Taking Yuxian Ancient Stage As An Example To Explore The Influence Of The Size Ratio Of Ancient Buildings On The Seismic Performance

China’s ancient wooden structures possess excellent seismic performance.The size proportion of components in ancient architectural books have their own special regulations.In order to explore whether there is a connection between the special rules on the size proportion of Chinese ancient wooden structures and their seismic performances and why the relationship between the two,two wooden-structural ancient stages in Yu county of Qing dynasty is selected for 3D scanning.The ancient opera stage’s information of material,strength,damage and repair were collected and counted at the same time.The 3D model of ancient opera theater is provided and the size of each component is collected and counted.The size ratio of Yan column(the columns located on the outer axis of the ancient building)and the measure of building width was selected as the research object,the size ratio was changed,and other conditions remained consistent.Models with different size ratios were constructed to compare with their natural vibration performance and energy dissipation capacity under the action of seismic waves to explore the rationality of setting the ratio between the height of eaves column and the width of the Ming face in the Chinese ancient building book Construction Example of Qing Project.The main research results are as follows:(1)The point cloud data collection of LiBaoZi and NanLiuZhuang ancient opera stage was accomplished,the point cloud model of LiBaoZi,NanLiuZhuang and CuiJiaZhai which point cloud data was collected by the same research team was obtained,and the statistical records of the material strength of the ancient buildings and the post-damage repair information were made.(2)The size proportion information of each component of pint-sized wooden structure building in the book of Construction Example of Qing Project have been collected and counted.(3)The feasibility of wooden structure modeling by numerical calculation software of PERFORM-3D was verified.With the increasing of the size ratio on Yan column and the measure of building width,the natural vibration period of the first few modes of the same ancient opera stage model and the development of the energy dissipated by the input of the same seismic energy structure under the same seismiccondition show a state of “stable-suddenly fall-stable-suddenly fall stable”.The first sudden drop is at the 0.5 or 0.6 size ratio,and the second sudden drop was at the 1.0size ratio.For all the models of the two ancient opera stages,the seismic performance of the size ratio of 0.7 to 0.8 is within the second time stable size ratio in the middle.The analysis shows that the smaller scale buildings have better seismic energy dissipating capacity.However,stage’s height is obviously too low and seriously affecting indoor lighting and human activities of the building.The larger size ratio shows that the seismic performance is decreased with the increasing of size ratio.In order to give consideration to both the seismic performance and the practicability of the building,the ancient architectural books stipulated that the size ratio of 0.7 to 0.8of the stable and even seismic performance was the optimal size ratio.The definition of the size proportion reflects the rationality of the ancient construction science and has certain reference significance for the modern architectural design.