The Vibration Velocity Conversion Research Of Ancient Structure Control Point Under The Action Of Traffic Load

Chinese ancient architecture is an important part of Chinese civilization, which has extremely cultural, historical and artistic value. Without doubt, ancient timber structure who has the most Chinese characteristics and contains a large number of rich historical and cultural information among various structures. However, with the development of transportation infrastructure, urban traffic excitation have a serious impact on the ancient architecture, which is slight, long-term and uncertainty exacerbated by the damage accumulation of ancient timber structure. The security assessment of ancient timber structure was evaluated by horizontal vibration velocity of the top column according to the national standard(GB / T50452-2008).It’s difficult to obtain horizontal vibration velocity of the top column due to various reasons. It’s easy to get one or two layers and other columns of the underlying in the field monitoring. Therefore, this paper focuses on the maximum horizontal vibration velocity conversion between the top and underlying column of ancient timber structure and make security assessment according to specification limits. The paper take Liaocheng Guangyue tower as an object and the main research contents are as follows:Firstly, deduced lateral shape function of ancient timber structure by the principle of minimum potential energy. Then, base on the function to deduce horizontal vibration velocity conversion between the top column and underlying column of ancient timber structure.Secondly, the three-dimensional finite element model of timber structure-high pedestal-annular foundation was established. It’s easy to get horizontal vibration velocity of the top column under traffic excitation by using the implicit dynamics analysis. Base on column velocity amplitude of the first layer, with the wooden structure the horizontal vibration velocity conversion proposed in this paper, Obtain the horizontal vibration velocity amplitude the rest of the top column, Compared with the simulation results of the horizontal vibration velocity amplitude of each layer, The results show that the proposed conversion relation can be applied in practical engineering.Thirdly, the vibration test of dynamic response under traffic excitation for Guangyue tower was conducted. After smooth processing, eliminating tendency and digital filtering, the horizontal vibration velocity of each layer was obtained. Meanwhile, base on column velocity amplitude of the first layer, Guangyue tower remaining layers capitals horizontal vibration velocity amplitude is calculated according to the velocity conversion, which can be verified in the numerical analysis.Fourthly, the astic wave velocity of timber parallel grain was tested by using the non-metallic detector ZBL- U520.Then, the security assessment of Guangyue tower was evaluated by horizontal vibration velocity of the top column according to the national standard(GB / T50452-2008) base on two situations. They are over the permissible value, Guangyue tower is in dangerous state under the current traffic excitation.