Design and Construction of Gates/Bulkheads
Bulkheads
“A bulkhead or stoplog and guides should be provided at the entrance to each water passage for dewatering the service and emergency gates for maintenance except when they are excessively costly or clearly unfeasible and other means can be improvised. When emergency gates are not required, stoplog or bulkhead guides for maintenance should always be provided upstream of the service gates”.[1]
Gates
“Controlled spillways include crest gates that serve as a movable damming surface allowing the spillway crest to be located below the normal operating level of a reservoir or channel”.[2]
“Gates are composed primarily of structural steel and are generally of welded fabrication. Structural members are typically rolled sections; however, welded built-up girders may be required for large gates”.[2]
“The hydraulic engineer will normally establish the limiting parameters for gate height and width. Within those limits, various height-to-width ratios should be studied to find the most suitable gate size for the project. The structural designer should coordinate closely with the hydraulic engineer in determining the basic limiting requirements for size and shape. The size, shape, and framing system of the gates should be selected to minimize the overall cost of the spillway, rather than the gate itself. Determination of gate size will also consider practical operation and maintenance considerations specific to the project”.[2]
“The gate width will be determined based on such factors as maximum desirable width of monoliths, length of spillway, bridge spans, drift loading, overall monolith stability, and loads on trunnions and anchorages. On navigation projects, the gates may be set equal to the width of the lock, so that one set of bulkheads can serve both structures. It is usually desirable to use high gates rather than low gates for a given discharge, since the overall spillway width is reduced and results in a more economical spillway”.[2]
“Many new gate designs utilize hydraulic cylinder hoist systems because they are usually cost effective. However, these systems have some disadvantages and are not suited for all applications”.[2]
“A properly designed anchor system will prevent structural cracking of concrete, limit deflections, account for all time-dependent stress losses, and safely accommodate specified loads for the life of the structure”.[2]
Best Practices Resources
Structural Design and Evaluation of Outlet Works (EM 1110-2-2400), USACE
Design of Spillway Tainter Gates (EM 1110-2-2702), USACE
Citations:
Revision ID: 7088
Revision Date: 07/11/2023