Study On Construction And Control Technology Of Stay Cables

As major force components of cable-stayed bridge, stay cables withstand almost all dead load and live load. Thus, tension in the cables and the construction process must be accurately measured in order to ensure the structural safety and construction control works smoothly.This thesis studies the construction techniques of cables and the control methods of cable forces in cable-stayed structure. The main works carried out are as follows:(1) The history including development of cable stays are introduced, and the important role of force control in the cable-stayed construction is discussed.(2) The structural types and the corresponding construction methods, which commonly used for cable-stayed bridge domestically, are analysed. Through the research for two main cable-stayed structures most commonly used, actual construction process in different projects is discussed.(3) By the analyzing of applying cable force for two kinds of cable-stayed structures, the best construction technology in force control under different conditions is discussed.(4) For the measurement and test of cable force, the thesis analyses the pressure gauge method, the compressive stress method, vibration frequency method and the basic principles of magnetic flux method, respectively. The force sensor in the detection of cable force is described as well. And comparative analysis of measurement methods of cable force and the advantages and disadvantages is made. As a new method, the magnetic flux method obtained good effect in detection of cable force, which may be used as a long-term means.(5) Through some case studies the issues encountered in practical engineering are explored by integrating theory with practice, and corresponding solutions are suggested.