Research On Monitoring Method And Key Technology Of Construction Survey For Large Cable Stayed Bridge

With the rapid development of road traffic engineering in China,more and more large bridges are being built.The modern cable-stayed bridge occupies an important position in the modern bridge structure with its good structural performance,spaning ability and beautiful architectural modeling,which has been develop rapidly in the last 50 years.Because of the improvement of the technical level,the span of the cable-stayed bridge is increasing,the structure type is becoming more and more complex,the process is more and more advanced and the construction period is shorter and shorter.Thus,more and more requirements are put forward for the method and efficiency of the cable-stayed bridge monitoring.However the efficiency of the traditional cable-stayed bridge measurement and monitoring method is low and the accuracy is not stable enough,which could not able to be applied to the rapidly developing modern society.In view of this situation,the main research contents of this paper include the following points:First,the method and technology of the repetition measurement and densification used in the process of 3d construction control network are introduced,and the related technical details of using intelligent total station for cross river elevation measurement are studied.Its accuracy and method are also analyzed in the paper.Second,the precision positioning method of the key structures on the high tower columns,such as the cableway tube and the steel anchor beam,is introduced in the construction monitoring process of the cable-stayed bridge.The new technology of elevation and plane positioning of the cableway tube and steel anchor beam using the indirect height difference transfer method and the free station method is proposed.And the accuracy and technical advantages of the two methods are analyzed by using the differences between the two sides of constructor and monitoring party.Third,this paper introduces the layout of the measurement and control points of the cable-stayed bridge and the control method of the height and middle line of the beam section.The cycle process of "measurement-adjustment-measurement" for the construction survey and monitoring of the cable-stayed bridge is analyzed,and a high efficiency control scheme of the main beam suspension is designed.The prediction model is established by using multiple linear regression analysis and the spatial position data information of the control points before and after the assembly of the beam section,and then the working time and workload of the measurement and monitoring are reduced,and the purpose of higher efficiency is achieved.To sum up,this paper makes a comprehensive research and application experiment on the key technology of the measurement and control of the cableway pipe,steel anchor beam and the main beam section during the construction process of the large cable-stayed bridge,and puts forward the accurate positioning method of the horizontal and vertical location of the above structures,respectively,by using the total station free station method and the indirect height difference transfer method.It has been applied in the construction of a large cable-stayed bridge,and achieved good results in monitoring and control.