An Alignment And Attitude Control System For Precast Construction Of Segmental Concrete Bridges

Because of many advantages, precast-assemble method is becoming more and more popular in the construction arena of segmental concrete bridges. However, lacking of an efficient control method for alignment and attitude during casting period, this kind of construction is districted, especially when the segments are casted by short-line casting method.The dissertation is objected to establish a method to control the alignment and attitude of segmental concrete bridges when the segments are casted. With the research on the process and procedure of segment casting and measurement of controlling geometric variables, the types and influence of the casting deviations are found and three kinds of correction methods are concluded, which are direct modification method, angle optimized method and linear modification method. At last, an alignment and attitude control method is formed.Based on this theoretical research, a corresponding control system is developed on the platform VC.NET 2005, which uses the ADO object to manipulate databases and the open graphic interface OpenGL to realize the image technology. Finally, a calculation model of a real bridge project is built in the system. Through a series of testing of the system, it is found that the control theory is correct and well realized by computer technologies.