地震动方向随机性对结构动力反应的影响
|
摘要
实际的地震动在水平面上总是有两个方向,然而,关于双向地震动如何影响结构的动力反应以及只考虑单向作用是否足够,一直都是一个有争议的问题。该文首先分析了分歧存在的原因。在此基础上,主要研究了地震动方向的随机性对结构反应的影响,同时对结构反应的弹性阶段和塑性阶段分别进行分析。结果表明:考虑地震动方向的随机性,在弹性阶段,基底剪力比不考虑该因素时平均增大8%;在塑性阶段,考虑地震动方向的随机性及结构两个方向的受力性能耦合,比只考虑受力性能耦合的情况,地震位移反应平均增大12%,比单向地震作用下的简化2维模型位移反应(既不考虑方向随机性也不考虑受力性能耦合)平均增大15%。最后,通过统计分析,给出了保证95%设计安全性的结构反应增大系数。
This paper investigates structural response characteristics in the consideration of the directional uncertainty of earthquake ground motions.For this purpose,a simple 3-dimensional model is established.In elastic range,Maximum Bilateral Acceleration Response(MBAR),accounting for the variation of imposing directions of earthquakes,is compared with the unilateral one(UAR) based on the analysis of 2-dimensional model subjected to a unilateral earthquake excitation,to evaluate the effect of directional uncertainty in earthquake excitations.In plastic range,Maximum Bilateral Displacement Response(MBDR) is compared with the bilateral one(BDR) and the unilateral one(UDR).The results show that,on average,MBAR is 1.08 times larger than UAR;MBDR is 1.12 times larger than BDR and 1.15 times larger than UDR.At last,a statistical analysis yields magnification factors.Magnifying UAR,UDR and BDR with the corresponding magnification factor will guarantee a probability of 95% design safety.
This paper investigates structural response characteristics in the consideration of the directional uncertainty of earthquake ground motions.For this purpose,a simple 3-dimensional model is established.In elastic range,Maximum Bilateral Acceleration Response(MBAR),accounting for the variation of imposing directions of earthquakes,is compared with the unilateral one(UAR) based on the analysis of 2-dimensional model subjected to a unilateral earthquake excitation,to evaluate the effect of directional uncertainty in earthquake excitations.In plastic range,Maximum Bilateral Displacement Response(MBDR) is compared with the bilateral one(BDR) and the unilateral one(UDR).The results show that,on average,MBAR is 1.08 times larger than UAR;MBDR is 1.12 times larger than BDR and 1.15 times larger than UDR.At last,a statistical analysis yields magnification factors.Magnifying UAR,UDR and BDR with the corresponding magnification factor will guarantee a probability of 95% design safety.
引文
[1]De Stefano M,Faella G,Ramasco R.Inelastic seismic response of one-way plan-asymmetric under bi-dimensional ground motions[J].Earthquake Engineering and Structural Dynamics,1998,27:363―376.
[2]Heredia-Zavoni E,Machicao-Borrniuevo C.Response to orthogonal components of ground motion and assessment of percentage combination rules[J].Earthquake Engineering and Structural Dynamics,1999,33:271―284.
[3]Ghersi A,Rossi P P.Influence of bi-directional ground motions on the inelastic response of one-storey in-plan irregular systems[J].Engineering Structures,2001,23:579―591.
[4]Humar J L,Kumar P.Authors reply to discussion of the paper‘Effect o orthogonal in-plane structural elements on inelastic torsional response’[J].Earthquake Engineering and Structural Dynamics,2000,29:1253―1254.
[5]Lopez O A,Chopra A K,Hernandez J J.Critical response of structures to multi-component earthquake excitation[J].Earthquake Engineering and Structural Dynamics,2000,29:1759―1778.
[6]王东升,李宏男,王国新.双向地震动作用下的拟等延性系数谱[J].地震工程与工程振动,2004,24(4):25―31.Wang Dongsheng,Li Hongnan,Wang Guoxin.Perseudo ductility spectrum under bi-directional earthquake excitation[J].Earthquake Engineering and Engineering Vibration,2004,24(4):25―31.(in Chinese)
[7]ISO/CD 3010,Bases for design of structures–seismic actions on structure[S].1999.
[8]AASHTO,Standard specification for highway bridges,16th Edition[S].1996.
[9]ATC-32,Improved seismic design criteria for california bridges:Provisional recommendations[S].1996.
[10]European committee for standardization(CEN),Eurocode 9[S].1996.
[11]Pacific earthquake engineering research center[DB].http://peer.berkeley.edu
[12]Uniform Building Code.International conference of building officials[S].Whittier,Calif,1997.
[13]Silvia Mazzoni,Frank Mckenna.Open sees command language manual[Z].http://opensees.berkeley.edu.
[2]Heredia-Zavoni E,Machicao-Borrniuevo C.Response to orthogonal components of ground motion and assessment of percentage combination rules[J].Earthquake Engineering and Structural Dynamics,1999,33:271―284.
[3]Ghersi A,Rossi P P.Influence of bi-directional ground motions on the inelastic response of one-storey in-plan irregular systems[J].Engineering Structures,2001,23:579―591.
[4]Humar J L,Kumar P.Authors reply to discussion of the paper‘Effect o orthogonal in-plane structural elements on inelastic torsional response’[J].Earthquake Engineering and Structural Dynamics,2000,29:1253―1254.
[5]Lopez O A,Chopra A K,Hernandez J J.Critical response of structures to multi-component earthquake excitation[J].Earthquake Engineering and Structural Dynamics,2000,29:1759―1778.
[6]王东升,李宏男,王国新.双向地震动作用下的拟等延性系数谱[J].地震工程与工程振动,2004,24(4):25―31.Wang Dongsheng,Li Hongnan,Wang Guoxin.Perseudo ductility spectrum under bi-directional earthquake excitation[J].Earthquake Engineering and Engineering Vibration,2004,24(4):25―31.(in Chinese)
[7]ISO/CD 3010,Bases for design of structures–seismic actions on structure[S].1999.
[8]AASHTO,Standard specification for highway bridges,16th Edition[S].1996.
[9]ATC-32,Improved seismic design criteria for california bridges:Provisional recommendations[S].1996.
[10]European committee for standardization(CEN),Eurocode 9[S].1996.
[11]Pacific earthquake engineering research center[DB].http://peer.berkeley.edu
[12]Uniform Building Code.International conference of building officials[S].Whittier,Calif,1997.
[13]Silvia Mazzoni,Frank Mckenna.Open sees command language manual[Z].http://opensees.berkeley.edu.
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