Minimizing Storm Damage To Operating Houses on Movable Bridges Brett M. Brabham, P.E. Louisiana Department of Transportation and Development Bridge Design Section
Introduction 150 Movable Bridges (Excluding Railroad) Vast majority have Operating Houses New Operating Houses cost between $400k to $500k Not included in this estimate is $120k of electrical equipment
Codes and Regulations AASHTO has minimal information concerning the construction of Operating Houses Louisiana has adopted National and State codes for the construction of buildings
Code Requirements for Buildings in Louisiana International Building Code National Fire Protection Association (NFPA) Code Louisiana Plumbing Code The American Society of Heating, Refrigerating and Air- Conditioning Engineers (ASHRAE)
International Building Code Load Requirements 1. Snow Loads
Snow Load Map
International Building Code Load Requirements 1. Snow Loads 2. Flood Loads
Flood Loads Flood Elevations are determined by the Federal Emergency Management Agency (FEMA) Local Jurisdiction
International Building Code Design Flood Conditions All new construction of buildings, structures, and portions of buildings including substantial improvement and restoration of substantial damage to buildings and structures, shall be designed and constructed to resist the effects of flood hazards and flood loads.
International Building Code Design Flood Conditions Substantial Damage damage of any origin sustained by a structure to its before-damaged condition would equal or exceed 50% of the market value of the structure before the damage occurred.
What is the criteria for Determining Flood Zones? Area with a flood plain subject to a 1% or greater chance of flooding in any year; or Area designated as a flood hazard area on a community s flood hazard map, or otherwise legally designated.
Bayou Liberty Bridge Former Operating House House Design Elevation is 5. The 100 year Flood Elevation is 7.12.
Bayou Liberty Bridge New Operating House New Operating House Elev. 15.00
Existing Structures Below the 100 Year Flood Plain without Substantial Damage? Flood Resistant Materials
Flood Resistant Materials Use items which water will have little or no effect.
Existing Structures in Flood Zones without Substantial Damage? Flood Resistant Materials Raise items off the floor
Existing Structures in Flood Zones without Substantial Damage? Flood Resistant Materials Raise items off the floor Protective walls
Protective Walls Keep visibility in mind. Provide a bilge Pumping System.
International Building Code Load Requirements 1. Snow Loads 2. Flood Loads 3. Wind Loads
Wind Load Map
Wind Load Building Connections
Roofing Systems Built-up Roofing Systems Metal Roofing Systems
Roofing Systems The most important component in regards to wind-related storm damage. Ensure the wall/ceiling to roof connections can withstand the wind loads.
Roofing Systems
Roofing Systems The most important Component in regards to Wind Related Storm Damage. Ensure the wall/ceiling to roof connections can withstand the wind loads. Ensure that the roof panels/ shingles are installed as per the manf. Recommendations.
Roofing Systems
Roofing Systems Cont. Written Manufacturer s Warranties Corrosion resistant materials including fasteners.
Roofing Systems Consider your environment High Humidity Salt Spray
Roofing Systems Cont. Written Manufacturer s Warranties Corrosion resistant materials including fasteners. Make sure the roof drains properly.
Roofing Systems
Roofing Systems Cont. Written Manufacturer s Warranties Corrosion resistant materials including fasteners. Make sure the roof drains properly. Make sure all items attached to the roof are properly installed such as fans, rooftop units, etc.
Roofing Systems
Window Systems Storefront Systems Individual Windows
Window Systems Must meet IBC wind loads in the building location. Corrosion resistant materials including fasteners. In areas with a wind load of 120 mph or greater, the windows must be large missile impact rated.
Window Systems Cont. Must be installed as per the manufacturer s recommendations.
Window Systems
Window Systems Cont. Must be installed as per the manufacturer s recommendations. Glass must be shatterproof as per AASHTO requirements.
Miscellaneous Components Window Units External Ductwork External Piping
Window Units Make sure the air conditioning unit is secured to the building.
External Ductwork Make sure the ductwork is secured to handle the wind loads in the area.
External Ductwork Although the ductwork was securely mounted to the roof, damage occurred due to the ductwork itself failing.
External Piping Avoid using PVC piping exposed above ground. Piping should be rigidly supported to the bridge with marine grade fasteners.
Summary Know your location within the state prior to designing the building. Know the building elevation for both Flood and Wind Load Design. Use materials based on your environment. Make sure all building connections and components meet wind load requirements. Secure all external items to resist the wind/flood loads in the location of the Operating House.
Questions?