 352-357.
[13] 孙治国，王东升，郭迅，等．钢筋混凝土墩柱等效塑性铰长度研究[J]．中国公路学报，2011，24(5)：56-64.
SUN Zhiguo, WANG Dongsheng, GUO Xun, et al. Research on equivalent plastic hinge length of reinforced concrete bridge column[J]. China Journal of Highway and Transport, 2011, 24(5) : 56-64．
[14] 杨红，白绍良．基于变轴力和定轴力试验对比的钢筋混凝土柱恢复力滞回特性研究[J]．工程力学，2003，20(6): 58-64.
Yang Hong, Bai Shaoliang. The hysteretic behavior of RC columns based on the contrasting tests under constant and varying axial forces[J]. Engineering Mechanics, 2003, 20(6): 58-64.
[15] 汪训流，陆新征，叶列平．变轴力下钢筋混凝土柱的抗震性能分析[J]．工业建筑，2007，37(12):71-75.
Wang Xunliu, Lu Xinzheng, Ye Lieping. Analysis of earthquake-resistent behaviors of RC columns under variable axial loads[J]. Industrial Construction, 2007, 37(12): 71-75.
[16] 燕斌，王志强，王君杰．桥梁桩基础计算中p-y曲线法与m法的对比研究[J]．结构工程师，2007，23(4): 62-68.
Yan Bin, Wang Zhiqiang, Wang Junjie. Study on comparison of p-y method and m-Method in computation of Bridge Pile Foundations[J]. Structural Engineers, 2007, 23(4): 62-68.
[17] 王宝喜．深水桥梁动水效应的改进算法及近场地震下的动力响应特性研究[D]．北京：北京交通大学，2015：57-91．
WANG Baoxi. Study on the improvement of hydrodynamic pressure calculation method and dynamic response feature of deep-water bridges excited by near-fault earthquake[D]. Beijing: Beijing Jiaotong University, 2015: 57-91.
[18] Morison J R, O'Brien M P, Johnson J W, and Schaaf S A. The force exerted by surface waves on piles[J]. Journal of Petroleum Technology, 1950, 2(5): 149-154.
[19] Goto H, Toki K. Vibration characteristics and a seismic design of submerged bridge piers[C]. Proceedings of the 3rd World Conference on Earthquake Engineering, New Zealand, 1965, 2, 107-122. 王君杰，赖伟，胡世德．深水高桩基础桥梁地震水动力效应分析[J]．同济大学学报：自然科学版，2011，39(5)：650-655．
WANG Junjie, LAI Wei, HU Shide. Seismic hydrodynamic effects on group-pile foundations with caps merged in water[J]. Journal of Tongji University: Natural Science, 2011, 39(5) : 650-655．
[20] Bhatta D D, Rahman M. On scattering and radiation problem for a cylinder in water of finite depth[J]. International Journal of Engineering Science, 2003, 41(9): 931-967.
[21] 庞于涛，袁万城，沈国煜，等．基于结构易损性分析的公路桥梁可靠度研究[J]．哈尔滨工程大学学报，2012，33(9)：1091-1096.
PANG Yutao, YUAN Wancheng, SHEN Guoyu, et al. Reliability analysis of highway bridges based on structural vulnerability analysis[J]. Journal of Harbin Engineering University, 2012, 33(9): 1091-1096.
[22] Park Y, Ang A H. Mechanistic seismic damage model for reinforced concrete[J]. Journal of Structural Engineering, 1985, 111(4): 722-739.
[23] Stone, W C, Taylor A W. ISDP: Integrated approach to seismic design of reinforced concrete structures[J]. Journal of Structure Engineering, 1994, 120(12): 3548-3566.
[24] [25]牛荻涛，任利杰．改进的钢筋混凝土结构双参数地震破坏模型[J]．地震工程与工程振动，1996，16(4)：44-54.
NIU Ditao, REN Lijie. A modified seismic damage model with double variables for reinforced concrete structures[J]. Earthquake Engineering and Engineering Vibration, 1996, 16(4): 44-54.
[25] 王东升，冯启民，王国新．考虑低周疲劳寿命的改进Park-Ang地震6损伤模型[J]．土木工程学报，2004，37(11)：41-49.
WANG Dongsheng, FENG Qimin, WANG Guoxin. A modified Park-Ang seismic damage model considering low-cycle fatigue life[J]. China Civil Engineering Journal, 2004, 37(11): 41-49.
[26] 江辉，朱晞．以性能指标为控制变量的强度折减因子[J]．铁道学报，2008，26 (6)：88-95．
JIANG Hui, ZHU Xi. Strength reduction factor model with performance index as control parameter[J]. Journal of the China Railway Society, 2008, 26(6): 88-95.
