Thermal Stress Simulation Analysis During Construction Period And Temperature Control Measures For Crack Prevention Studies On RCC Gravity Dam

Thermal stress is one of'the main stresses of RCC (Roller Compacted Concrete) gravity dam during construction period, so simulation analysis on it is a very important research subject. In this paper, based on the construction characteristics such as thin-layer placement and continuous construction of RCC gravity dam, ANSYS software, a world wide popular common software used in finite-element analysis, is suggested to simulating the temperature field and stress field of RCC gravity dam during construction period. By congregating some advanced functions of ANSYS, the procedure of simulation is provided, in which, the change of atmosphere temperature and concrete hydration heat changing with the age and the initial temperature of concrete as well as the real effect of placing in layers are all taken into account. This method not only has less errors and more precise results, but also shows the results directly and makes the operation more simply, so technicians of any level can use it. This will have some practical values.Longtan RCC gravity dam is the highest RCC dam in construction of the world at present. In this paper, the temperature field of the 11th section of longtan RCC gravity dam during construction period is given by use of ANSYS software. The results of analysis indicate that the ambient temperature and construction velocity has grate effect on the maximum temperature in the RCC gravity dam, but the foundation size and the stress field has less effect. So more attention should be put on the different stress distributing of the points at the different part in the dam.Based on the characteristics such as modulus of elasticity and unit creep changing according to concrete age, the procedure of simulation on thermal stress of RCC gravity dam during construction period is provided by use of ANSYS software. Finally, according to the information in the field of temperature control and crack of some RCC dams domestic and foreign, this paper summarize the features of temperature control and crack-proof for RCC dam and the primary cause producing the cracks, also, list the rank of crack kinds according to their endangerment to dam body. Meanwhile, some important problems in temperature control and crack prevention for RCC dam are discussed, thereby revealing that the active temperature control standard in our country is too strict andcomplex temperature control measures are not necessary for RCC dam, and so forth. According to above conclusions, a series of reasonable temperature control and crack-proof measures for RCC dam are provided, which will be useful for reference in the aspect of temperature control design and crack-proof measures for RCC dam.