Analysis To Aseismic Performance And Research Protections Of Jiayuguan Pass Tower

Ancient Chinese buildings is not only a precious heritage of our great country, it’salso the crystallization of the wisdom of the ages of the working people, and it hasimportant scientific value that deserved we are learn. The Jiayuguan pass tower wasselected as a research object in this article, the purpose was designed to reveal theoverall aseismic performance of the Qing Dynasty Multi-storey timber structure, and itwas provided the reliable theoretical foundation of protection, maintenance andreinforcement, as well as the technical reference for its protection. It also gave us thesignificant enlightenment to the aseismic research and design of the modern structure.Firstly, the structural features of the traditional Qing Dynasty timber structure wassummarized in the paper,. The aseismic mechanism and the mechanics characteristicwas studied and analyzed to this structural by the related literature. The results wereindicated that the ancient Chinese timber structure has the better aseismic capacity thanother structure, which were incarnated on the vibration isolation of the float connectionbetween column foot and plinth, the mortise-tenon joints of beam-column by frictionenergy dissipation, and the tou-kung layers by the vibration isolation and damping.Secondly, combined with the structural characteristics and mechanics characteristics ofthe timber structure and by reasonable simplifying, the overall structure finite elementmodel was established by SAP2000finite element analysis software. Based on thebearing capacity of the component model analysis and structure dynamic analysis, theleading contents have been done as follows:The bearing capacity of the structure was analysised by code for structure designof buildings, the result shows that the carrying capacity of structural member meet thedesign requirements, structure is safe within the seismic intensity,and the material strength also has a very big margin.The margin of column members was about70%,beam member was about50%.Through the modal analysis to the model, all orde modal period and frequencywas obtained, and also through the mass participation factor analysis, the vibrationcharacteristics of each vibration mode was obtained.By comparing the period of the structure between float connection and rigidconnection, the results indicated that the float connection mode between the columnand plinth can lengthen structure’s period approximately47%to57%. According to theenergy balance theory, horizontal seismic action was reduced by lengtheningstructure’s period, and the results show that float connection had a certain degree ofisolation damping effect.Through the response spectrum analysis to the timber structure model, thedynamic magnification factor of column foot and overall structure was obtained, thedynamic magnification factor respectively was0.859and0.614.By the power time interval analysis to the timber structure model. The dynamicmagnification factor of each layer was obtained. By comparing structure characteristicbetween ta-mu-tso and x-mu-tso, the results indicated that they have common vibrationisolation of the float connection and friction energy dissipation of mortise-tenon jointsof beam-column, the difference was that the tou-kung on eaves column don’t haveaseismic ability but only decorative function. The dynamic magnification factor wascontrasted on same layer in different seismic excitation, the results were found littlechange, this shows that the overall aseismic performance of x-mu-tso was not precedeto ta-mu-tso, and was not obvious on intelligent shock absorption.By the energy analysis to Qing Dynasty Multi-storey small timber structure model,the results were indicated that friction energy dissipation were incarnated on themortise-tenon joints of beam-column, which accounted for about71.2%. The vibrationisolation of the float connection between column foot and plinth was smaller thanmortise-tenon joints of beam-column, which accounted for only3.2%.Finally, this paper introduces the basic principle of maintenance andreinforcement in Chinese cultural relics. Combined with the Japanese advanced theprotection of cultural relics, several improvements proposal about maintenance and reinforcement was put forward.