Thermal deformation coordination analysis of CC-RCC combined dam structure during construction and operation periods

The combined dam structure is constructed by large volume conventional concrete and roller compacted concrete. The differences of the thermodynamic properties of different concrete materials are the primary causes of deformation coordination problem of concrete dam. The finite element method is adopted to calculate the temperature-stress field during construction and operation periods of the combined damming structure according to the experimental results of different concrete and the construction schedule of combined dam structure. The validity and reliability of the calculation results are verified by long-term actual monitoring temperature. During the construction and operation of the dam, the evolution law of temperature field is considered under the action of environmental temperature, water temperature, concrete hydration heat, concrete heat dissipation performance and water pipe cooling. By coupling the temperature field with the structural stress field, the deformation coordination of materials in dam partitions and the non-linear contact behavior of interface are analyzed. The results show that in the aspect of temperature control, the temperature stratification is obvious in the early stage of concrete pouring, and tends to be stable in the later stage. The upstream surface of the dam is greatly affected by the temperature of reservoir water. In dam deformation coordination and interface contact, the displacement value along the river direction is greatly affected by the upstream water level, showing a significant positive correlation. There are differences in relative displacements of different areas, so we should pay more attention to the change of regional displacements in safety monitoring.