Experimental Study On Shearing Performance Of Assembled Steel Underpinning Replacement Joints Of Round Wood Columns

With the development of modern city construction,the contradiction between development and protection gradually emerged in the process of urban planning and old city transformation.An important building technology-building monolithic moving technology has gradually become a historical building protection,reducing there are important methods such as the demolition and reconstruction of valuable buildings.The modern building overall displacement technology began in the United States in the early 20 th century,and the first use of this technology in China appeared in the 1990 s.In just 30 years,China has hundreds of successful projects..In the process of displacement engineering,underpinning technology is one of its important guarantees,which is related to the stability and safety of the displaced building.For the construction of column load-bearing structures,column underpinning is one of the important factors that affect the success of the displacement project.With the passage of time,more and more ancient buildings will be damaged by various factors such as nature and man-made.The ancient buildings are the testimony of the five thousand years of culture in China.Therefore,the ancient buildings are protected,repaired,or placed Going to a safer place to protect is urgent.Since the ancient buildings are mostly wooden buildings,it is necessary to consider maintaining the original appearance of the ancient buildings during the maintenance process.The traditional repair method will consume a lot of financial resources,and it may not necessarily guarantee that the ancient buildings will not be damaged during the repair process.This article proposes a new type of reusable column underpinning method-round wood column assembled steel underpinning method.In this method,the main materials of the underpinning device are steel and rubber pads.It is a green plate that meets the requirements of environmental protection.The replacement technology can maintain the original appearance of the ancient building while realizing the reliable replacement of the wooden columns.This article focuses on the method of assembling the steel underpinnings of round wooden pillars.Static loading tests are performed on two sets of wooden pillar specimens,one of which is not treated on the surface,and the other is painted on the surface to simulate painted wooden pillars.Each group of columns is subjected to four kinds of preloading forces,respectively measuring the maximum bearing capacity when the column and the undercarriage produce relative slippage and the bearing capacity during slippage.The static friction coefficient is calculated by the maximum test loading analysis of the joint surface,and proposed.The calculation formula of the bearing capacity of the underpinning node is put forward,and the structural design recommendations are put forward in combination with the sliding failure characteristics and the problems found in the experiment.At the same time,the recommendations for future theoretical research are given.The test shows that the steel underpinning device assembled with round wood columns has good bearing capacity and reusability,which can provide a useful reference for practical engineering applications.