传递函数分析在边坡振动台模型试验的应用探讨
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摘要
传递函数分析对获取振动系统的动力特性参数及估算动力响应具有重要意义。边坡地震模拟振动台模型试验可求算两种传函:反映边坡各点的场地地震动特征的绝对加速度传函(基于测点实测加速度时程)和反映坡体本身振动性质的相对加速度传函(基于测点与坡脚即台面间的实测加速度相对时程)。以弹性体振动方程分析和试验实测,探讨了边坡振动台模型试验中动力特性参数计算的传函选择和以传递函数对动力响应的估算,得出结论:(1)不同于机械模态分析(以绝对传函的模和虚部计算动力特性参数具有等价性),对于边坡模型试验,绝对传函实部和模混入了台面加速度影响,以绝对传函虚部或相对传函虚部才能正确计算动力特性参数;(2)传递函数和台面输入波形Fourier谱的逐频相乘得到动力响应估算谱,与测点实测响应Fourier谱吻合较良好,这种估算方法有助于对不同地震波作用下的边坡动力响应作出总体评价,并指导模型试验中地震波形的合理选取。
Transfer function analysis is an important method for obtaining dynamic characteristics parameters and estimating predictive dynamic response of vibration system.Through earthquake simulation shaking table model test of side slopes,transfer function of absolute acceleration and of relative acceleration could be obtained,which reflected the ground motion and the slope body’s seismic vibration respectively.Based on vibration equation analysis of elastomer and its demonstration model test of a side slope,calculation of dynamic characteristics parameters and predictive estimation of seismic response with transfer function analysis were studied.Two pieces of conclusion have been reached: First,in calculation of dynamic characteristics parameters,using the imaginary part of absolute or relative acceleration transfer function could get more reasonable and accurate result than using amplitude and real part.Second,the predictive Fourier spectra of slope’s seismic response could be estimated by multiplication of transfer function and Fourier spectra of input seismic excitation in frequency domain,and the estimation results was in accordance with model test data.It means that transfer function analysis is not only conducive to investigating slope’s essential response feature under complicated and various seismic motions,but also help to designing the shaking table board’s loading waveform of tests.
Transfer function analysis is an important method for obtaining dynamic characteristics parameters and estimating predictive dynamic response of vibration system.Through earthquake simulation shaking table model test of side slopes,transfer function of absolute acceleration and of relative acceleration could be obtained,which reflected the ground motion and the slope body’s seismic vibration respectively.Based on vibration equation analysis of elastomer and its demonstration model test of a side slope,calculation of dynamic characteristics parameters and predictive estimation of seismic response with transfer function analysis were studied.Two pieces of conclusion have been reached: First,in calculation of dynamic characteristics parameters,using the imaginary part of absolute or relative acceleration transfer function could get more reasonable and accurate result than using amplitude and real part.Second,the predictive Fourier spectra of slope’s seismic response could be estimated by multiplication of transfer function and Fourier spectra of input seismic excitation in frequency domain,and the estimation results was in accordance with model test data.It means that transfer function analysis is not only conducive to investigating slope’s essential response feature under complicated and various seismic motions,but also help to designing the shaking table board’s loading waveform of tests.
引文
[1]李宁,程国栋,谢定义.西部大开发中的岩土力学问题[J].岩土工程学报,2001,23(3):268-272.LI Ning,CHENG Guo-dong,XIE Ding-yi.Geo-mechanics development in civil construction in WesternChina[J].Chinese Journal of Geotechnical Engineering,2001,23(3):268-272.
[2]刘红帅,薄景山,刘德东.岩土边坡地震稳定性分析研究评述[J].地震工程与工程振动,2005,25(1):164-171.LIU Hong-shuai,BO Jing-shan,LIU De-dong.Review onstudy of seismic stability analysis of rock-soil slopes[J].Earthquake Engineering and Engineering Vibration,2005,25(1):164-171.
[3]翟阳,韩国城.边坡对土坝稳定影响的振动台模型试验研究[J].烟台大学学报(自然科学与工程版),1996,(4):67-71.ZHAI Yang,HAN Guo-cheng.Shaking table test oneffect of slope on stability of fill dam[J].Journal ofYantai University(Natural Science and Engineering),1996,(4):67-71.
[4]张平,吴德伦.动荷载下边坡滑动的试验研究[J].重庆建筑大学学报,1997,19(2):80-86.ZHANG Ping,WU De-lun.A shaking-table test researchon rock slope[J].Journal of Chongqing JianzhuUniversity,1997,19(2):80-86.
[5]于玉贞,邓丽军,李荣建.砂土边坡地震动力响应离心模型试验[J].清华大学学报(自然科学版),2007,47(6):789-792.YU Yu-zhen,DENG Li-jun,LI Rong-jian.Centrifugemodel test of the seismic response behavior of a sandslope[J].Journal of Tsinghua University(Science andTechnology),2007,47(6):789-792.
[6]LIN M L,WANG K L.Seismic slope behavior in alarge-scale shaking table model test[J].EngineeringGeology,2006,86:118-133.
[7]凌贤长,郭明珠,王东升,等.液化场地桩基桥梁震害响应大型振动台模型试验研究[J].岩土力学,2006,27(1):7-10,22.LING Xian-chang,GUO Ming-zhu,WANG Dong-sheng,et al.Large-scale shaking table model test of seismicresponse of bridge of pile foundation in ground ofliquefaction[J].Rock and Soil Mechanics,2006,27(1):7-10,22.
[8]武思宇,宋二祥,刘华北,等.刚性桩复合地基抗震性能的振动台试验研究[J].岩土力学,2007,28(1):77-82.WU Si-yu,SONG Er-xiang,LIU Hua-bei,et al.Shakingtable test study on aseismic behavior of rigid pilecomposite foundation[J].Rock and Soil Mechanics,2007,28(1):77-82.
[9]林鹏,卓家寿.岩质高边坡开挖爆破动力特性的传递函数研究[J].河海大学学报,1997,25(6):122-125.
[10]崔江余,杜修力.河谷自由场地震动经验传递函数研究[J].水利学报,2001,(10):58-61.CUI Jiang-yu,DU Xiu-li.Study on empirical transferfunction of gorge freefield ground motion[J].Journal ofHydraulic Engineering,2001,(10):58-61.
[11]傅志方,华宏星.模态分析理论与应用[M].上海:上海交通大学出版社,2000.
[12]顾淦臣.土石坝地震工程[M].南京:河海大学出版社,1989.
[13]王济,胡晓.MATLAB在振动信号处理中的应用[M].北京:中国水利水电出版社,知识产权出版社,2006.
[2]刘红帅,薄景山,刘德东.岩土边坡地震稳定性分析研究评述[J].地震工程与工程振动,2005,25(1):164-171.LIU Hong-shuai,BO Jing-shan,LIU De-dong.Review onstudy of seismic stability analysis of rock-soil slopes[J].Earthquake Engineering and Engineering Vibration,2005,25(1):164-171.
[3]翟阳,韩国城.边坡对土坝稳定影响的振动台模型试验研究[J].烟台大学学报(自然科学与工程版),1996,(4):67-71.ZHAI Yang,HAN Guo-cheng.Shaking table test oneffect of slope on stability of fill dam[J].Journal ofYantai University(Natural Science and Engineering),1996,(4):67-71.
[4]张平,吴德伦.动荷载下边坡滑动的试验研究[J].重庆建筑大学学报,1997,19(2):80-86.ZHANG Ping,WU De-lun.A shaking-table test researchon rock slope[J].Journal of Chongqing JianzhuUniversity,1997,19(2):80-86.
[5]于玉贞,邓丽军,李荣建.砂土边坡地震动力响应离心模型试验[J].清华大学学报(自然科学版),2007,47(6):789-792.YU Yu-zhen,DENG Li-jun,LI Rong-jian.Centrifugemodel test of the seismic response behavior of a sandslope[J].Journal of Tsinghua University(Science andTechnology),2007,47(6):789-792.
[6]LIN M L,WANG K L.Seismic slope behavior in alarge-scale shaking table model test[J].EngineeringGeology,2006,86:118-133.
[7]凌贤长,郭明珠,王东升,等.液化场地桩基桥梁震害响应大型振动台模型试验研究[J].岩土力学,2006,27(1):7-10,22.LING Xian-chang,GUO Ming-zhu,WANG Dong-sheng,et al.Large-scale shaking table model test of seismicresponse of bridge of pile foundation in ground ofliquefaction[J].Rock and Soil Mechanics,2006,27(1):7-10,22.
[8]武思宇,宋二祥,刘华北,等.刚性桩复合地基抗震性能的振动台试验研究[J].岩土力学,2007,28(1):77-82.WU Si-yu,SONG Er-xiang,LIU Hua-bei,et al.Shakingtable test study on aseismic behavior of rigid pilecomposite foundation[J].Rock and Soil Mechanics,2007,28(1):77-82.
[9]林鹏,卓家寿.岩质高边坡开挖爆破动力特性的传递函数研究[J].河海大学学报,1997,25(6):122-125.
[10]崔江余,杜修力.河谷自由场地震动经验传递函数研究[J].水利学报,2001,(10):58-61.CUI Jiang-yu,DU Xiu-li.Study on empirical transferfunction of gorge freefield ground motion[J].Journal ofHydraulic Engineering,2001,(10):58-61.
[11]傅志方,华宏星.模态分析理论与应用[M].上海:上海交通大学出版社,2000.
[12]顾淦臣.土石坝地震工程[M].南京:河海大学出版社,1989.
[13]王济,胡晓.MATLAB在振动信号处理中的应用[M].北京:中国水利水电出版社,知识产权出版社,2006.
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