Study On Mechanism And Measures For Prevention From Cracking In Sluice Concrete During The Construction Period In Winter

In this paper, the crack problem of concrete structures occurred normally in engineering has been analyzed, the mechanism of cracking was studied and some relevant measurements for preventing the crack have been brought up, the measurements for preventing the crack has been applied in the actual project. The main contents of the present work are as follows:1. A 3-D simulative calculation FEM program concerning temperature field and creep stress field during the construction and operation periods of concrete structures has been developed. By this program, temperature field and stress field of concrete structures of sluice are simulated.2. Combining previous engineering examples, the reasons for cracking of pump concrete sluice structures during construction period of winter were thoroughly analyzed and studied. The reasons of temperature cracks, dry shrinkage cracks are analyzed emphasis.3. The basis principle of improved accelerating genetic algorithm is expatiated, and the temperature parameters of concrete are back analyzed by this method in Jiangtang Lake sluice.4. For the crack mechanism of concrete construct mentioned above, many relevant engineering measures for preventing the cracking are brought up. By using the FEM program, all the measurement was analyzed. Some different results with or without this measurements was compared, the really effect of different measurements were given, which have provided the scientific evidence for the administer of engineering in how to chose the measurement of temperature controlling and crack protecting5. Put the research work into practice. Temperature control and crack prevention of pumping concrete of Jiangtang Lake sluice in Huoqiu county, Anhui province was studied as a case in the paper. The effect of cold wave strike, insulation work, post-pouring belt and pipe cooling on the temperature and stress fields were studied in detail to refrain from cracks on base mat or pier. The application is totally successful and there is no cracking in the project.