Tsunami Damage to Waterfront Infrastructure
Damage and losses like this are so devastating. As a coastal engineer I would like to organize or be part of a network of harbor, marina and dock consultants and interested stakeholders in investigating our existing waterfront infrastructures, find out what survived and what did not, and how we can become wiser in designing and building more resilient infrastructures. Although "brick and mortar" hard, inflexible structures have their purposes, I believe we need to look closer at innovative, flexible, and/or transportable structures to do the best we can to minimize if we can such damage and destruction.
This presentation is my effort to contribute to that process.
1. Designing Resilient and Adaptable Marinas in An Age of Potentially More Violent Weather And Uncertain Economic Times Presented by: Dave Wentland, P.E. Coastal and Environmental Engineer DOCKS & MARINAS, INC. De Pere, Wisconsin USA www.docks-marinas.com In Partnership with: STRUCTURMARINE Marinas Tailored to Your Dreams www.structurmarine.com April 7, 2011 A Webinar Presentation
3. FOR THE RECORD First and Foremost Docks & Marinas, Inc. prides itself on being a fair and objective coastal engineering company Second We continually search for and are willing to partner with equipment and product manufacturers we believe offer the finest products and services in our marine industry Third We believe STRUCTURMARINE is such a company and we are proud to represent it Last The observations, opinions and suggestions in this presentation to possibly reduce future damage to Santa Cruz and Crescent City, California harbors in the aftermath of the March 11, 2011 tsunami are solely those of Docks & Marinas, Inc.
7. DAVID WENTLAND, P.E. President Coastal and Environmental Engineer EDUCATION: MS: Ocean Engineering (Coastal Emphasis) University of Hawaii – 1978 BS: Civil Engineering (Environmental/Construction Emphasis) South Dakota School of Mines & Technology - 1973 REGISTRATIONS: Professional Engineer Wisconsin, Registration # E-20150 Michigan, Registration # 40795 OTHER: Licensed Pilot CREDENTIALS: Certified Diver www.linkedin.com/in/davewentland
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9. Never Be Afraid to Learn
10. Do Not Accept the Status Quo – Always Ask Why
11. Listen
12. Network and Communicate
13. Think Outside the BoxPilot Island, Death’s Door Passage between Door County Peninsula and Washington Island Lake Michigan
14. Thinking Outside the Box: Innovative Products to Help Marinas Become Clean Wisconsin Marina Association WMA & WI Clean Marina Meeting Milwaukee Yacht Club March 10, 2010 This is an example of one of many presentations we give on docks, marinas, harbors, and coastal topics. Shown is the Sawyer Park Harbor of Refuge in Door County, Wisconsin designed by Dave Wentland, P.E. Recent Conferences, Presentations and Trade Shows Docks and Marinas Conference in Madison, WI in October 2010Floating Island International (FII) Symposium in Montana in October 2010Marina Recreation Association (MRA) conference in Las Vegas in November 2010International Marina and Boatyard Conference (IMBC) in Ft. Lauderdale in January 2011Wisconsin State Cranberry Growers Association (WSCGA) conference in Stevens Point, WI in January 2011Wisconsin Marina Association (WMA) meeting in Sheboygan, WI in February 2011
15. ASK WHY Why Is Sand Pumped On the Accretion Side of the Harbor Breakwater ? Ontonagon, Michigan Lake Superior Photographed by David Wentland P.E. Docks & Marinas, Inc.
16. How Do We Deal With These Waterfront Issues?Extreme Low Water LevelsRotting Infrastructure Photographed by David Wentland P.E. Docks & Marinas, Inc. Kewaunee, Wisconsin Harbor Lake Michigan
17. How Do We Deal With This Issue? Corrosion has been eating away at steel pilings in Duluth-Superior harbor for over 30 years, consuming an estimated 50,000 plus pounds of steel a year. Once identified in the late 1990s, scientists, engineers and local dock owners (led by the Port Authority) immediately began researching potential causes and ways to either stop it or protect remaining steel structures. “Factors Contributing to Corrosion of Steel Pilings in Duluth-Superior Harbor” (by R. Ray, J. Lee and B. Little), this research demonstrates a specific sequence of biological, chemical and physical events responsible for localized corrosion of carbon steel piling – including the role ice scour plays in accelerating that process. Duluth-Superior Harbor and Many Other Harbors on Lake Superior With Steel Waterfront Infrastructure are Being Affected
22. Article in Current Issue Of Marina World March/April 2011 “But marinas can’t be approached like commercial ports – they are more complex, require more disciplines, extra design elements and have a different kind of environmental importance.”
23. Sturgeon Bay, Wisconsin USA Yacht Made of Welded Aluminum (If Preferred for Ships, Then Why Not for Docks) LEARN FROM OTHERS! ALUMINUM IS USED IN BOAT BUILDING Manitowoc, Wisconsin USA
24. ALUMINUM IS USED IN AIRCRAFT WHY ARE AIRPLANES BUILT OF ALUMINUM? Airplanes need to be light and flexible to perform well in flight. Weight Aluminum is a light metal. Flexibility Aluminum is flexible. As an airplane flies, especially pressurized aircraft, the skin must be able to flex both due to the buffeting of the air and due to internal pressure increases and decreases. Bendability Aluminum is easily formed into curved shapes that are more aerodynamically sound. Workability Because it is light, flexible, and easy to bend, aluminum is easy to work. Corrosion Resistant Aluminum is more resistant to corrosion. It reacts more slowly to air, so it will not rust like steel or other ferrous metals. Cost Because of the benefits of aluminum, it is the cheapest material available that will serve the engineering requirements.
28. WAVE REDUCTION SYSTEMS (WRS) STRUCTURMARINE is at the forefront of WRS development. It offers several types, which have been rigorously tested over the years. Built to the same standards as its docks, they are built for efficiency – up to 90% wave attenuation – and to last a minimum of 25 years. In addition whenever possible, they are built to be multi-functional, and be revenue generators. It looks for what’s possible and sees what the opportunities are. “Change is an opportunity. We must embrace the change, work with it and become comfortable with it. We have to look for what’s possible and see what the opportunities are.” Part of keynote address given by Vince Morvillo Motivational Speaker and Owner Sea Lake Yacht Sales 2011 IMBC BE ADAPTABLE AND MULTI-FUNCTIONAL A Stand-alone Wave Attenuator Was in the Bid Documents Structurmarine Proposed a WRS which included Additional Dockage to Add Additional Revenue Generation
38. Santa Cruz and Crescent City, California harbors in the aftermath of the March 11, 2011 tsunami Observations, Opinions and Suggestions by Docks & Marinas, Inc.
42. SANTA CRUZ HARBOR Inlet to Bridge “Port Director Lisa Ekers revised her estimate to $22.5 million in tsunami-related damage to Santa Cruz Harbor, up from $17 million, the Santa Cruz Sentinel reported. Ekers told the newspaper the final figure cost could be more than $25 million. The figure includes the expected cost of rebuilding damaged docks and other infrastructure but not an additional $4 million in damage to private vessels.” WIVB.com 3/16/2011 2011 Google
47. CRESCENT CITY HARBOR The Marina “Total damage estimate $38.5M Written by Megan Hansen, The Triplicate March 30, 2011 06:34 pm Harbor cleanup continues while fed funds sought. Damage estimates for Crescent City’s harbor exceed $38.5 million and $16 million can be attributed to the recent tsunami, Harbormaster Richard Young said Tuesday. The harbor previously sustained $22.5 million in damages during a tsunami in 2006 — after which the state declared the harbor an emergency and allocated funds from the California Emergency Management Agency. 2011 Google
51. OBSERVATIONS Both harbors have been damaged by tsunamis in the past. Why is this? Might their locations and physical layouts be factors? What changes have been made after previous “events” causing damage? The marina /harbor in Santa Cruz and marina in Crescent City have narrow entrances. As the “external” ocean level changes rapidly the water in the “box” will try to equalize the difference but is restricted by the size of the entrance. Current (water velocity) must increase dramatically to compensate. Q = VA or V = Q/A As long as the only water route is through the entrance the direction of the current will be relatively consistent. The rate of change of the “external” water level will affect the velocity of the current. This may affect whether the flow is more turbulent than laminar which would affect how the water propagates within the “box”. Eddies on the lower water side of the entrance will also behave differently. The floating dock layouts appear to have been determined based on maximizing the # of boat slips, rather than streamlining the structures relative to the currents to reduce lateral loads. Floating docks appear to be heavy structures because of the extensive amount of flotation keeping them floating. Anchorage is vertical piles.
52. OPINIONS Each “event” that causes damage needs to be a learning experience, and adjustments made. Natural forces often exceed what we can design and build. How do we deal with that reality? Can we design flexible, “resilient” marinas? LOCATION, LOCATION, LOCATION. Just as in landside real estate, each location is “site specific”. Some locations are much better than others. We need to recognize the distinctions from experience and training. Many of the less challenging locations have been already adapted and altered for our use. Developing locations today requires far more knowledge than luck. Layouts, structures and anchorage need to be designed and built recognizing past events and our knowledge of potential natural forces. Risk of damage is inversely related to costs. The more we know about a site the better our design. Generally quality in, quality out. Knowledge of soils, land elevations, water depths, water levels, waves, sediment transport, circulation, land drainage, contamination are examples. Intended short-term and long-term uses, desired useful life, and expected maintenance are crucial. Things change. Basing future events on past (historical) events is no longer as dependable as we used to believe. The sizes of, and reasons for, boats will not be the same over time. The same is true where we keep them.
53. OPINIONS continued: When you have a “box” with a small entrance, is it possible to install a door at the entrance? This is done on river locks, to eliminate, or nearly eliminate, the water trying to maintain the same level inside and outside the “box”. Can a larger or additional openings be constructed to increase the area (A). V = Q/A. The larger the area, the less the velocity. The tradeoff is whether doing so will create an unacceptable wave climate in the marina. Typically a resident one foot wave is acceptable in a marina. Sometimes a two foot wave is acceptable. It depends on the size of boats, flexibility of dockage, and user preferences. Can the dockage and boats, or at least the boats, be moved out of harms way? What areas in a marina are protected by solid structures where boats can be sheltered away from dangerous currents? Are there access areas, like launch ramps or travel lifts, where boats can be removed as soon as an alarm is given? How soon is an alarm given? I read that there was about a four hour window of time from the time of the earthquake in Japan until the tsunami reached Santa Cruz and Crescent City. Was there an emergency preparedness plan to reduce potential damage? Was it implemented? Given the damage that resulted, can it be improved?
54. SUGGESTIONS We are observing, researching and learning about our planet as never before. Combined with our “information highway” we have the greatest amount of knowledge and resources for educated decisions. Do not design marinas based only on the past (hindcasting). Consider what may be events in the future and plan wisely. Layout marinas and floating structures to minimize vertical and horizontal loads. Streamline the profiles to reduce horizontal forces. Fish, boats, birds and airplanes are examples of such designs. Minimize the weight of floating docks so as little flotation as possible is needed. Less flotation means less current forces against the docks. Boats have better profiles than docks. The goal is not to feel like you are “walking on land”. Rather to get safely to your boat. Floating concrete docks are heavy and rigid . They need more flotation and will often break rather than bend. Build docks of materials that are lighter and able to flex without breaking. “All wood” docks wear out too fast where bolts are fastened to wood. Use anchorage that is not rigid but flexible. When possible use “chain and bottom anchor” or elastic anchorage instead of rigid pilings. As water level changes, ensure dock connections to anchors do not bind. Boat lines to dock cleats, docks connections to anchorage, and anchors to the harbor bottom are the points of concentrated loadings. Use shock absorbing materials and strong connections to transfer those loads through the entire dock system.
55. THE FUNDAMENTALS OF FLOATING DOCK DESIGN NEWTON’S LAWS OF MOTION FLOATING STRUCTURES HAVE SIX DEGREES OF FREEDOM MOTIONS
56. NEWTON’S FIRST LAW OF MOTION AN OBJECT AT REST WILL REMAIN AT REST … AN OBJECT IN MOTION CONTINUES IN MOTION WITH THE SAME SPEED AND IN THE SAME DIRECTION UNLESS ACTED UPON BY AN UNBALANCED FORCE NEWTON’S LAWS OF MOTION IMPORTANT PRINCIPLES WHEN DESIGNING FLOATING STRUCTURES NEWTON’S SECOND LAW OF MOTION ACCELERATION IS PRODUCED WHEN A FORCE ACTS AS A MASS NEWTON’S THIRD LAW OF MOTION FOR EVERY ACTION THERE IS AN EQUAL AND OPPOSITE REACTION
57. FLOATING STRUCTURES UNANCHORED HAVE SIX DEGREES OF FREEDOM MOTIONS IMPORTANT PRINCIPLES WHEN DESIGNING FLOATING STRUCTURES
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59. Easy to connect and disconnect
60. Interchangeable sections
61. MultifunctionalTapered finger docks for reduced lateral forces, more strength, and more boat capacity Structural frame Make the dock only as stable as acceptable but no more than that. A heavier than necessary dock needs more flotation in the water. More material also costs more money. . The more openings in the water, the better the water circulation in a marina which means better water quality, and less accumulation of debris Minimum amount of flotation in the water Flexjoint connector blocks (shock absorbers)
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63. INTENDED PURPOSE
64. RISK (WHAT’S THE CHANCE IT COULD BE DAMAGED)
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66. What’s the risk if it is damaged? If the investment of time and cost is modest, so will be the repairs.
67. It appears to be built of readily available materials at reasonable or no costTHERE MAY BE AN IMPORTANT LESSON HERE. Learn to notice what works. Include that knowledge , along with your training, to design resilient and adaptable marinas. Island of Roatan in Honduras Photographed by David Wentland P.E. Docks & Marinas, Inc.