Читать книгу Earthquake Engineering for Concrete Dams - Anil K. Chopra - Страница 49

Wave absorption – or, alternatively, wave refraction – at the reservoir bottom is represented only approximately by the boundary condition of Eq. (A2.10). A hydrodynamic pressure wave impinging on the reservoir bottom results in a reflected hydrodynamic pressure wave in the water and two refracted waves, dilatational and rotational, in the sediments or underlying rock. The angle of reflection is equal to the angle of incidence and the angles of refraction of the two refracted waves are given by Snell's law. Although the boundary condition given by Eq. (A2.10) allows for proper reflection of hydrodynamic pressure waves for any angle of incidence, the only refracted waves allowed in the foundation or in the sediments are downward, vertically propagating waves.