Theoretical Calculation of RCC Layer Thickness Based on Equivalent Elastic Model and Numerical Study on Dam Deformation

The layer-by-layer construction process of roller-compacted concrete (RCC) leads to the formation of layer zones, resulting in the transversely isotropic constitutive behavior of the RCC dam. Crucially, the thickness of the layer zone exerts a non-negligible influence on the overall deformation behavior of the RCC dam structure. An analytical expression for the thickness of the layer zone is derived based on the equivalent elastic modulus theory, and the influence of concrete with the same and different properties on the thickness of the layer zone is investigated. Numerical analysis is employed in conjunction with the RCC dam project to quantitatively assess the influence of layer thickness on the displacement of the dam structure. The numerical results demonstrate that considering the thickness of the layer zone leads to a substantial increase in both horizontal and vertical displacements of the dam. Furthermore, the range of extreme values of layer thickness is established using the variational principle of elasticity mechanics. When the elastic modulus ratio of RCC with layer zones to bulk concrete β is 0.85–0.99, a reasonable thickness of the layer can be obtained. When the weakening coefficient k and β are close to 1, the thickness of the layer is close to 10 cm, which is close in nature to the RCC dam.