Research On The Design And Application Of New Type Independent Tower's Cable-hoisting System

Non-support cable hoisting is a frequently-used construction method of bridge construction. Up to now it has witnessed countless bridges built after being produced. Therefore, it has an important position in the bridge construction history. However, the study of hoisting system tower, traditionally, mostly focuses on gate-type tower. But research on independent-type tower cable hoisting system is rarely reported. Thus, to strengthen the research on them has important practical significance.The thesis conducts a study to the design of a new and independent tower cable lifting system. Carrying out the feasibility demonstration combined with the bridge example. Through the theoretical calculation and analysis of the test results in construction monitoring, and then the effect of implementation on this system's general application is summarized. The research work which has done can provide the reference for popularization and application of the tower. The specific contents are as follows:(1) To summarize traditional gate-type tower and independent-type tower's application status of bridge cable hoisting, and the research stadus of construction monitoring. Pointing out the existing problems among cable hoisting tower, lifting system and construction process monitoring, and then determining the research contents of the thesis. On this basis, the concept design of new independent-type tower's cable lifting system is put forward. Thereinto, the tower section's illustration is mainly on the split joint fashions (selection of different connecting members) and realization way of the integral traversing, etc. The cable hoisting system section is discussed mainly on the aspects of principle of operation, construction essentials, etc. After that, the advantages of the tower are summed up and analyzed from such as safety, economy, construction convenience aspects, etc.(2) The thesis takes Pingkeng Bridge in Shouning County of Ningde City as the engineering background. Through the field investigation, reasonable bridge lifting scheme that uses cable lifting system of the new independent-type tower is determined by mastery and analysis of the bridge's special geological conditions and surrounding environment, suiting their measures to local conditions. Then the work that carrying out the cable selection and calculation of the whole bridge cable hoisting system, using the finite element analysis software to analyze the stress of tower structure, design and calculation of tower sidesway, checking the anchoring system of East and West cross-strait is done. It turns out that the full bridge has high design integrity and the calculation results of them can meet the design requirements.(3) The construction camber distribution curve of the main arch rib is drawn by using bridge analysis software Midas to simulate process monitoring in the different construction stages such as hoisting and closing of arch rib's arch box segment, bridge deck pavement completed, creep of 10 years later, etc. The theoretical calculation results can provide the references for the main arch construction control and ensuring the alignment of the arch bridge.(4) Through staying in the scene of Pingkeng Bridge for actual measurement, the work which has been done includes two aspects, one hand is about monitoring and measurement of arch rib's elevation and axis; the other hand is about strain test of the main arch ring's sections(such as soffit,skewback,vault, and so on). Data shows that, elevation and axis deviations of the arch boxes'closure can meet the assessment requirements, and internal stress distribution in the arch boxes is reasonable, in summary, the overall trend is consistent with the design expectations. Further, it is validated that the whole work inside the new independent-type tower cable lifting system is feasible and effective.