RESEARCH ON NON-DESTRUCTIVE TESTING TECHNOLOGY IN RENOVATING PROJECTS OF MUKDEN PALACE

With the increasing emphasis on the conservation of cultural relics, the renovation work of historic buildings has become more and more important. Basically, most of the ancient buildings in China are wooden structure. Wood is a flexible material which could resist deformation in the earthquake. The drawback, however, is that they are susceptible to temperature, humidity and other external influences (which will lead to rot, cracks, tilt, foundation settlement, etc.), and poses a hidden danger to entire architecture. Besides, after years of use, the decline in mechanical properties could affects their bearing capacity. Moreover, traditional renovation methods, determining renovation and demolition in the absence of accurate and effective detection and evaluation methods, like eyeballing, knocking, which are simple and depend largely on manual experience and lacks of accuracy, will cause the loss of historical information of ancient construction. Also, Traditional way of stylobate repairing can only be qualitative analysis which are visually or empirically, deciding partial repair or comprehensive replacement. Internal damage remains unclearly and inaccurately that often result in the loss of historical information and over-repair of heritage. Paper aims to interpret with two typical example in Mukden Palace, where located in the temperate sub-humid continental climate, with a huge temperature difference between day and night, one is the stone stylobate of Dazheng Hall, the palace used for holding ceremonies, the other is the wooden structure of Ancestral Temple. Both faced with varying degrees of damage, such as foundation broken, frieze panel inclined and pillar cracked. Non-destructive Testing (NDT) Technology using in those two projects includes 3D scanning, ground penetrating, concrete ultrasonic testing and mineral element analyzing that can collect data more comprehensive than just using traditional methods, especially for internal damage. Then generating the quantitative analysis of damage category. Furthermore, discussing cause of damage and moderately protection methods of the stone stylobate and the wooden structure on the basis of testing. As well as providing references of repairing project of traditional Chinese stony heritage.