Study On Seismic Dynamic Response And Seismic Reduction Measures Of Hanpingyangfu Watchtower

HanpingYangfu watchtower in Mianyang is the first batch of key cultural relics protection units in China,more than 1800 years ago,it is one of the most complete in the 45 existing watchtower of the Han Dynasty in China,it has very high value of cultural relics and historical research.Affected by the Wenchuan earthquake,severe damage occurred to the stones in it.In order to prevent further damage to the structure,by means of laboratory test and finite element numerical simulation,mechanical properties of structure before and after repair under earthquake action are studied.The main research results are as follows:(1)The numerical models of Hanpingyangfu watchtower are established by finite element software,seismic dynamic analysis of computational model.the damage mechanics features of dovetail groove and stone are analyzed according to the calculation results.(2)The calculation models of dovetail tenon and non-dovetail tenon in the structure are established and analyzed by finite element software.The results show that: The frequencies of dovetail tenons in the structure are higher than those without dovetail tenons,and the horizontal torsion angle of each layer of stone with dovetail tenon is smaller than that without dovetail tenon.Therefore dovetail tenon can increase the overall stability of the structure.(3)Through uniaxial compression test,water stability test and water resistance test,the optimum mix ratio of filling material is determined as soil: gypsum: lime = 74:12:14(mass ratio).The filling cushion material made by this mix ratio has good compressive strength,water stability and water resistance,and can meet the environment requirements.(4)The repaired structure is calculated by finite element method,and the results are compared with the stress,displacement and acceleration of the structure before repairing.The results show that: After repair,the stress?displacement and horizontal peak acceleration of the structure are reduced.It shows that a proper amount of cushion material filled in the space between the stones can reduce the vibration of the structure.