Laboratory Test and Numerical Simulation of Time-Dependent Thermomechanical Behavior of the Three-Gorges Dam

Abstract

The evaluation on the risk of thermal-induced cracking is among the key issues in the design and construction of the Three-Gorges Dam. The time-dependent thermomechanical behavior of the left guide-wall section of the dam is systematically studied. A series of laboratory tests on the concrete thermomechanical properties are conducted. A three-dimensional finite element code is developed for calculating the evolutionary temperature and stress field of the dam. The time-dependent thermomechanical properties of concrete, detailed construction procedures, variations of environmental temperature, and the effects of water cooling are taken into account in this code. The distribution and evolution of temperature and thermal stress of the dam are derived. The superimposed effects of thermal load, self-weight, and external water pressure are discussed. The results indicate that the thermal tensile stresses can be largely counteracted by the compressive stresses due to self-weight. There is very little cracking potential after reservoir filling. Nevertheless, during the construction, large tensile stresses can be locally caused; accordingly, some significant suggestions for the thermal stress and temperature control of the dam are presented.