A Study On The Construction Technology For Large Span Preflex Composite Beam In Bridge

Preflex composite beam is one of steel-concrete composite structure form, a new structure on bridge upper structure, it is featured by light beam, convenient operation and light in lifting weight etc. Used especially for flyover, grade-separated interchange in urban and substructure whose depth of beam is limited, we gained the whole benefits. The field is came into late and the application and development of preflex composite beam are restricted to a certain extent due to patent referenced of design and manufacturing process of it. There is no integrated design specifications and technical analysis for it at home and broad so as to not well apply and popularize in our bridge construction.Combined it with my constructional experiences in large span preflex composite beam in bridge, I created a perfect construction technique method on it by making a deep study about economy of preflex composite beam with 40m span bridge, construction method and every stage mechanical properties. I conducted mainly the following works and analyzed economy and unique advantages of preflex composite beam by comparison of economic indicator of single beam, single bridge and multilayer grade-separated interchange. Analyzed construction technology of preflex composite beam, produced construction operational method for double-mutual precompression and did detailed computation analyses on major equipment during construction. Did some mechanical analysis at each construction stage for it and adopted allowable stress method with theory of elasticity so that I gained technical feasibility and modified constructional operations by comparative analysis of construction computed value with in-situ measurements. Its construction technology is feasible, economic benefit is fine and technologic applicability is used widely via further confirmation of bridge loading test, construction equipment will be used many times, data monitoring survey in construction met the requirements, and the appearance of beams are pleasant to eye. So that it will be popularized and applied in coming works. Construction technique was summarized for preflex composite beam in the last part of the theme, and further improvements and researching matters were put forward along with the development of bridge design and construction technique.