| Chinese ancient buildings hold rich historical, cultural and social backgrounds. The cultural heritage of ancient buildings is a non renewable asset that is of utmost significance to the people of China. The protection of these buildings with structurally strengthened ancient techniques is not an easy task, for the aesthetics of the building being held in high esteem, should be preserved in the process. The Tianshui Houjie Mosque is used as the point of reference for this research, based on the concept of ancient architectural brick structural features. The finite element and numerical simulation analysis are carried out on the structural model before and after the Houjie Mosque is advanced in base isolation, while analyzing the structural seismic characteristic performances.In this thesis, the description of the failure characteristics of ancient buildings under earthquake actions is first discussed, combining the relevant literature of reinforced masonry structures on these ancient buildings, with those of the traditional structures and then summarizing their principles of usage. On the basis of this, the thesis puts forward the idea of strengthening these ancient buildings, thus improving their seismic performance with the use of the seismic isolation technology, and also introducing the working principles behind the isolation device. The vertical and horizontal properties of laminated rubber bearings are then studied.Secondly, the thesis adopts a combination of structural characteristics and coordinative functional properties of the ancient buildings of brick and wood structure. The development of the entire finite element analysis model is simplified and comparative analysis made between the isolated and the non-isolated structural models, analyzing their effects for before and after strengthening the structural model, while incorporating the different earthquakes in the conduction of the time history analysis. The damping effect of seismic isolation and strengthening of the building is thus analyzed and compared. In the modal analysis,the isolated and non- isolated models of the Houjie mosque with ten modes and their vibration cycles are analyzed, by studying the quality of the first three order modes, the characteristic vibrations of the first three order modes of the isolated and then the non isolated structural models. In conducting the time history analysis, the inter-story shear forces of the seismic ground motions in the seismic isolated and non isolated models are obtained, and then the acceleration curves of the two models are derived. It is found out that the acceleration time history response curves and the input seismic time history curves are consistent with the trend and the expected peak values from the codes of practice. Furthermore with the time history analysis, the frequent earthquakes in the Y direction for the base of the wall in the different seismic time history curves of the shear response curves are analyzed. The horizontal shear forces are analyzed for the displacements in the X and Y directions for the isolation layer of the different seismic ground motions under the rare earthquake action.Finally, the simplified calculation method of seismic isolation structure, which is different from the《code of seismic design of building》, 《Technical specification for isolation of laminated rubber bearings》and 《Description of performance-based seismic design of buildings and general provisions》is carried out by analyzing and comparing the seismic isolation effects for before and after the base isolation, the calculation results of the three different methods are then analyzed and compared. It is found that the calculated results of the first two kinds are almost the same, but the difference in deviation of the third calculation results is great. With respect to the analysis results, it shows that the calculation results obtained using the simplified method proposed by the《code of seismic design of building》has a relatively minimum error. |
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