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 bridge 1.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