Post on 17-Jan-2016
Engineering Disasters
Tacoma’s Narrows Bridge- Resonance - The increase in amplitude of
oscillation of an electric or mechanical system exposed to a periodic force whose frequency is equal or very close to the natural undamped frequency of the system.
Engineering Disasters
Teton Dam Failure Breach - A gap or rift, especially in or as if
in a solid structure such as a dike or fortification.
Erosion - material is worn away from the earth's surface.
Settlement of the soil, and seepage were found to be the main causes of the failure.
Engineering Disasters
Korar Bridge Increasing Deflection - The movement of a
structure or structural part as a result of stress.
Stress - An applied force or system of forces that tends to strain or deform a body.
Engineering Disasters
Snellville Billboards Hooks Law/Newtons Law – In order for an
object to remain in equilibrium, it must push back with the same force as being applied to it.
Engineering Disasters
New World Hotel Failure to follow building codes. Corruption of the governmental bodies
issuing permits. Materials could not bare the load.
Engineering Disasters
Silver City Bridge Failure
of pin suspension
System.
Bicycle chain idea!
If one fails, the entire system fails.
Engineering Disasters
Quebec Bridge A grave error was made in assuming the dead load for the
calculations at too low a value...This error was of sufficient magnitude to have required the condemnation of the bridge, even if the details of the lower chords had been of sufficient strength."
Dead load (Dead weight) - The unrelieved weight of a heavy, motionless mass.
Chord - A line segment that joins two points on a curve.
Engineering Disasters
Iran Stadium The load exceeded capacity of the
structure. Hooks Law/Newtons Law.
Engineering Disasters
Walkway Collapse: The change in design increased the load
from 90 kN to 181 kN on the individual bolt. doubled the load, exceeded the capacity on the nut.
Example of conflicting engineers. Too many chefs spoil the soup!
Engineering Disasters
Mianus River Bridge Collapse: Pin failure: Corrosion-dissolution of
bodies, either by an acid or a saline menstruum.
Infrequent inspection.
Engineering Disasters
Tay bridge1. Wind forces
2. inspection problems The fall of the bridge was occasioned by
the insufficiency of the cross bracing and its fastenings to sustain the force of the gale."
Vector - A force or influence.
Engineering Disasters
Sunshine Skyway Bridge Collapse Poor Planning: Traffic on Tampa Bay Should be designed withstand the potential
of a collision with a vessel.
Engineering Disasters
South Fork Dam Collapse: Poor Planning: The water exceeded the
level of the dam. Once the water level rose to that height, it cut through the earthen dam like a knife.
Saturated the material. Water permeated the material.
Engineering Disasters
Arroyo Pasajero Bridge Scour ; to carry away or remove, as by
a current of water; -- often with off or away
Footings need to go to the bedrock. Bedrock: solid un-weathered rock lying
beneath surface deposits of soil