A Review on Thermo-mechanical Modelling of Arch Dams During Construction and Operation: Effect of the Reference Temperature on the Stress Field

Abstract

Double-curvature dams are unique structures for several reasons. Their behaviour changes significantly after joint grouting, when they turn from a set of independent cantilevers into a monolithic structure with arch effect. The construction process has a relevant influence on the stress state, due to the way in which self-weight loads are transmitted, and to the effect on the dissipation of the hydration heat. Temperature variations in the dam body with respect to those existing at joint grouting generate thermal stresses that may be important in the stress state of the structure. It is thus essential to have a realistic estimate of this thermal field, also called reference or

Anomaly Detection in Dam Behaviour with Machine Learning Classification Models

“…Since the temperature field in the dam body influences the deformations of the dam and depends on the initial temperature considered, we performed a preliminary analysis to obtain a realistic thermal field to be used as the reference temperature in the body of the dam. This is a relevant issue, since thermal displacements are computed on the basis of the difference between these values and the thermal field at each time step of the simulation [16]. For this purpose, we performed a 12-year transitory analysis with a fixed value of the initial temperature (8°C) and a time step of 12 h. The resulting thermal field at the end of this preliminary calculation was taken as the initial temperature for all the scenarios considered.…”

“…A one-way coupling between the thermal and the mechanical problem was applied: the thermal field at the end of the preliminary transient analysis was taken as reference temperature, i.e., deviations from such a value results in thermal deformations; the hydrostatic load is applied and the stress and deformation are computed assuming elastic behaviour; the deformation field is computed as the sum of the thermal and the mechanical deformations. The numerical implementation was developed by the authors and described in detail in [16].…”

Thermo-Mechanical Analysis of Mass Concrete Foundation Slabs at Early Age—Essential Aspects and Experiences from the FE Modelling

“…A basic overview of the main approaches for modelling the behaviour of concrete at early ages and beyond is also provided in RILEM state-of-the-art report [ 27 ]. The investigation on the importance of some factors and numerical aspects in FE models has been recently presented in [ 28 ] for arch dams. Nevertheless, the FE modelling strategy is usually not thoroughly discussed and relies rather on the judgment of researchers performing these calculations, while some aspects involved in the FE analysis can be crucial.…”

FEA of Effects Induced by Diurnal Temperature Variation on Downstream Surface of Xiaowan Arch Dam

“…It is acknowledged that thermal load is one of the important reasons for concrete arch dam cracking, both during construction and operation [1][2][3][4]. During the construction, due to the exothermic reactions, a lot of hydration heat cannot be released in time, resulting in the increase of internal temperature gradient and thermal stress, which leads to cracks.…”

“…Temperature cracks problem was an important research topic in the field of high arch dam structure. To date, lots of achievements [3] related to thermal stress and temperature cracks of concrete dams mainly are focused on the influence of the diurnal temperature variation during the construction [8,9], and the annual temperature [10], seasonal temperature variations [4,11,12], solar radiation [13,14], and water temperature variations [1] during the operation. e results show that the cold wave or the diurnal temperature variation will affect the thermal field within a certain range below the concrete surface and lead to the surface cracks [15].…”