Study On The Hydration Heat Effect Of Ganlong The Three Railway Lines Mei River Super Large Bridge Pier’s Concrete

Due to the high rate of hydration heat and the bad performance of heat transferring of the concrete, there exit a wide range of temperature difference inside and outside the concrete as well as an internal constraint. Furthermore, the contraction happening in layered pouring leads to the external constraint. All of the above factors result in the cracks, which are normal but attached high importance in the project. Taking the Mei River Super Large Bridge as the project background, this thesis combines it with project construction demand and adopts the large finite element software to carry out a simulating analysis in order to explore the hydration heat effect of massive concrete structures and find out anti-cracking measures. The following are the main contents of this thesis:1. Based on the summary of the meaning of controlling temperature cracks in massive concrete structures, national and international research status and temperature calculation theory and method, this thesis introduces the thermodynamic parameters’characteristics and value and analyzes the reasons for the temperature crack in massive concrete structures.2. This thesis sets up a three-dimensional limited model for the background project with the aid of solid70element stimulating concrete and fluid116element stimulating cooling pipe. This model can carry out a stimulation analysis on pier of Mei River Super Large Bridge and conclude the distributing and changing patterns of both temperature field and stress field of massive concrete structures. Through a comparative analysis on the model data with the measured data, the research ensures the reliability and accuracy of the model as well as the inevitability of the cracks in the background structures.3. The thesis develops a numerical analysis on the common used temperature control measures in project. The numerical analysis in this thesis includes the effect and influence range of cooling pipe, the stage pouring thickness of the concrete and the sensitive parameter of the cooling pipe like the flowing speed, water temperature in inlet and the width between pipes. Some useful conclusions are drawn through numerical analysis.4. Combined the above analysis with the national and international project practice, the thesis put forward some practical measures for controlling temperature crack which include the block pouring of the concrete, the spacing width of cooling pipes, the temperature controlling of the inlet of the cooling pipe and the strengthen of the construction management.