Active Control Of Verticality Of Thin-wall High Pier Based On Measured Temperature Field

Prestressed concrete continuous rigid frame bridge is widely used in highway of mountains because of its characteristics of smooth running and large span capacity.This kind of bridge is mostly located in the valley,the pier is often more than one hundred meters.For the concrete pier near to 100 meters,the verticality of high pier will be affected by the sunshine temperature load in the process of construction,which will affect the stability of high pier in construction process.This article studies on the internal temperature field of thin-walled high pier based on the construction control project of Liang Shui bridge,and puts forward the method of high pier verticality control considering the effect of temperature load.According to the theory of the temperature field of concrete,this article describes four assumptions for the hollow thin-walled high pier temperature field research,and analyzes the factors affecting the distribution of temperature field of pier.At the same time,several methods for solving the sunshine temperature field of high pier are introduced.Through the comparison and analysis,the semi empirical and semi theoretical method is adopted to solve the sunshine temperature distribution formula of thin-walled hollow high pier.Futher more,the regulation of the temperature gradient of thin-walled hollow high pier structures in china and abroad bridge norm is summarized.Based on the study of temperature field theory of thin-walled high pier,several representative weather conditions are chosen to measure the temperature field of thin-wall hollow high pier of Liang Shui bridge.According to the measured temperature datas,this article analyzes the rules of temperature field of hollow thin-walled high pier.At the same time,according to the measured temperature field datas,the least square method is used to solve the temperature distribution formula of the high pier along the side of the Bai Shan side.Finally,this article analyzes the influence of verticality of high pier under the sunshine temperature load,and an active control method of verticality of thin-walled hollow high pier based on measured temperature field is proposed.The principle and construction control flow of active control method of high pier verticality are describled in detail,and this method is used to the construction monitoring project of high pier of Liang Shui bridge.The monitoring data from the actual construction shows that the method reachs the requirements of construction accuracy,and avoids the disadvantages of the traditional methods.It can be extended to other high pier construction monitoring projects.