Technology Research Of Enclosure Structure Reasonable Reinforcement Based On The Improved Temperature Field

Due to the impact of solar radiation, the change of temperature and the smallthermal conductivity of concrete, internal and external temperature difference of boxgirder structure is big which leads to great temperature stress. Existing studies havedemonstrated that sometimes effect caused by temperature difference is greater than thatcaused by the live load and it is also one of the main factors which induces to the boxgirder cracks. Usually, the method used in the project is preloading stress in theconcrete in advance to get larger reserves. This method can resist tensile stress producedby temperature difference inside and outside of the section. It is not only costing a lot ofmoney, but also results in longtime high stress state of concrete structure. It is bad forthe safety and long-term performance. To solve this problem, technical outline usingsolar power socket to reduce the temperature difference inside and outside of box girderis proposed, aims to improve temperature field of box structure to achieve the goal ofincreasing the safety of the structure and optimization of reinforcement amount. Underthe background above, this paper make use of solar energy socket to reduce boxstructure temperature stress thus; the original rebar configuration by consideringtemperature is reduced. The main tasks of this dissertation are as follows:①Through consulting many references of temperature effect and the reinforcementtechnology at home and abroad, learned scholars have carried out extensive research inthe field temperature effect and the reinforcement, but few research on the relationshipbetween temperature effect and reinforcement;②In order to later research on temperature effect and the reinforcement technology,this paper analyzes the temperature distribution of box structure, finds out the basicformula of temperature stress calculation and carry out the research on the calculationmethod of box structure; Systematically introduces the existing concrete structurereinforcement methods, briefly expounds the general steps by using internal force ofreinforcement method, analyzes the widely used method in the hydraulic structure stressof reinforcement, and studies practical strut-and-tie model method in the foreign codesand novelty reinforcement method based on the tensile stress field.③This paper analyzes the temperature effect of long span continuous rigid frame bridge in order to research into the subsequent temperature effect by bridge internalforce and the shrinkage and creep and the amplitude of temperature stress distributionand improves enclosure structure at different temperature gradient (i.e., different degreeof improvement). Thus, detail analysis of box structure is carried out and the detaildistribution is studied. It is concluded that the temperature stress is the surface stress,with the depth of solar radiation, sharply reduced;④On the basis of the research on reinforcement method and the temperature effectof box structure, taking a large span continuous rigid frame bridge in Chongqing as anexample, this paper analyzes the reduction of prestressed structure under the improvedtemperature field and estimate rein for cement amount using the method of normalstress of reinforcement of box structure temperature.