Concrete Gravity Dams: Coupled Thermal-Stress Numerical Analysis

摘要

During the process of setting-out and hardening in concrete, the temperature profile shows a gradualrnnonlinear distribution due to the development of heat of hydration of cement. At early ages ofrnconcrete structures, this non-linear distribution can have an influence on crack evolution, especiallyrnin mass concrete such as that used in concrete gravity dams. It is thus important to study the factorsrnaffecting the amount of heat generated in the hydration process and minimize it as much as possiblernin order to prevent the generation of undesired cracks through the dam’s body. Coupled thermalstressrnfinite element analysis has been performed on a full-scale concrete gravity dam to determinernthe impact of changing the time intervals in concrete placing schedule on the thermal/stressrnresponse of the dam. The significance of time, material and environmental factors has beenrnscrutinized in this numerical investigation. The investigated parameters are the constructionrnschedule of casting concrete, the cement content and the ambient temperature. The investigationrnalso numerically explored the effect of water pipe cooling of mass concrete on the generatedrntemperature and induced stress in concrete which ends up with recommending the most effectivernstrategy for pipe cooling.