Research On The Seismic Performance Of Bracket Sets Used In Ancient Timber Structure Of Qing-style

Chinese ancient timber structure is a highly "organic" architecture, multi-layered structure can dissipate seismic energy, reducing structural response under earthquake, especially the unique structure of Corbel bracket set; For thousands of years, ancient timber structures do not change their basic characteristics, become the independent system of eastern architecture.Taking the embrasure watchtower of Yongning Gate of Xi’an city wall reconstruction project as the background, through consulting literature, historical photos and refer to other gates watchtower layout and dimension, determine the general shapes of the embrasure watchtower of Yongning Gate, bracket types and the level of bucket; According to "Qing structure regulations" in bracket practice, producing the scale model of three single bracket set and two structure layer with bracket sets, conduct research on the seismic performance of model test and theoretical analysis. Mainly to complete the following tasks:(1) briefly describe the historical overview and current status of embrasure watchtower of Yongning Gate, and study on design theory and design basis, through field survey, literature and reference to other embrasure watchtower’ shape and dimension, determine the embrasure watchtower of Yongning Gate and the level of bucket, as well as the design concept of "repair it as old"; Systematically introduce the bracket sets of origin, evolution, type, and function.(2) Physical and mechanical properties of wood is complex, by introducing orthogonal symmetry principle, it is simplified to orthotropic material, consult the book "wood structure design manual" gives elastic modulus and shear modulus, as well as some mechanical strength values of Pinus armandi; compared with new wood and old wood by experimental method, found that the physical and mechanical properties of wood does exist bigger difference as wood aging.(3) The bracket set models are carried out by pseudo static test, study the displacement ductility, stiffness degradation rule, strength degradation rule, coordination, equivalent viscous damping, the cumulative hysteretic energy, the results show that ancient timber structures with good energy dissipation capacity; Combine with bracket set model under loading condition experiment phenomenon and structure failure characteristics, the bracket set under load working condition is divided into three stages:elastic stage, elastic-plastic stage, destroy stage, and qualitative description in different stages of the load transfer path, the energy consumption and easy to damage; The bracket set model is simplified to single degree freedom system (SDOF system), with the vibration transmission rate (TR) for quantitative analysis of its ability to reduce isolation; Finally, combined with practical engineering, some maintenance measures are given to the bucket, arch and plate fang...