Appendix C Presentations This appendix provides the MS Word PowerPoint presentations of the state-of-practice regarding dam service and/or emergency spillways. All the presentations presented at the workshop are included in this appendix as documentation of the state-of-practice and research needs as seen by the presenting experts. FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways 1 Presentation 1: Hydraulic Design of Labyrinth Weirs and Fuse Gates FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways 3 Hydraulic Design Of Labyrinth Weirs Henry T. Falvey & Associates, Inc. 0utline of Presentation Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Types of Weirs Side Channel Skew Folded, Accordion, or Corrugated Duckbill or Bathtub Labyrinth Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Nappe Interference Streamline 3-D View Weir Crest Disturbed Area PLAN Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Effective Disturbance Length (1-Cm)Ld = Lde Effective Disturbance Length Interference Effects Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Design Curves – Lux/Hinchliff Henry T. Falvey & Associates, Inc. Design Curve - Tullis Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Nappe Oscillation - Milton Reservoir Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Solutions to Nappe Oscillation FLOW - FLOW - Radius Angle Iron FLOW - FLOW - Splitter Roughness Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Geometric Definitions Design Considerations - New versus Old * Lux recommends 0.45 < Ho/P < 0.55 W/P = 2.5, and 2 < L/W < 6. * New criteria allows Ho/P to be as high as 0.90, W/P is superceded by interference ratio (Lde/L) and L/W superceded by efficacy. Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Design Considerations - Efficacy Efficacy Sidewall Angle, degrees Henry T. Falvey & Associates, Inc. Design Considerations - Position Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Research Needs * Crest Shape * Interference Verification * Need for Splitters on Crest * Approach Flow Considerations * Raised Invert Effects Henry T. Falvey & Associates, Inc. FUSEGATES Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Fusegate Geometry Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Profile Tilting Range Ballast Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Elevation Ballast Crest Length = 5.22 H Henry T. Falvey & Associates, Inc. Forces on Fusegate Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Moments on Fusegates Tipping Range Flow Begins to Overtop Gate Restoring Moment Overturning Moment Water Surface Height ( H - h ) / H Henry T. Falvey & Associates, Inc. Fusegate Chamber Pressures Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Discharge Characteristics Rehbock Equation Henry T. Falvey & Associates, Inc. Issues with Fusegates * Wave loading has been studied * Ice loading has been studied * Seismic loading has been studied * Tailwater effect has been studied * Downstream channel clogging has been studied * No major research needs Henry T. Falvey & Associates, Inc. FEMA Workshop - Issues. Remedies and Research Needs Relating to Service and/or Emergency Spillways Presentation 2: Fuse Plug Embankments -State of the Art and Practice, and Research Needs 16 FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Fuse Plug Embankments State of the Art and Practice, and Research Needs Tony Wahl Bureau of Reclamation Water Resources Research Laboratory * Design concept by Tinney and Hsu (1961) - Proven in their lab tests, Oxbow field test, and 1980’s Reclamation lab tests * Core is inclined downstream - Failure is by scouring out non-cohesive supporting zone, causing core to be a cantilevered beam - Initiation is reliable, rapid - Lateral erosion rate is predictable, depends on head and embankment cross section 16 FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Design Concept Laboratory Testing State of the Practice * How many have been built (or are being built)? * What design concept are they using? - Tinney & Hsu inclined core - More traditional embankments - Vertical core or homogeneous fill * Operational history State of the Practice * Reclamation fuse plugs - Horseshoe and Bartlett Dams - 262,000 cfs (~10 yrs) - New Waddell Dam - 5,500 cfs (~10 yrs) - Sumner Dam - 150,000 cfs (1955) 16 FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Fuse Plug at New Waddell State of the Practice * Fuse Plugs Built by Others - Center Hill Dam (USACE) (USBR consulted) - Lake Pontchartrain fuse plug levee (1936) - Yahekuo Dam, China (vertical, tapered core) - Fuse plugs reported to be widely used in China - Arvada Reservoir (10- bay homogeneous embankment) considering rehab - Manny, many small dams - e.g., 4 dams North Carolina (Nantahala Power) FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Operating History * Very few spillways have operated - Oxbow Field Test was a prototype - Fuse plug at Silver Lake on Dead River in Upper Peninsula of Michigan failed (?) in May 2003. - Greater portion than anticipated gave way - Apparently eroded too deep… no fixed sill - Nobody I talked to was willing to say much right now Research Needs * Investigating long-term stability of inclined clay core - Cracking due to dessication bi differential settlement - issues of concern on SRP fuse plugs - Contact with floor and side walls - Is long-term water storage against a fuse plug desirable, undesirable, or not an issue? FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Research Needs * Designs utilizing other materials that might offer better long-term performance or ease of construction - Impermeable membranes - Inclined concrete core * Research to define inventory of fuse Plug spillways, their design concepts, And operational histories FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Presentation 3: Crest Parapets and Dam Raising FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Crest Parapets/Dam Raising Dwayne Fuller U.S. Army Corps of Engineers Engineer Research and Development Coastal and Hydraulics Laboratory Recent Projects * Tygart Dam, Tygart River, West Virginia, Pittsburgh District * Original Design Flow, 270,000 cfs * PMF Flow, 373,000 cfs * 38% increase * Bluestone Lake Dam, New River, West Virginia, Huntington District * Original Design Flow, 430,000 cfs * PMF Flow, 950,00 cfs * 120% increase FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Typical Model Objectives * Extend rating curve * Crest pressures * Gate and pier pressures * Energy dissipation component forces * Stilling basin forces * Scour pad forces * Tailrace sour Tygart Dam Alternatives * No action * Raising the dam (approximately 6’) * Spillway medication (gated spillway with lower crest) * Auxiliary spillway * Overtopping * Dam replacement FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Tygart Dam 1:60 Scale Model Tygart Dam Flows With Existing Structure FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Tygart Dam Redirected Spill Tygart Dam FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Bluestone Lake Dam 1:65 Scale Model Bluestone Lake Dam Alternatives * No action * Raising the dam (approximately 14’) * Spillway modification * Auxiliary spillway * Overtopping (partial) * Dam replacement FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Bluestone Lake Dam Original Design Flow High Flow Concerns * Spill capacity (PMF passage) * Stilling basin * Cavitation (spillway and penstocks) * Erosion * Component inadequacy * Hydraulic loads - Forces on side walls - Basin forces - Forces on temporary structures * Flow conditions in tailrace * Debris build-up in basin (side flow) FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways Possible Research Needs * Effects of side flow into stilling basin * Debris damage in basin * Force measurement techniques * Temporary structure design criteria FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways Presentation 4: Gated Spillways: Enlargement, Modification, and Rehabilitation -State of the Practice FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways GATED SPILLWAYS Enlargement, Modification And Rehabilitation State of the Practice GATED SPILLWAYS * Determine Function and Needs * Risk Neutral * Types * Design & Research Needs FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways DETERMINE FUNCTION AND NEEDS * High Head vs. Low Head * River Flows * Storage Issues of Large Floods (>100 Yr) * Maintenance * Attendance issues DESIGN AND DATA NEEDS * River Flows - Normal - Annual river flows - Minimum Flows - Is a bypass needed? - Maximum Flows * Storm Storage FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways DESIGN AND DATA NEEDS (cont) * Climatic Conditions - Temperature changes - Winter Conditions * Reservoir fluctuations * Vandalism * Security Issues * Debris DESIGN AND DATA NEEDS (cont) * Controls & Automation - operate - remotely or onsite * Emergency power * Flow measuring capability FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways TYPES * Slide Gates * Wheel Gates * Radial Gates * Drum Gates * Crest Gate * Rubber Dams * Fusegates * Flashboards Slide Gates (Unbonneted) FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways Wheel Gates Radial Gates FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways Top Seal Radial Gates Drum Gate FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways Crest Gate (Obermeyer Gate) Rubber Dams FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways Fusegates (Hydroplus) Other Types of Gates * Flashboards * Cylinder Gates * Other FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways RESEARCH NEEDS * Discharge data * Submergence effects on discharge * Extrapolation to other situations * Flows released during failure * Seismic and security modifications * Cost * Maintenance and Durability FEMA Workshop - Issues, Remedies and Research Needs Relating to service and/or Emergency Spillways