1. Mitigation Milestones

    Today in history:

    Hurricane Donna, September 10, 1960

    View of rooftops left in the wake of Hurricane Donna, Florida, 1960

    State Archives of Florida, Florida Memory; photo Charles Barron

    After Hurricane Donna, communications, hurricane forecasting methods, and shelter facilities improved.  New building construction codes in Florida included mandates for wooden truss rafters, hurricane straps, and concrete-anchored carports.

    To learn more about disaster mitigation, visit Designing for Disaster at the National Building Museum, on view through August 2, 2015. 

     

  2. Mitigation Milestones

    Today in history:

    Galveston Hurricane, September 8, 1900

    Railyard in ruins, Galveston, Texas, 1900

    Library of Congress, George Grantham Bain Collection; photo Bain News Service

    Out of the chaos of this deadly hurricane, Galveston’s citizens pushed through funding for a three-mile long, 17-foot-high seawall.  The city also dredged a canal, raised buildings, and moved infrastructure.

    To learn more about disaster mitigation, visit Designing for Disaster at the National Building Museum, on view through August 2, 2015.

     


  3. Structural Safety Tip: Mind the Gaps

    by Kevin W. Smith, PE, the Engineering Manager for the Expansion Joint Cover Division at Construction Specialties, Inc.

    When we think of buildings, we tend to think of immovable, fixed, and permanent parts of our landscape. But in fact, buildings are meant to move, and are intentionally engineered to withstand and account for natural forces by anticipating and incorporating motion in a variety of ways.

    Movement can be caused by strong winds, of course—especially for taller buildings. Day-to-day movement can also be caused by heating and cooling, which makes the structure expand and contract with temperature change. Settlement is another movement factor. This occurs as the weight of the structure causes the foundation to shift and compact slightly leaving cracks or uneven transitions within a building.

    In discussing natural disaster preparation, however, one of the more sensational forces to account for is movement due to seismic activity (earthquakes).

    Depending on the magnitude of the event, seismic activity can trigger multi-directional movement for a building. Much like a diving board moves with force, during a temblor a building’s weight can shift and become displaced. Unlike a diving board, however, buildings have no springs, and therefore, resilient design must account and compensate for this kind of radical motion with a spring-like system of its own.

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    Building movement, depending on the extent, can create irreparable damage. To mitigate the effects of this movement and to protect the structure and its inhabitants, building designers will incorporate the use of expansion joints. An expansion joint is an engineered, structural gap aimed to accommodate the movement of a building in a controlled manner. Expansion joints can be found in all types of buildings, particularly in earthquake-prone regions. Expansion joints run right through buildings, from top to bottom, front to back. To cover the gap created by this joint, an expansion joint cover is engineered along the top of the two surfaces so that the movement can happen without affecting the adjoining surfaces and without leaving gaps or hazards for occupants. Expansion joint covers mask this internal building safety system, maintaining a seamless and near-invisible layer of protection.

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    At the National Building Museum’s Designing for Disaster exhibition, you can visit the Earth section to see Construction Specialties’ state-of-the-art seismic table. The display features a one-of-a-kind stair system installed on the Berkeley California Memorial Stadium, which sits directly on the Hayward fault. The exhibition illustrates the effects of an earthquake and how expansion joint covers can deliver safety and help mitigate damage by allowing buildings to move and still remain resilient.

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    Designing for Disaster is generously supported by Construction Specialties, Inc.

     


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  5. Mitigation Milestones

    Today in history:

    Hurricane Katrina, August 25–31, 2005

    Flooding, Claiborne and Desire Streets, New Orleans, Louisiana, September 4, 2005

    Federal Emergency Management Agency Photo Library; photo Liz Roll

    After Katrina, levees were brought up to modern building code standards and the U.S. Army Corps of Engineers constructed the Lake Borgne Surge Barrier to reduce the risk of storm surge from the Gulf of Mexico.

    To learn more about disaster mitigation, visit Designing for Disaster at the National Building Museum, on view through August 2, 2015.

     

  6. From Designing for Disaster at the National Building Museum, on view through August 2, 2015:

    Select panels from the ‘Love Can Build Anything’ Hurricane Andrew Mural, 1992

    Mays Middle School students (Goulds, Florida) led by artists Dena Stewart and Stewart Stewart

    Collection of International Hurricane Research Center, Florida International University, Miami, Florida

    When Dena and Stewart Stewart were commissioned to create artwork for the reopening of Miami’s zoo after Hurricane Andrew devastated South Florida on August 24, 1992, they turned to 45 middle schoolers for assistance. With support from their teacher, Barbara Phillips, the students shared their feelings in writing, then were challenged to transform their words into paintings. The tangible result was a powerful, 48-foot-long, movable mural. The intangible: the students had begun the healing process. The mural became a centerpiece at rebuilding ceremonies across the area and a symbol of remembrance and recovery.

     

  7. Mitigation Milestones

    Today in history:

    Hurricane Andrew, August 24, 1992

    Plywood driven through a palm tree, near Homestead, Florida, 1992

    National Oceanic and Atmospheric Administration, National Weather Service Collection

    After Hurricane Andrew, the South Florida Building Code adopted major structural and building component upgrades. One of the most important is the requirement for missile-impact resisting glass, which can withstand high velocity collision with wind-borne debris.

    To learn more about disaster mitigation, visit Designing for Disaster at the National Building Museum, on view through August 2, 2015. 

     

  8. From Designing for Disaster at the National Building Museum, on view through August 2, 2015:

    Fallen finial fragments from the Washington National Cathedral

    Washington, D.C.

    Central Virginia Earthquake, August 23, 2011

    Collection of the Washington National Cathedral

    These limestone fragments are from a pinnacle of a flying buttress on the southeast end of the Washington National Cathedral. Damage to the structure—located some 80 miles from the epicenter of the earthquake—was concentrated in its highest parts, where stones were literally shaken apart. Together with other stone features, the pinnacles help balance the Cathedral’s weight and counter the force of wind. Restoring and reinforcing them is a high priority. The Cathedral sustained a staggering $26 million in damages. Repairs to the nave’s interior have begun, along with work on the flying buttresses that support the exterior apse. Subsequent repairs are dependent on additional funding and will likely take years to complete.

     

  9. These beautiful illustrations map the patterns of one of the world’s most powerful forces - the wind.

     

  10. Mitigation Milestones

    Today in history:

    Big Burn, August 20–21, 1910

    Assessing the damage in Wallace, Idaho, 1910

    Special Collections and Archives, University of Idaho Library, Moscow, Idaho

    The loss of three million acres in Idaho, Washington, and Montana prompted various land-management agencies to emphasize wildfire suppression as an overarching policy. The U.S. Forest Service increased its dedication to fighting every fire.

    To learn more about disaster mitigation, visit Designing for Disaster at the National Building Museum, on view through August 2, 2015.