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|Title:||Berryessa Creek channel junctions, Santa Clara County, California : hydraulic model investigation|
|Authors:||United States. Army. Corps of Engineers. Sacramento District.|
Davis, W. Glenn.
|Keywords:||Berryessa Creek (Calif.)|
Los Coches Creek
Santa Clara County
|Publisher:||Hydraulics Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; HL-93-2.|
Abstract: Tests were conducted on a 1:16-scale and two 1:20-scale models of the Berryessa Creek and three of its major tributaries to evaluate the performance of the proposed designs and develop desirable modifications, if needed, to safely pass the 100-year-frequency discharges through the three channel junctions. Specifically, the Sierra Creek, Los Coches Creek, and Piedmont Creek junctions with Berryessa Creek were investigated. The Berryessa/Sierra junction model (1:16 scale) reproduced approximately 500 ft of the Berryessa channel and 200 ft of the Sierra channel. The model was constructed so that the slopes of the channels could be adjusted to reproduce energy gradients equivalent to those resulting from prototype Manning's n values of 0.012 and 0.014. Initial tests, conducted with the invert slopes adjusted to reproduce an energy gradient resulting from a Manning's n value of 0.014, indicated that the original design would effectively convey the design flow (2,680 cfs), and with minor modifications, flow conditions could be improved at the Morrill Avenue box culvert. Tests indicated that flow conditions at the Morrill Avenue box culvert could be improved with the addition of a triangular pier extension. Tests also indicated that with a total discharge of 3,370 cfs (2,670 cfs in Berryessa Creek and 700 cfs in Sierra creek) the Morrill Avenue box culvert would prime (flow full) and significant overtopping would occur upstream from the box culvert. Additional tests were conducted with the invert slopes adjusted to reproduce the energy gradient for a Manning's n value of 0.012. Test results indicated that the original design was adequate to convey the design discharge of 2,680 cfs. Test results also indicated that the Morrill Avenue box culvert would prime for flows greater than 3,770 cfs (2,670 cfs in Berryessa Creek and 1,100 cfs in Sierra Creek), resulting in significant overtopping upstream of the box culvert. The Berryessa/Los Coches Junction model (1:20-scale) reproduced approximately 600 ft of Berryessa Creek and 200 ft of the Los Coches channel. The invert channel slopes were adjusted to reproduce the energy gradient for a Manning's n value of 0.016. Tests to determine the adequacy of channel improvements for the Berryessa/Los Coches Creek junction indicated that for the original design, flow conditions were satisfactory for the design discharge. The Berryessa/Los Coches Creek model was modified somewhat to reproduce the Berryessa/Piedmont junction by removing the bridge and the constriction from sta 108+30 to sta 109+05, and increasing the channel invert of Piedmont to a height of 8.5 ft above the Berryessa invert. Tests to determine the adequacy of channel improvements for the Berryessa/Piedmont Creek junction for a Manning's n value of 0.016 indicated that the original design would effectively convey design flow conditions.
|Rights:||Approved for public release; distribution is unlimited.|
|Appears in Collections:||Miscellaneous Paper|