Culver-Goodman Tunnel Control Structure Model Studies

Abstract

The City of Rochester plans to excavate the Culver-Goodman tunnel and connect it to the existing Cross-Irondequoit tunnel through a control structure which will limit the flow diverted for treatment to about 1050 cfs. A 16 ft diameter entrance tunnel with a round to square transition at the downstream end conveys the incoming flow to a distribution chamber. The original design, Type A, distribution chamber is 100 ft long by 76 ft wide, contains 1:1 side slopes, blocks at the upstream end to dissipate some of the energy of the incoming flow, and an ogee crested weir at the downstream end. The floor of the distribution chamber is at elevation 285 ft and the weir crest at elevation 315 ft. Six sluices each 5 ft x 2.5 ft direct the diverted flow downward into the drop chamber. To enter the sluices the incoming flow has to make a 90 degree turn. The 100 ft long by 20 ft wide drop chamber also turns the flow 90 degrees towards the 12 ft diameter exit tunnel. The drop chamber is required to be of sufficient size to dissipate the energy of the falling water and to reduce the flow velocity so that the entrained air in the water-air mixture can rise to the surface and escape. Blocks at the downstream end assist in this process. The floor of the drop chamber is at elevation 216 ft and the top is open to the ground surface. A transition at the entrance to the exit tunnel guides the flow smoothly into the tunnel.