Analysis Of Detailed Structure Of Large Tonnage Creep Apparatus And Study On Creep Test

Creep is the inherent time-varying characteristics of concrete materials. As for concrete structure, the structural distortion and changes in internal forces caused by creep can not be ignored. Thus, the influence of the creep must be taken into consideration in the process of design and construction.Considering the above-mentioned reason and the need of conducting creep experiment toward relatively-strong concrete for the paper's background project that is the reconstruction project Shudi Bridge in Yunnan after Lining highway inundated by the Jin'anqiao Hydropower Station Reservoir,the paper finally designs and develops the high-tonnage creep apparatus which is able to meet the demand of background project's creep experiment through a large number of visits and researches to different creep apparatuses developed by individual companies. In order to ensure the safe and successful creep experiment carried out under the creep apparatus, the paper hereby conducts the design and analysis respectively for the detailed structure and mechanical characteristic of creep equipment. And the paper focuses on the analysis of two parts of detailed structure of the apparatus. The one is the contact area between creep apparatus spherical hinge and backing plate. The contact stress analysis has always been considered to be a very tedious and complicated process; moreover, this one involves the contact between the curved surface and the spherical surface, which is virtually to complicate the solution process. Considering the complexity of the contact problem, the paper applies the large-scale finite element software ANSYS to conduct structural analysis, the result showing the detailing of the contact area is capable of meeting the need of the actual structure. The other is the compressed spring under the pressure plate. There are four springs in this creep apparatus structure, each of which is to bear the load of 8t. As for the compressed spring, it will be deformed greatly under high load; therefore, the requirement on the structure itself is higher. In order to ascertain the working performance of the compressed spring, the paper also applies ANSYS software to establish models to conduct detailed analysis and researches, through which it is concluded that the spring is able to meet the full demand of the stress requirements of the creep experiment. Therefore, the creep apparatus developed in this paper reaches the intended design target.In the end, the paper carries out creep experiment against the C50 concrete of the superstructure of the background project, studies the long-term deformation rule of concrete materials of Shudi Bridge, figures out the creep curve and shrinkage curve of C50 concrete of the bridge at different ages, and compares the calculation result with the normative result at home and abroad, providing important data for the appropriate control during the bridge construction and operation management in the future.