环境激励下某轻型木结构校舍动力特性研究
|
摘要
通过对汶川地震后重建的中国第一所轻型木结构校舍进行跟踪测试,获取结构在环境激励下的加速度响应,分析得到结构的模态参数(自振频率、振型、阻尼比)。汶川地震十周年之际,再次进行测试,利用频域分解法对采集的加速度响应进行分析,得到了宿舍楼、教学楼、食堂的前两阶模态,并将结果与九年前该结构刚投入使用时测得的动力特性进行比较。结果表明:三栋单体结构在使用过程中基本自振频率均略有降低,渗水较为严重的宿舍楼自振频率下降最多,下降了15%,且第二阶振型由原横向振动变为扭转;由抗震缝分隔开的教学楼三个区域的振动之间存在较弱的相互影响;此次测试较首次测试增加了测点数量,识别到了更低的模态;实测得到的阻尼比均小于5%。
The objective building was built after Wenchuan earthquake in 2008 and constructed by wood-framed system which was first used for elementary school in China.Several ambient vibration tests have been carried out.Modal parameters such as natural frequency,modal shape and damping ratio are obtained by analyzing the dynamic response.Then results are compared with the ones identified nine years ago when the construction of the structure was finished.It is shown that the fundamental frequency of the dormitory has decreased by 15%,and a little dicrease of natural frequency can also been seen for school building as well as the canteen.The school building is seperated by aseismatic joints into three parts,and from the power spectrum density,a minor interaction with each other can be found.Besides,more modes can be found through increasing the numbers of measurements.Though there is a little discrepency of damping ratio identified,they are all less than 5%.
The objective building was built after Wenchuan earthquake in 2008 and constructed by wood-framed system which was first used for elementary school in China.Several ambient vibration tests have been carried out.Modal parameters such as natural frequency,modal shape and damping ratio are obtained by analyzing the dynamic response.Then results are compared with the ones identified nine years ago when the construction of the structure was finished.It is shown that the fundamental frequency of the dormitory has decreased by 15%,and a little dicrease of natural frequency can also been seen for school building as well as the canteen.The school building is seperated by aseismatic joints into three parts,and from the power spectrum density,a minor interaction with each other can be found.Besides,more modes can be found through increasing the numbers of measurements.Though there is a little discrepency of damping ratio identified,they are all less than 5%.
引文
[1] 中华人民共和国住房和城乡建设部.GB 50005—2017 木结构设计标准[S].北京:中国建筑工业出版社,2017.Ministry of Housing and Ruban-Rural Development of the People’s Republic of China.GB 50005—2017 Standard for design of timber structures[S].Beijing:China Architecture and Building Press,2017.(in Chinese)
[2] 熊海贝,康加华,吕西林.轻型木结构房屋动力特性测试及研究[J].同济大学学报(自然科学版),2011,39(3):346-352.Xiong Haibei,Kang Jiahua,Lü Xilin.Test and investigation on dynamic characteristics of wood-frame constructions[J].Journal of Tongji University (Natural Science Edition),2011,39(3):346-352.(in Chinese)
[3] 中华人民共和国住房和城乡建设部.GB 50011—2010 建筑抗震设计规范[S].北京:中国建筑工业出版社,2010.Ministry of Housing and Ruban-Rural Development of the People’s Republic of China.GB 50011—2010 Code for seismic design of buildings[S].Beijing:China Architecture and Building Press,2010.(in Chinese)
[4] International Conference of Building Officials.Uniform building code[S].Whittier:Carlifornia,1997.
[5] Alberto Cavalli,Daniele Cibecchini,Marco Togni,et al.A review on the mechanical properties of aged wood and salvaged timber[J].Construction and Building Materials,2016,114:681-687.
[6] 张舵,卢芳云.木结构古塔的动力特性分析[J].工程力学,2004,21(1):81-86.Zhang Duo,Lu Fangyun.Dynamic structural characteristics of an ancient timber tower[J].Engineering Mechanics,2004,21(1):81-86.(in Chinese)
[7] 秦术杰,杨娜,胡浩然,等.残损明清古建筑木结构动力特性研究[J].建筑结构学报,2018,39(10):130-137.Qin Shujie,Yang Na,Hu Haoran,et al.Study on dynamic characteristics of a damaged ancient timber structure of Ming-Qing dynasty[J].Journal of Building Structures,2018,39(10):130-137.(in Chinese)
[8] Zhang F L,Ventura C E,Xiong H B,et al.Evaluation of the dynamic characteristics of a super tall building using data from ambient vibration and shake table tests by a Bayesian approach[J].Structural Control & Health Monitoring,2018,25:e2121.
[9] Lam H F,Yang J H,Au S K.Bayesian model updating of a coupled-slab system using field test data utilizing an enhanced Markov chain Monte Carlo simulation algorithm[J].Engineering Structures,2015,102:144-155.
[10] 刘杰,康加华,熊海贝.向峨小学现代木结构校舍动力特性现场实测[J].结构工程师,2010,26(3):130-134.Liu Jie,Kang Jiahua,Xiong Haibei.Field tests on dynamic characteristics of wood-frame constructions in Xiang’e elementary school[J].Structural Engineers,2010,26(3):130-134.(in Chinese)
[11] 何敏娟,周楠楠,孙永良.都江堰向峨小学轻型木结构设计与施工[J].施工技术,2010,39(3):88-92.He Minjuan,Zhou Nannan,Sun Yongliang.Design and construction of a light wood-framed structure in Xiang’e Primary School in Dujiangyan[J].Construction Technology,2010,39(3):88-92.(in Chinese)
[12] (美)Robert E.Coleman,Randall J.Allemang.试验结构动力学[M].刚宪约,杨茂洪,译.北京:清华大学出版社,2012:65-80.Robert E.Coleman,Randall J.Allemang.Experimental structural dynamics[M].Translated by Gang Xianyue,Yang Maohong.Beijing:Tsinghua University Press,2012:65-80.(in Chinese)
[13] 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,2000:23-25.Fu Zhifang,Hua Hongxing.Theory and application of modal analysis[M].Shanghai:Shanghai Jiao Tong University Press,2000:23-25.(in Chinese)
[14] Brincker R,Ventura C,Andersen P.Damping estimation by frequency domain decomposition[C].Proceedings of the 19th International Modal Analysis Conference (IMAC),San Antonio,Texas,Feb.7-10,2000:698-703.
[2] 熊海贝,康加华,吕西林.轻型木结构房屋动力特性测试及研究[J].同济大学学报(自然科学版),2011,39(3):346-352.Xiong Haibei,Kang Jiahua,Lü Xilin.Test and investigation on dynamic characteristics of wood-frame constructions[J].Journal of Tongji University (Natural Science Edition),2011,39(3):346-352.(in Chinese)
[3] 中华人民共和国住房和城乡建设部.GB 50011—2010 建筑抗震设计规范[S].北京:中国建筑工业出版社,2010.Ministry of Housing and Ruban-Rural Development of the People’s Republic of China.GB 50011—2010 Code for seismic design of buildings[S].Beijing:China Architecture and Building Press,2010.(in Chinese)
[4] International Conference of Building Officials.Uniform building code[S].Whittier:Carlifornia,1997.
[5] Alberto Cavalli,Daniele Cibecchini,Marco Togni,et al.A review on the mechanical properties of aged wood and salvaged timber[J].Construction and Building Materials,2016,114:681-687.
[6] 张舵,卢芳云.木结构古塔的动力特性分析[J].工程力学,2004,21(1):81-86.Zhang Duo,Lu Fangyun.Dynamic structural characteristics of an ancient timber tower[J].Engineering Mechanics,2004,21(1):81-86.(in Chinese)
[7] 秦术杰,杨娜,胡浩然,等.残损明清古建筑木结构动力特性研究[J].建筑结构学报,2018,39(10):130-137.Qin Shujie,Yang Na,Hu Haoran,et al.Study on dynamic characteristics of a damaged ancient timber structure of Ming-Qing dynasty[J].Journal of Building Structures,2018,39(10):130-137.(in Chinese)
[8] Zhang F L,Ventura C E,Xiong H B,et al.Evaluation of the dynamic characteristics of a super tall building using data from ambient vibration and shake table tests by a Bayesian approach[J].Structural Control & Health Monitoring,2018,25:e2121.
[9] Lam H F,Yang J H,Au S K.Bayesian model updating of a coupled-slab system using field test data utilizing an enhanced Markov chain Monte Carlo simulation algorithm[J].Engineering Structures,2015,102:144-155.
[10] 刘杰,康加华,熊海贝.向峨小学现代木结构校舍动力特性现场实测[J].结构工程师,2010,26(3):130-134.Liu Jie,Kang Jiahua,Xiong Haibei.Field tests on dynamic characteristics of wood-frame constructions in Xiang’e elementary school[J].Structural Engineers,2010,26(3):130-134.(in Chinese)
[11] 何敏娟,周楠楠,孙永良.都江堰向峨小学轻型木结构设计与施工[J].施工技术,2010,39(3):88-92.He Minjuan,Zhou Nannan,Sun Yongliang.Design and construction of a light wood-framed structure in Xiang’e Primary School in Dujiangyan[J].Construction Technology,2010,39(3):88-92.(in Chinese)
[12] (美)Robert E.Coleman,Randall J.Allemang.试验结构动力学[M].刚宪约,杨茂洪,译.北京:清华大学出版社,2012:65-80.Robert E.Coleman,Randall J.Allemang.Experimental structural dynamics[M].Translated by Gang Xianyue,Yang Maohong.Beijing:Tsinghua University Press,2012:65-80.(in Chinese)
[13] 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,2000:23-25.Fu Zhifang,Hua Hongxing.Theory and application of modal analysis[M].Shanghai:Shanghai Jiao Tong University Press,2000:23-25.(in Chinese)
[14] Brincker R,Ventura C,Andersen P.Damping estimation by frequency domain decomposition[C].Proceedings of the 19th International Modal Analysis Conference (IMAC),San Antonio,Texas,Feb.7-10,2000:698-703.