Study On Restoration Plan Of Yingxian Wooden Tower

Yingxian Wooden Tower,built during the Song and Liao dynasties in today's Shuozhou city Shanxi Province,is the largest ancient building in China.The wooden tower experienced wind and rain for nearly a thousand years,and was hit by shells in modern times,which caused damage to some components,seriously incline of 2nd apparent floor and continuous development of laterotorsion.Since the 21st century,different experts and scholars have put forward some maintenance methods,such as deconstructing and repairing overhaul,full support,lifting the upper part etc.However,some problems that are difficult to be solved still exist from the aspects of project quantity scale,damage of the tower during restoration and protection of immovable cultural relic inside the tower.In this paper,based on many years of research and accumulation in the research group and in line with the principle of "not changing the original appearance of cultural relics",some applicable engineering technology are selected and a set of restoration project are put forward,according to the idea of“supporting beam and changing column","replacing damaged components in situ" and "correcting displaced member".According to the characteristics that Chinese traditional wood structures are composed of wood members laid horizontally and connected by mortise and tenon,the basic idea of restoration is to take the damaged members out of the original structure through proper supports,repair or replace them and put them back in the original position.The supporting structure is a special external auxiliary building with functions in different aspects.Inside,it is equipped with special facilities such as conveyor passage,crane,air conditioner,temporary cultural relic storage room,repair workshop,monitoring and security room,special observation platform for sightseeing,etc.This structure serves as a counterforce supporting 24 sliding truss cantilevers on eight sides,penetrating into the third apparent floor.Soft protective pads are used to separate the truss from the wooden members to avoid new damage caused by local extrusion.This plan makes every effort not to damage the wooden structure and internal immovable cultural relics during the restoration process.The auxiliary building is able to be dismantled after the completion of repair,including temporary foundation and all the newly added structures.The superstructure is designed as assembly type,which can be disassembled and assembled without damage.The site meet the special requirements of no sparks,no oil,no dust,no vibration,low noise,etc.Auxiliary building structure design is the main content of this paper.The structure type,column grid,story height,numbers of layer,size of cantilever,foundtion type,ground protection scheme and special technology of no welding steel frame structure at construction site are all designed according to the situation in site,size and material properties of the actual tower and protecting principles of heritage-'no damage' and 'recoverable'.The auxiliary building use the most conventional and safest structure form and construction method to avoid all kinds of possible uncontrollable factors from many aspects,so as to ensure no damage to the wooden tower.The building has reliable safety performance under the working load.The research results are a set of structural construction design drawings of the auxiliary building,which are drawn according to the depth requirements of construction drawings.