地基土特性变化对桩基抗震反应的影响
|
摘要
地震荷载作用下的桩基动力反应在工程设计中越来越受到重视。基于桩-土-结构整体动力有限元法,结合工程实例,建立有限元分析模型,设置粘弹性人工边界,研究水平地震荷载作用下地基土层特性变化对桩基抗震反应的影响。着重探讨了上软下硬和上硬下软两种土层分布情况下,软硬土层相对厚度及弹模比变化对桩基抗震反应的影响。结果显示:桩基和筏基交接处桩顶截面和软硬土层分界处的桩身截面均可能是内力最大截面,桩顶截面和软硬土分界处桩身截面都应是设计需考虑的控制性截面,地基土层特性变化对于桩基弯矩的影响较剪力的影响显著。
The seismic responses of foundation piles have invoked more and more attention in design.With the finite element method of complete dynamic interaction of pile-soil-structure combined with a typical case study in engineering,a finite element analysis model was created with a visco-elastic boundary set at the artificially truncated boundary to study the effects of soil characteristics on seismic responses of foun- dation piles for the case of horizontal seismic loads.In two cases of top soft and bottom hard and of top hard and bottom soft of the soil profile,seismic responses of foundation piles were studied through the variation of relative thickness and the ratio of elastic moduli of the soil layers.The result shows that cross- sections of the pile at the intersection of pile-rafter foundation and at the interface of soft and hard soil lay- ers might be the sections of maximum internal forces so that these sections of the pile should be considered as the control sections in the design of the pile body.Effects of characteristics of the soil profile on the mo- ment of piles are more significant than those on the shear.
The seismic responses of foundation piles have invoked more and more attention in design.With the finite element method of complete dynamic interaction of pile-soil-structure combined with a typical case study in engineering,a finite element analysis model was created with a visco-elastic boundary set at the artificially truncated boundary to study the effects of soil characteristics on seismic responses of foun- dation piles for the case of horizontal seismic loads.In two cases of top soft and bottom hard and of top hard and bottom soft of the soil profile,seismic responses of foundation piles were studied through the variation of relative thickness and the ratio of elastic moduli of the soil layers.The result shows that cross- sections of the pile at the intersection of pile-rafter foundation and at the interface of soft and hard soil lay- ers might be the sections of maximum internal forces so that these sections of the pile should be considered as the control sections in the design of the pile body.Effects of characteristics of the soil profile on the mo- ment of piles are more significant than those on the shear.
引文
[1]肖晓春，迟世春，林皋．地震荷载作用下桩-土相互作用简化计算方法及参数分析[J]．大连理工大学学报，2002，42(6)：719-723．Xiao X C,Chi S C,Lin G.Simplified method and para- metric analysis for pile-soil dynamic interaction under seismic loading [J].Journal of Dalian University of Technology,2002,42(6):719-723.
[2]Kostadinov M V,Towhata I.Assessment of liquefac- tion-inducing peak ground velocity and frequency of horizontal ground shaking at onset of phenomenon [J].Soil Dynamics and Earthquake Engineering, 2002,22(4):309-322.
[3]Zhang C,Wolf J P.Dynamic Soil-Structure Interac- tion [M].Amsterdam,The Netherlands:Elsevier Science B.V.,1998.1-42.
[4]王凤霞，何政，欧进萍．桩-土-结构动力相互作用的线弹性地震反应分析[J]．世界地震工程，2003，19 (2)：58-66．Wang F X,He Z,Ou J P.The elastic seismic re- sponse analysis of pile-soil-structure interaction sys- tem [J].World Earthquake Engineering,2003,19(2): 58-66.
[5]陈波，吕西林，李培振，等．均匀土-桩基-结构相互作用体系的计算分析[J]．地震工程与工程震动，2002，22 (3)：91-99．Chen B,La X L,Li P Z,et al.Computational analy- sis of dynamic homogeneous soil-pile-structure inter- action [J].Earthquake Engineering And Engineering Vibration,2002,22(3):91-99.
[6]李晓莉，王玲玲，马乐为．地基参数以及结构层数对桩-土-结构相互作用的影响[J]．西安建筑科技大学学报(自然科学版)，2004，36(3)：299-302．Li X L,Wang L L,Ma L W.Influence of the founda- tion soil parameters and Structural stories on the pile- soil-structure interaction [J].Xi'an University of Ar- chitecture and Technology(Natural Science Edition), 2004,36(3):299-302.
[7]熊辉，邹银生．群桩(土)—承台—结构的动力相互作用分析[J]．工程力学，2004，21(4)：75-80．Xiong H,Zou Y S.Dynamic interactive anslysis of pile group-soil-structure[J].Engineering Mechanics, 2004,21 (4):75-80.
[8]李培振，吕西林，宋和平．考虑地基土液化影响的高层建筑地震反应分析[J]．地震工程与工程振动，2005，25(2)：141-149．Li P Z,LüX L,Song H P.Effect of subsoil liquefac- tion on earthquake response of highrise building sys- tem [J].Earthquake Engineering and Engineering Vi- bration,2005,25(2):141-149.
[9]Desai C S.Numerical design-analysis fox piles in sands [J].Journal of the Geotechnical Engineer, ASCE,1974,100(GT6):613-6a5.
[10]北京金土木软件技术有限公司，中国建筑标准设计研究院编著．SAP2000中文版使用指南[M]．北京：人民交通出版社，2006，352-387．
[11]杨先健．土—基础相互作用的辐射阻尼[J]．岩土工程学报，2000，22，(4)：416-420．Yang X J.Radiation damping of soil-foundation inter- action systems [J].Chinese Journal of Geotechnical Engineering,2000,22(4):416-420.
[12]王明洋，赵跃堂，钱七虎．用波动有限元法分析土与结构相互作用时设置人工边界的两个问题[J]．岩土工程学报，1995，17(1)：92-95．Wang M Y,Zhao Y T,Qian Q H.Two problems in setting artificial boundary with fluctuation FEM to analyse soil-structure interaction[J].Chinese Journal of Geotechnical Engineering,1995,17 (1):92-95.
[13]Decks A J,Randolph M F.Axisymmetric time-do- main transimtting boundaries[J].Journal of Engineer- ing Mechanics,1994,120(1):25-42.
[14]Shibata A,Sozen M A.Substitute-structure method for seismic design in reinforced concrete[J].Journal of the Structural Division,1976,102(1):1-18.
[15]杨林德，杨超，季倩倩，等．地铁车站的振动台试验与地震响应的计算方法[J]．同济大学学报，2003，31 (10)：1135-1140．Yang L D,Yang C,Ji Q Q,et al.Shaking table test and numerical calculationon subway station structures in soft soil [J].Journal of Tongji University,2003,31 (10):1135-1140.
[2]Kostadinov M V,Towhata I.Assessment of liquefac- tion-inducing peak ground velocity and frequency of horizontal ground shaking at onset of phenomenon [J].Soil Dynamics and Earthquake Engineering, 2002,22(4):309-322.
[3]Zhang C,Wolf J P.Dynamic Soil-Structure Interac- tion [M].Amsterdam,The Netherlands:Elsevier Science B.V.,1998.1-42.
[4]王凤霞，何政，欧进萍．桩-土-结构动力相互作用的线弹性地震反应分析[J]．世界地震工程，2003，19 (2)：58-66．Wang F X,He Z,Ou J P.The elastic seismic re- sponse analysis of pile-soil-structure interaction sys- tem [J].World Earthquake Engineering,2003,19(2): 58-66.
[5]陈波，吕西林，李培振，等．均匀土-桩基-结构相互作用体系的计算分析[J]．地震工程与工程震动，2002，22 (3)：91-99．Chen B,La X L,Li P Z,et al.Computational analy- sis of dynamic homogeneous soil-pile-structure inter- action [J].Earthquake Engineering And Engineering Vibration,2002,22(3):91-99.
[6]李晓莉，王玲玲，马乐为．地基参数以及结构层数对桩-土-结构相互作用的影响[J]．西安建筑科技大学学报(自然科学版)，2004，36(3)：299-302．Li X L,Wang L L,Ma L W.Influence of the founda- tion soil parameters and Structural stories on the pile- soil-structure interaction [J].Xi'an University of Ar- chitecture and Technology(Natural Science Edition), 2004,36(3):299-302.
[7]熊辉，邹银生．群桩(土)—承台—结构的动力相互作用分析[J]．工程力学，2004，21(4)：75-80．Xiong H,Zou Y S.Dynamic interactive anslysis of pile group-soil-structure[J].Engineering Mechanics, 2004,21 (4):75-80.
[8]李培振，吕西林，宋和平．考虑地基土液化影响的高层建筑地震反应分析[J]．地震工程与工程振动，2005，25(2)：141-149．Li P Z,LüX L,Song H P.Effect of subsoil liquefac- tion on earthquake response of highrise building sys- tem [J].Earthquake Engineering and Engineering Vi- bration,2005,25(2):141-149.
[9]Desai C S.Numerical design-analysis fox piles in sands [J].Journal of the Geotechnical Engineer, ASCE,1974,100(GT6):613-6a5.
[10]北京金土木软件技术有限公司，中国建筑标准设计研究院编著．SAP2000中文版使用指南[M]．北京：人民交通出版社，2006，352-387．
[11]杨先健．土—基础相互作用的辐射阻尼[J]．岩土工程学报，2000，22，(4)：416-420．Yang X J.Radiation damping of soil-foundation inter- action systems [J].Chinese Journal of Geotechnical Engineering,2000,22(4):416-420.
[12]王明洋，赵跃堂，钱七虎．用波动有限元法分析土与结构相互作用时设置人工边界的两个问题[J]．岩土工程学报，1995，17(1)：92-95．Wang M Y,Zhao Y T,Qian Q H.Two problems in setting artificial boundary with fluctuation FEM to analyse soil-structure interaction[J].Chinese Journal of Geotechnical Engineering,1995,17 (1):92-95.
[13]Decks A J,Randolph M F.Axisymmetric time-do- main transimtting boundaries[J].Journal of Engineer- ing Mechanics,1994,120(1):25-42.
[14]Shibata A,Sozen M A.Substitute-structure method for seismic design in reinforced concrete[J].Journal of the Structural Division,1976,102(1):1-18.
[15]杨林德，杨超，季倩倩，等．地铁车站的振动台试验与地震响应的计算方法[J]．同济大学学报，2003，31 (10)：1135-1140．Yang L D,Yang C,Ji Q Q,et al.Shaking table test and numerical calculationon subway station structures in soft soil [J].Journal of Tongji University,2003,31 (10):1135-1140.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心