Please use this identifier to cite or link to this item:
|Title:||Outlet works for Cerrillos Dam, Cerrillos River, and Portugues Dam, Portugues River, Puerto Rico : hydraulic model investigation|
|Authors:||United States. Army. Corps of Engineers. Jacksonville District.|
George, John F.
|Publisher:||Hydraulics Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Technical report (U.S. Army Engineer Waterways Experiment Station) ; HL-79-6.|
Abstract: Tests were conducted on a 1:24- scale model of the outlet works for the Cerrillos and Portugues Dams located in Puerto Rico. The purpose of the model investigation was to determine the performance of the stilling basins for the full range of discharges with minimum head pool and the optimum riprap protection plan for the exit channel. The model reproduced a schematic of the intake tower, conduit transition, 60 percent of the conduit length, the stilling basins, and exit channel. The original design stilling basin (type 1) for the Cerrillos outlet works performed satisfactorily for low discharges of 500 cfs and less, and for the higher range of discharges between 1500 and 2500 cfs (design discharge). However, with the intermediate discharge of 1000 cfs, eddy conditions developed. Recommended modifications (type 14 stilling basin) incorporated into the original design included extending the invert immediately downstream from the outlet portal horizontally for 10 ft, raising the basin apron, relocating and reducing the size of the baffle blocks, and terminating the basin with a sloping end sill. These modifications produced satisfactory flow conditions for the full range of discharges. The optimum riprap protection plan was developed for the exit channel. Performance of the type 1 stilling basin design for the Portugues outlet works was generally satisfactory with discharges ranging from 250 to 1100 cfs (design discharge). Eddy conditions did not develop for any discharge observed, but the water surface in the basin was rougher with the design discharge of 1100 cfs than that desired. Recommended modifications (type 4 stilling basin) incorporated into the original design included extending the invert immediately downstream from the outlet portal horizontally 10 ft, reducing the width of the baffle blocks, and terminating the basin with a sloping end sill. The overall length of the structure was increased 10 ft to retain the original apron length. The optimum riprap plan was also determined for the exit channel. The conduits of both Cerrillos and Portugues outlet works were designed to provide for river diversion during construction of the dams. When the dams are completed, the flow will be regulated so that only bank-full capacities will be passed through the stilling basins. The conduit capacities were 4500 cfs for Cerrillos and 5300 cfs for Portugues. However, the stilling basins were designed for 2500 cfs (Cerrillos) and 1100 cfs (Portugues), the bank-full capacities downstream. Therefore, considerable damage to the downstream exit channel will occur should it become necessary to pass the conduit design flow through the outlet works.
|Rights:||Approved for public release; distribution is unlimited.|
|Appears in Collections:||Technical Report|
Files in This Item:
|TR-HL-79-6.pdf||4.96 MB||Adobe PDF|