12 Special Structured And Design Features Flashcards
Early high rise buildings
End of 19th century construction, possible because of steel construction and elevators.
Early highrise didn’t have hvac, ventilation was done by
Opening windows.
Early highrise feature that caused extension and smoke spread
Open stairwells and elevator shafts.
Early highrise protection was only from standpipes, when were sprinklers and detection devices introduced.
Last quarter of 20th century.
Earliest highrise buildings were usually not more than what height
10 or 12 stories.
1920-39 saw construction of highrises over what height
40 stories, Empire State 1930 was 102 stories.
Breaking highrise windows is risky because
Falling glass to people below
What reduces upward flow of combustion products in modern high rises
Enclosed stairs and elevator shafts.
Modern highrise fire rating for structural and floor
2-3 hrs for structural members and 2 for floor.
Required fire protection systems by model building code.
Sprinklers, voice Evac system, smoke control system, fire department communication system
Building codes have requires sprinklers and standpipes since
1970s
Elevation increase and increased friction loss is a problem for highrise. For 300’ bulling what would pressure need to be for 100 psi at the standpipe connection.
130 for friction loss. 100 for nozzle , 230 total.
Nfpa 14 requires pressure regulators at standpipe connection if pressure exceeds
100 psi for 1.5” connections
Or static pressure exceeding 175 for larger
Pressure reducers are required on standpipe connection because
High pressure required to get proper water flow to upper levels, causing too muc her pressure for hose lines at lower floors.
Fire alarms are required in highrise because
High occupancy
For evacuating high rises in alarm activation, it is not uncommon to evacuate which floors
Floor of activation and above and below only.
Fire department communication systems serve
The lobby as command center, to landings of exit stairways, areas of refuge, elevators, elevator lobbies, emergency generator and fire pump rooms.
Spare fire department communication handsets are typically located
On the fire command center at the main lobby
Typically fire command center of highrise is located where
First floor or level of where fire department usually accesses. Close room 1 hr fire rating
Typical features of highrise fire command center
Voice alarm system control panel
Fd 2 way telephone panel
Fire detection and alarm annunciatior panel
Elevator location and status panel
Sprinkler valve and water flow annunciatior
Emergency and standby power indicator and controls
Fire pump status indicators,
Door lock controls
Public phone access
Smoke management system panel
One model building code requires what addition to the fire command room in a high rise
Work table and building plans
Horizontal extension in high rises depends on
Compartmentation or subdivision
Phase I of elevator ops
Elevator recall from alarm activation to certain floor
Phase II elevator operations
Override, fd operation
Cautions to be taken while using elevator in fire
Maintain radio contact ability
Know visual indicator for impeding elevator problem
Be aware of possible power failure
Never use fire or heat or water damaged elevator
Shunt trip
Sprinklers in elevator mech room or joist way protected by sprinkler. Shuts off power before sprinkler activates.
Phase 1 elevator fund required with service height over
25 ft
If alarm is activated at the primary recall floor where does elevator go in phase I
Alternate floor
All elevator cars must be accounted for at recall during phase I because
A stalled car may have trapped occupants.
What function is deactivated inside the elevator car during phase I recall
Emergency stop, door, and floor controls
During phase II elevator use, what function outside elevator is inoperable
Elevator call button in hallway of elevator lobbies.
Why is the electric eye safety for the elevator door deactivated in phase II
Because it’s manually operated and prevent smoke from keeping it open.
Why is emergency stop button operable in phase II of elevator ops
So firefighters can stop the car if there is a problem
An underground building as defined by some codes is one that
Is 30 or more below main exit underground
Difficulties in underground buildings
Ventilation
Water drainage from fire or sprinkler ops
Access
Rescue of occupants.
Single greatest challenge of controlling underground building fires
Ventilation
Smokeproof enclosures are required for buildings how deep under grade
30 ft or more with only access in elevators and stairs.
Maximum available fire resistance for subway station structural members
4 hrs
Buildings that present similar challenges as underground buildings
Windowless or blank walled buildings
Windowless buildings are typically required to have
Sprinklers
Emergency access openings in windowless buildings typically required
On a minimum Of two sides of upper floors. Readily identifiable and operable from inside and out
Pressure requirement to keep air supported membrane building up
Appx 0.35 psi
Egress in air supported membrane buildings
Airlock vestibule
Air supported structures are typically hoe many levels
One usable level besides possible mezzanine.
To combat wind forces, air supported structures need
Increased internal pressures to resist wind force, sometimes computer controlled
Membrane covered cable and membrane covered frame
One uses cables and masts, other uses metal frame, more common than air membrane but less unobstructed space
Covered mall
Numerous stores facing common hallway fro pedestrian traffic that is covered
A mall, must be at least how wide to allow pedestrian traffic and exit
Minimum 20’
Anchor stores
Major national retail stores used to increase mall appeal, usually at ends , large unprotected openings
Individual mall stores are required to have what fire rating wall between them
One hour, but mostly are unprotected opening to mall walkways.
Smoke control systems are typically not required for one story malls but usually are required for what height malls
2 stories and above
Detention center
Smaller holding facility for inmates before transfer to larger correctional facility
What was invented in correctional facilities to allow for sprinklers that won’t facilitate suicide by hanging
Break away sprinkler heads
Atrium
Open area in building 2 or more stories. Like covered courtyard usually with skylights
High rise building
Any building that exceeds the height of the departments aerial device. Generally more than 75 ft
With atriums, sprinklers may only be required for
The floor connected by the atrium
Code requires atrium have fire rating of
One hour enclosure or glass and sprinklers.
In an atrium 1 hr enclosure rating can be eliminated when
Up to three or more stories
Sprinklers may be omitted in atriums with ceilings higher than
55’
Explosion
A physical or chemical process that results in a rapid release of energy and high pressure gas into environment
Types of building explosions
Chemical rxn like natural gas and air or dust and air
Uncontrolled chemical rxns in plants of unstable compounds
Boiler explosions- physical from over pressure
Damage inflicted form explosion is dependent on
Maximum pressure released
Rate of pressure rise
Duration of peak pressure
Resistance of confining structure
Explosion containment
Building designed with adequate reinforcement to contain pressure form explosion
Venting explosion
Quickly relieve pressure from explosion before it can cause damage. Louver vents, hangar doors, wall panels, windows, roof vents
Explosion vent panels should not weigh more than
3 lbs
Area of refuge for egress stairway is located
With stairway on landing or in adjacent vestibule with room for one or two wheelchairs.
What is often used as an area of refuge
Elevator lobbies
Smoke barrier rating for area of refuge
One hour
Are of refuge should be provided with
Some means of communication
Storage racks can vary from
2-3 tiers, 12 ft tall or over 100’
Rack configuration may cause what problems
Narrow isles so sprinklers can’t get to it,
flues for fire travel between items.
Sprinklers fro racks are determined by
Height and style of racks
Things being stored
Types of containers or pallets
