| Steel reinforced concrete(SRC) is widely used in constructing transfer storey structure for its high strength, high stiffness, good ductility and good seismic capacity. It is very suitable for large span and large section structures. During SRC construction phase, the formwork support system is the main factor whether the construction can meet the requirements. According to the construction practice of many large engineering projects, the suspended formwork support system is designed and optimized to apply constructing SRC transfer storey structure. The suspended formwork support system is a sort of new construction technology which especially adapts to constructing SRC(steel reinforced concrete) transfer storey structure in high-building, and it can transfer force clearly, construct simply, save a lot of formwork support material, accelerate the construction progress, improve construction efficiency and reduce cost.The construction method of suspended formwork has been applied in practical engineering projects, but the interaction mechanism analysis of the SRC transfer structure and suspended formwork support system lacks of detail theoretical research. Theoretical research significantly lags the engineering application. The construction criterion and technical specification of suspended formwork support system has not been constituted. The theoretical study on decision-making system of formwork support system in constructing SRC transfer storey structure is also not perfect. The applicability of the existing construction methods of formwork support system is also limited.This study focused on the interaction mechanism of SRC transfer storey structure and suspended formwork support system and the decision-making system theory in constructing SRC transfer storey structure. The major completed work is summed up as follow.(1)According to construction practice of SRC transfer storey structure, the study on the structural type characteristics, design models and theoretical calculation methods of formwork support system in construction phase has been summarized, and a new compounding formwork supporting system has been researched and developed.(2) Based on engineering application, the structure of suspended formwork support system for constructing SRC transfer storey structure has been researched, the interaction calculation models of suspended formwork support system and SRC transfer storey structure in construction phase has been built, the mechanical mechanism of suspended formwork system has been analyzed, and the theoretical basis for design decision of suspended formwork system in constructing different type sections’ SRC transfer storey structure has been put up.(3)The calculation theory of normal section bearing capacity of SRC beam has been researched and improved. In the condition that construction effect of suspended formwork system is considered, the theoretical suggesting calculation formula of SRC beam’s ultimate bending moment and yield moment has been put forward. The key parameters such as the steel ratio, rise-span ratio, longitudinal reinforcement ratio, steel position, affecting safety coefficient of SRC transition beam’s normal use has been analyzed.(4) Based on theoretical calculation formula of suspended formwork support system, the numerical simulation analysis has been researched combined with the common data of section and span of SRC transfer structure and the reasonable layout parameters of suspended formwork support system. The key factors affecting security and reliability of suspended formwork support system is determined and the influence law has been summarized.(5) On the basis of engineering practice, the construction technology specification of suspended formwork support system has come into being, and the design elements and layout parameters has been optimized and standardized.(6) According to the characteristics of SRC transition structure, the traditional floor formwork system, suspended formwork support system and compounding formwork support system has been contrasted and analyzed by considering the safety, quality, schedule, technical level, the project cost evaluation, preferably construction method. Combined with principles of theoretical calculation of suspended formwork system, decision-making system for constructing SRC transition structure has been built.(7) In accordance with the decision-making system theory of the SRC transfer structure construction scheme, the suitable design parameters of suspended formwork support system is applied to actual engineering project and provides safe, effective and reliable dates for implementation of the project. It also provides the application guiding ideas and specific method for suspended formwork support system being used to constructing SRC transfer structure on site.(8)The application software for safety calculation of the decision-making system theory of the SRC transfer structure construction scheme is researched and developed. It is provided with friendly visual interface and accurate computing power. It is easy to applying in construction site. |
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