Arrowrock Dam Mid-Level Outlet Works Rehabilitation 48-inch Clamshell GateConcept. 1:10.67 Scale Physical Model Study

摘要

The Bureau of Reclamation Water Resources Research Laboratory in Denver,Colorado, conducted a 1:10.67 Froude-scale physical model study of the Arrowrock Dam outlet works clamshell gate concept-Hydrostatic and hydrodynamic loading on the proposed gate-house structure during submerged operating conditions was determined. The maximum static pressure differentiated across any part of the structure did not exceed 2.5 feet of water (1.2lb/in2). The peak external dynamic pressure differential did not exceed 1.0 foot of water (0.44lb/in2). Thus, a minimum total pressure differential of 3.5 feet of water (2.0-lb/in2) represents an adequate design value for the gate-house structure. Inrternal pressure differentials were also determined. The maximum internal static pressure did not exceed 0.75 foot of water (0.32 lb/in2) and the peak internal dynamic pressure differential did not exceed 1.0 foot of water (0.44 lb/in2). Thus, the total internal load across the top of the gate-house structure is not expected to exceed 1.75 feet of water (0.75 lb/in2). Surface vortices were obtained during model operation submergences of prototypes below tailwater elevation 3035 feet. Although undesirable, such conditions are not expected to influence prototype performance of the clamshell gates.