Behaviour of a weir under earthquake loading

The effects of Earthquake driven stress on a weir cross section in a trench in the solid rock at the bed of the river was studied. A two dimensional approach on the weir cross section using SAP 2000 (1998) finite element code was applied and the four-node quadrilateral isoparametric elements in the analysis was also used. The weir considered was made of Grade 25 concrete where Young's modulus and the Poisson ratio of the concrete were taken as 24 KN/mm 2 and 0.2 respectively. The study to analyze a ultimate limit state also considered the combinations of earthquake action ranging from 0.1g to 0.5 g of ground acceleration in the flow direction and lateral flow direction . The study showed that the tensile stresses in the upstream area of the weir increases with the increase of ground acceleration and reaches to top at upstream toe.