Study On Dynamic Performance And Earthquake Damage Mechanism Of Masonry Pagoda

Masonry pagoda is an important constituent of the ancient architecture of China,which combined with foreign and Chinese traditional culture.Because of the large quantity and extremely high cultural value,it is very important to protect our masonry pagodas.At the same time,seismic activity happens frequently in China.Earthquakes will accumulate the masonry pagoda`s damage,resulting in structural damage.So,the seismic damage mechanism of the masonry pagoda is the key to studying the seismic damage of the structure.This paper takes Chongshousi Pagoda in Pucheng County,Shaanxi Provincen as the research object.Introducing the concept of damage evolution to characterize the material properties of the deterioration of the material properties in the structure of the pagoda.So as to analyze the damage characteristics of the structure under the action of earthquake,and carry out the Xingjiao temple's Pagoda's shaking table test.Specific work is as follows:(1)The basic dynamic test of the pagoda are obtained and the dynamic characteristics of the pagoda are calculated by ABAQUS software.According to the test results of the dynamic characteristics,the equivalent calculation parameters and the stiffness damage rate of the floor are determined.The macroscopic damage of the pagoda structure is analyzed.The distribution of the identification results is consistent with the results of the field investigation.(2)A damage evolution model is introduced into the numerical model of the pagoda,which is based on the damage constitutive model of masonry structures.According to the different intensity of the seismic waves inputted,the change rue of the damage parameters of the structure under different fortification intensity were calculated and the damage evolution law of the empty cylinder pagoda were explored.The results show that the damage of the hollow brick structure under earthquake is mainly caused by the accumulation of damage caused by tension.The floor at the bottom and the middle of the structure is a significant area of damage.(3)A 1/8 scale model of Xingjiao Temple's Pagoda was made and a shaking table test was carried out.The experimental data were analyzed and the damage evolution law of the solid structure was studied.The results show that,the damage of this pagoda is also caused by the accumulation of tension damage,The first layer of the structure or the hollow layer is the weak layer,which is the starting region of the structural damage.(4)With reference to the test model,a numerical model is established.For the numerical model,enter the 7-degree EL-Centro wave in different directions.The elastic phase and the elastic-plastic phase of the experiment and numerical simulation are compared respectively.The results show that,in the elastic phase,the displacement,acceleration and basic frequency of the numerical model are in good agreement with the experimental model.In the elastoplastic stage,the macroscopic damage law of the numerical model and the FFT curve of the acceleration curve are in good agreement with the experimental model.Indicating that the numerical model is reliable.