Experimental Study on Water-wing characteristics induced by piers in Flood Drainage Culverts

Setting piers is an effective way to overcome the limits of manufacture and operation of the gates for large span culverts or tunnels. However, the piers, if designed improperly, will bring about water-wing to strike the top and the side walls, and hence affect the operation of hydraulic structures. This present study deals with the water-wing caused by the obstruction of the pier placed in front of a flood drainage culvert. Based on the dimension analysis, the influencing factors of water-wing were analyzed, the hydraulic characteristics were experimentally investigated, and finally a kind of new piers was proposed. The results showed that, it is the initial height of piers that is the key factor, as well as the radius and inclination angle of piers, approached flow velocity and depth.