考虑地震动摇摆分量作用的输电塔线体系响应
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摘要
为探究输电塔线体系在地震动水平-摇摆耦合作用下的响应,进行了振动台试验和理论分析。地震动摇摆分量通过小波分析的方法从原始地震记录中取得,此方法以单摆式地震仪在水平和竖向的响应差别为基础,通过摇摆倾斜位移的傅里叶谱和竖向速度相似作验证。采用实际输电塔线体系的简化缩尺模型,进行单塔模型和三塔两线模型在顺线向作用下的振动台试验,考察在地震动水平、摇摆及水平-摇摆耦合作用下的结构响应。推导了地震动水平、摇摆加速度和摇摆位移耦合作用下输电塔线体系的动力方程,在方程的激励项中以等效侧向力的形式考虑摇摆转角位移产生的附加P-Δ效应。研究结果表明:理论分析和试验结果吻合较好,证明了理论分析的正确性;地震动摇摆分量不可忽略,其对输电塔线体系的地震响应影响较大,其中由摇摆转角位移产生的附加P-Δ效应会增大输电塔线体系的动力响应,并造成塔体产生一定程度的非对称位移响应;本次试验中,在多维地震作用下,输电线会减弱输电塔主体结构的水平位移和加速度响应,但相对于水平地震动作用,考虑摇摆分量后,输电线对输电塔主体结构响应的减弱效果将会被削弱。
Experimental and theoretical studies of seismic response of the transmission tower-line system under coupled horizontal and tilt (CHT) ground motion were conducted. Based on the different responses caused by the tilt ground motion between the horizontal and vertical pendulum in the single-pendulum seismograph and the similarity relation between the Fourier spectrum of the tilt component and that of the velocity of vertical component of ground motion,wavelet analysis was adopted to obtain the tilt component from the uncorrected horizontal component of ground motion.Taking a real transmission tower-line system as the prototype,the shaking table tests of the scaled model for transmission single tower and transmission three towers-two lines system under horizontal,tilt and CHT ground motions were carried out. Dynamic equations for transmission tower-line system under coupled horizontal and tilt ground motion were derived,in which the additional P-Δ effect caused by the tilt was considered as an equivalent horizontal lateral force and was added into the equations as the excitation. Test results were compared with the theoretical analysis,and the results show that: 1) the results of shaking table tests are consistent with the theoretical analysis adopting the developed dynamic equations,which proves that the theoretical analysis is correct; 2) the tilt component of ground motion has great influence on the seismic response of transmission tower-line system,and the additional P-Δ effect caused by the foundation tilt not only increases the seismic response of transmission tower-line system,but also leads to a remarkable asymmetrical displacement effect,so the tilt component should not be ignored in the practical seismic design; 3) for the transmission tower-line system,the horizontal displacement and acceleration responses of transmission towers are weakened by transmission lines under various ground motions,while the weakening effect of transmission lines on the main structure of system is weakened with consideration of tilt component.
Experimental and theoretical studies of seismic response of the transmission tower-line system under coupled horizontal and tilt (CHT) ground motion were conducted. Based on the different responses caused by the tilt ground motion between the horizontal and vertical pendulum in the single-pendulum seismograph and the similarity relation between the Fourier spectrum of the tilt component and that of the velocity of vertical component of ground motion,wavelet analysis was adopted to obtain the tilt component from the uncorrected horizontal component of ground motion.Taking a real transmission tower-line system as the prototype,the shaking table tests of the scaled model for transmission single tower and transmission three towers-two lines system under horizontal,tilt and CHT ground motions were carried out. Dynamic equations for transmission tower-line system under coupled horizontal and tilt ground motion were derived,in which the additional P-Δ effect caused by the tilt was considered as an equivalent horizontal lateral force and was added into the equations as the excitation. Test results were compared with the theoretical analysis,and the results show that: 1) the results of shaking table tests are consistent with the theoretical analysis adopting the developed dynamic equations,which proves that the theoretical analysis is correct; 2) the tilt component of ground motion has great influence on the seismic response of transmission tower-line system,and the additional P-Δ effect caused by the foundation tilt not only increases the seismic response of transmission tower-line system,but also leads to a remarkable asymmetrical displacement effect,so the tilt component should not be ignored in the practical seismic design; 3) for the transmission tower-line system,the horizontal displacement and acceleration responses of transmission towers are weakened by transmission lines under various ground motions,while the weakening effect of transmission lines on the main structure of system is weakened with consideration of tilt component.
引文
[1]GRAIZER V.Tilts in strong ground motion[J].Bulletin of the Seismological Society of American,2006,96(6):2090-2102.
[2]彭小波,李小军.汶川地震强震动地面倾斜研究[J].地震学报,2012,34(1):64-75.(PENG Xiaobo,LIXiaojun.Study of ground surface tilts from strong motion records of the Wenhuan earthquake[J].Acta Seismologica Sinica,2012,34(1):64-75.(in Chinese))
[3]楼梦麟,杨明珏.地震动摇摆分量对高层建筑结构的影响[J].结构工程师,2014,30(1):86-92.(LOUMenglin,YANG Mingjue.Influence of rocking earthquake ground motion on super high-rise structures[J].Structural Engineers,2014,30(1):86-92.(in Chinese))
[4]李宏男,王前信.水平与摇摆地震动作用下大跨越输电塔体系的反应分析[J].工程力学,1991,8(4):68-79.(LI Hongnan,WANG Qianxin.Response analysis of the system consisting of long span transmission lines and theirsupporting towers to horizontal and rocking seismic motions[J].Engineering Mechanics,1991,8(4):68-79.(in Chinese))
[5]田利,李宏男.输电塔线体系在多维地震激励下的响应分析[J].土木建筑与环境工程,2013,35(1):86-95.(TIAN Li,LI Hongnan.Seismic response analysis of transmission tower-line system under multi component ground motion excitations[J].Journal of Civil,Architectural&Environmental Engineering,2013,35(1):86-95.(in Chinese))
[6]TIAN Li,MA Ruisheng,LI Hongnan,et al.Progressive collapse of power transmission tower-line system under extremely strong earthquake excitations[J].International Journal of Structural Stability and Dynamics,2016,16(7):1550030.
[7]TIAN Li,MA Ruisheng,PAN Haiyang,et al.Progressive collapse analysis of long-span transmission tower-line system under multi-component seismic excitations[J].Advances in Structural Engineering,2017,20(12):1920-1932.
[8]孙建梅,张健,崔浩.多点输入下大跨输电塔线体系抗震稳定性分析[J].世界地震工程,2015,31(4):58-65.(SUN Jianmei,ZHANG Jian,CUI Hao.Research on seismic stability analysis of long-span transmission tower-line system under multiple support excitations[J].World Earthquake Engineering,2015,31(4):58-65.(in Chinese))
[9]李钢,谢强,文嘉意.地震作用下输电塔线耦联体系导线减震作用研究[J].地震工程与工程振动,2015,35(5):47-53.(LI Gang,XIE Qiang,WEN Jiayi.Vibration energy absorption effects of conductors in transmission tower-wire coupling system subjected to earthquake[J].Earthquake Engineering and Engineering Dynamics,2015,35(5):47-53.(in Chinese))
[10]LI Hongnan,SUN Liye,WANG Suyan.Improved approach for obtaining rotational components of seismic motion[J].Nuclear Engineering and Design,2004,232(2):131-137.
[11]CHE Wei,LUO Qifeng.Time-frequency response spectrum of rotational ground motion and its application[J].Earthquake Science,2010,23(1):71-77.
[12]ZEMBATY Z.Tutorial on surface rotations from wave passage effects stochastic spectral approach[J].Bulletin of the Seismological Society of America,2009,99(2):1040-1049.
[13]魏文晖,薛广文,张迪,等.基于小波分析的地震动转动分量研究[J].岩土工程学报,2015,37(7):1241-1248.(WEI Wenhui,XUE Guangwen,ZHANGDi,et al.Rotational components of ground motion based on wavelet analysis[J].Chinese Journal of Geotechnical Engineering,2015,37(7):1241-1248.(in Chinese))
[14]TRIFUNAC M D,TODOROVSKA M I.A note on the useable dynamic range of accelerographs recording translation[J].Soil Dynamics&Earthquake Engineering,2001,21(4):275-286.
[15]梁枢果,朱继华,王力争.大跨越输电塔-线体系动力特性分析[J].地震过程与工程振动,2003,23(6):63-69.(LIANG Shuguo,ZHU Jihua,WANG Lizheng.Analysis of dynamic characters of electrical transmission tower-line system with a big span[J].Earthquake Engineering and Engineering Vibration,2003,23(6):63-69.(in Chinese))
[16]李宏男.结构多维抗震理论[M].北京:科学出版社,2006:328-332.(LI Hongnan.Multi-dimensional seismic theory of structures[M].Beijing:Science Press,2006:328-332.(in Chinese))
[17]魏文晖,甘肃,薛广文,等.考虑地震动摇摆分量作用的高柔结构响应[J].建筑结构学报,2016,37(8):115-122.(WEI Wenhui,GAN Su,XUE Guangwen,et al.Seismic response of highly flexible structure undercoupled horizontal and tilt ground motion[J].Journal of Building Structures,2016,37(8):115-122.(in Chinese))
[2]彭小波,李小军.汶川地震强震动地面倾斜研究[J].地震学报,2012,34(1):64-75.(PENG Xiaobo,LIXiaojun.Study of ground surface tilts from strong motion records of the Wenhuan earthquake[J].Acta Seismologica Sinica,2012,34(1):64-75.(in Chinese))
[3]楼梦麟,杨明珏.地震动摇摆分量对高层建筑结构的影响[J].结构工程师,2014,30(1):86-92.(LOUMenglin,YANG Mingjue.Influence of rocking earthquake ground motion on super high-rise structures[J].Structural Engineers,2014,30(1):86-92.(in Chinese))
[4]李宏男,王前信.水平与摇摆地震动作用下大跨越输电塔体系的反应分析[J].工程力学,1991,8(4):68-79.(LI Hongnan,WANG Qianxin.Response analysis of the system consisting of long span transmission lines and theirsupporting towers to horizontal and rocking seismic motions[J].Engineering Mechanics,1991,8(4):68-79.(in Chinese))
[5]田利,李宏男.输电塔线体系在多维地震激励下的响应分析[J].土木建筑与环境工程,2013,35(1):86-95.(TIAN Li,LI Hongnan.Seismic response analysis of transmission tower-line system under multi component ground motion excitations[J].Journal of Civil,Architectural&Environmental Engineering,2013,35(1):86-95.(in Chinese))
[6]TIAN Li,MA Ruisheng,LI Hongnan,et al.Progressive collapse of power transmission tower-line system under extremely strong earthquake excitations[J].International Journal of Structural Stability and Dynamics,2016,16(7):1550030.
[7]TIAN Li,MA Ruisheng,PAN Haiyang,et al.Progressive collapse analysis of long-span transmission tower-line system under multi-component seismic excitations[J].Advances in Structural Engineering,2017,20(12):1920-1932.
[8]孙建梅,张健,崔浩.多点输入下大跨输电塔线体系抗震稳定性分析[J].世界地震工程,2015,31(4):58-65.(SUN Jianmei,ZHANG Jian,CUI Hao.Research on seismic stability analysis of long-span transmission tower-line system under multiple support excitations[J].World Earthquake Engineering,2015,31(4):58-65.(in Chinese))
[9]李钢,谢强,文嘉意.地震作用下输电塔线耦联体系导线减震作用研究[J].地震工程与工程振动,2015,35(5):47-53.(LI Gang,XIE Qiang,WEN Jiayi.Vibration energy absorption effects of conductors in transmission tower-wire coupling system subjected to earthquake[J].Earthquake Engineering and Engineering Dynamics,2015,35(5):47-53.(in Chinese))
[10]LI Hongnan,SUN Liye,WANG Suyan.Improved approach for obtaining rotational components of seismic motion[J].Nuclear Engineering and Design,2004,232(2):131-137.
[11]CHE Wei,LUO Qifeng.Time-frequency response spectrum of rotational ground motion and its application[J].Earthquake Science,2010,23(1):71-77.
[12]ZEMBATY Z.Tutorial on surface rotations from wave passage effects stochastic spectral approach[J].Bulletin of the Seismological Society of America,2009,99(2):1040-1049.
[13]魏文晖,薛广文,张迪,等.基于小波分析的地震动转动分量研究[J].岩土工程学报,2015,37(7):1241-1248.(WEI Wenhui,XUE Guangwen,ZHANGDi,et al.Rotational components of ground motion based on wavelet analysis[J].Chinese Journal of Geotechnical Engineering,2015,37(7):1241-1248.(in Chinese))
[14]TRIFUNAC M D,TODOROVSKA M I.A note on the useable dynamic range of accelerographs recording translation[J].Soil Dynamics&Earthquake Engineering,2001,21(4):275-286.
[15]梁枢果,朱继华,王力争.大跨越输电塔-线体系动力特性分析[J].地震过程与工程振动,2003,23(6):63-69.(LIANG Shuguo,ZHU Jihua,WANG Lizheng.Analysis of dynamic characters of electrical transmission tower-line system with a big span[J].Earthquake Engineering and Engineering Vibration,2003,23(6):63-69.(in Chinese))
[16]李宏男.结构多维抗震理论[M].北京:科学出版社,2006:328-332.(LI Hongnan.Multi-dimensional seismic theory of structures[M].Beijing:Science Press,2006:328-332.(in Chinese))
[17]魏文晖,甘肃,薛广文,等.考虑地震动摇摆分量作用的高柔结构响应[J].建筑结构学报,2016,37(8):115-122.(WEI Wenhui,GAN Su,XUE Guangwen,et al.Seismic response of highly flexible structure undercoupled horizontal and tilt ground motion[J].Journal of Building Structures,2016,37(8):115-122.(in Chinese))