Practical procedure for predicting non-uniform temperature on the exposed face of arch dams

Temperature distribution on the exposed face (especially the downstream face) of arch dams is non-uniform, to a certain extent, due to the variation in solar radiation striking the surface. However, the temperature at the same elevation across the dam axis is generally assumed to be uniform in the design specifications for arch dams because there is no accepted procedure for defining the non-uniform temperature field. In this paper, a practical model for predicting the non-uniform temperature of the exposed face is presented by considering both solar radiation and shading effects. The ASHRAE clear sky model was adopted to calculate the solar radiation, and a ray-tracing algorithm was used to analyze the shade of surrounding terrain and the structure per se. The real-life case study presented in this study shows that the proposed model was effective in simulating and accessing reasonable thermal distribution. Subsequently, the case study also reveals that the non-uniform temperature had a significant effect on surface thermal stress and crack propagation. (C) 2010 Elsevier Ltd. All rights reserved.