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