多维爆破地震动作用下框架结构动态响应有限元时程分析
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摘要
爆破震动的幅值、频率与持续时间是影响结构爆破震动响应与破坏的重要参数,爆破安全规程规定地面建筑物的爆破震动判据采用质点峰值震动速度和主震频率,但没有指明是三向速度的合速度还是单向速度,给爆破震动判据应用带来不便。采用有限元时程分析讨论了不同爆破震动频率速度荷载作用下结构的动态响应,指出在较高频率的爆破震动荷载作用下,框架结构对竖直向地震波响应较大,易在竖直向地震波作用下产生破坏,并可以将三维爆破震动中最大震动速度幅值作为爆破震动安全标准值;在较低频率的爆破地震荷载作用下,震动的水平荷载引起结构的破坏是主要的,应考虑水平最大荷载的爆破震动安全标准值。即结构抗震的安全标准在高频时以垂直荷载速度峰值为准;在低频时以水平荷载速度峰值为准。
Safety regulations of blasting stipulates that the criteria of structural blasting vibration are the peak vibration speed of mass point and the main vibration frequency,but it doesn't point out whether the speed is total speed of three directions or one direction speed,which makes trouble to apply the blasting vibration criterion.In the paper,the structural dynamic responses under different blasting vibration frequency-speed-loads were discussed by use of the finite-element time-history analysis,and it is pointed out that under higher frequency blasting loads,the frame-structural response due to vertical blasting vibration is greater,which means the structure will get broken much more easily under vertical blasting vibration.So,the maximum speed amplitude among the three-dimensional components of blasting vibration can be used as the safety standard of blasting vibration.Under blasting vibration loads of lower frequency,structural damage caused by horizontal blasting load is the primary.So,the maximum horizontal load should be used as the blasting vibration safety standard.Namely,the vertical speed amplitude under high-frequency loads or the horizontal speed amplitude under low-frequency loads can be used as vibration-resistant safety standard.
Safety regulations of blasting stipulates that the criteria of structural blasting vibration are the peak vibration speed of mass point and the main vibration frequency,but it doesn't point out whether the speed is total speed of three directions or one direction speed,which makes trouble to apply the blasting vibration criterion.In the paper,the structural dynamic responses under different blasting vibration frequency-speed-loads were discussed by use of the finite-element time-history analysis,and it is pointed out that under higher frequency blasting loads,the frame-structural response due to vertical blasting vibration is greater,which means the structure will get broken much more easily under vertical blasting vibration.So,the maximum speed amplitude among the three-dimensional components of blasting vibration can be used as the safety standard of blasting vibration.Under blasting vibration loads of lower frequency,structural damage caused by horizontal blasting load is the primary.So,the maximum horizontal load should be used as the blasting vibration safety standard.Namely,the vertical speed amplitude under high-frequency loads or the horizontal speed amplitude under low-frequency loads can be used as vibration-resistant safety standard.
引文
[1]易方民,高小旺,张维嶽.高层建筑钢结构在多维地震动输入作用下的反应[J].建筑结构学报,2003,24(3):33-43.
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[3]刘伯权,等:建筑结构抗震设计[M].北京:中国建材工业出版社,1996,52-61.
[4]薛素铎,等:结构多维地震作用研究综述及展望(Ⅱ)——分析方法及展望[J].世界地震工程,2002,18(1):34-40.
[5]李宏男.结构多维抗震理论与设计方法[M].北京:科学出版社,1998,148-174.
[6]LS-DYNA.User’s Manual:Nonlinear Dynamic Analysis of Structures in Three Dimensions[M].Livermore CA:Liver-more Software Technology Corporation,1997.
[7]陈士海.爆破地震动作用下结构破坏安全标准研究[D].南京:解放军理工大学,2004.
[2]任胜谦,等:高层建筑不规则结构多维地震效应组合研究[J].建筑科学,2003,19(4):9-13.
[3]刘伯权,等:建筑结构抗震设计[M].北京:中国建材工业出版社,1996,52-61.
[4]薛素铎,等:结构多维地震作用研究综述及展望(Ⅱ)——分析方法及展望[J].世界地震工程,2002,18(1):34-40.
[5]李宏男.结构多维抗震理论与设计方法[M].北京:科学出版社,1998,148-174.
[6]LS-DYNA.User’s Manual:Nonlinear Dynamic Analysis of Structures in Three Dimensions[M].Livermore CA:Liver-more Software Technology Corporation,1997.
[7]陈士海.爆破地震动作用下结构破坏安全标准研究[D].南京:解放军理工大学,2004.