Study On Temperature Control And Crack Prevention Of High RCC Gravity Dams

Concentrated on the questions of temperature control and crack prevention studies on high RCC gravity dams, simulative calculation theories of temperature and stress fields of high RCC gravity dams are systematically studied in theory and practice, the temperature control of Longtan high RCC gravity dam is analyzed and studied in detail. The main contents are as follows:1. Owing to multi-lift characteristics of high RCC gravity dams, great efforts of calculative work should be taken for computing 3-D temperature and stress fields of the dams. A non-homogeneous multi-laminate element model is put forward to reduce the efforts, making 3-D simulative calculation of high RCC gravity dams realized. Using the model not only makes theory rigid in simulative calculation of temperature and stress fields, but more precise in calculative results, resolving the difficult problems of large-scale in simulative calculation of high RCC gravity dams.2. A back analysis method for multi-parameter identification of concrete is suggested; it needs simple testing equipments only, costs little, and reduces the difficulty of test.3. The FEM equations of computing water temperature in cooling water pipe are deduced by the principle of water-body heat quantity equilibrium to resolve the problem of water pipe cooling in mass concrete. Using the solution of three-dimensional FEM iteration method makes 3-D temperature field calculation of water pipe cooling in high RCCD more precise.4. Based on the simulation model theory of temperature and stress fields presented in this article, a large simulating program for high RCCD has been developed, which can numerically simulate all kinds of temperature control measures, including water pipe cooling, heat insulating in winter, reducing place temperature of concrete, spraying water brume, and long interval over-watering surfaces overflowing in flood season..5. Based on Longtan project, temperature control and crack prevention of a typical overflow section block of the high RCC gravity dam is studied as a case study.