When we see amazing and efficient structures around us but we often forget about some of the biggest failures in construction. We can learn a lot as civil engineers from these failures. Here is a list of Top 5 construction failures made by Civil Engineering Daily.
5) Leaning Tower of Pisa
Tower of Pisa in Italy is one of the best examples of settlement failure. Settlement of Pisa tower started in 1174 AD.
Pisa tower foundations were built on layers of compressible clay overlaying dense sands. These clay layers effect were not accounted for in soil investigation.
Tower was designed to be 185 feet tall having 8 stories. It started to lean when construction reached the third story. Engineers tried to build rest of the stories away from lean, but it made the tower more heavy resulting in increased lean.
No one is sure why it leans, but following theories were made
- Tower leans because of difference in soil compressibility on each side of tower
- Some Geotechnical Engineers say that lowering in water table is the cause
- Tower eccentric stress is responsible for tilting
At one stage Pisa Tower was on the verge of collapse in 1992. A lot of technical and ground work was done to stop lean.
4) Lotus River Side Complex China
Another failure related to Soil. You can see clearly in above picture that body moved as a rigid body which clearly states that structural design engineers and site engineers are not at fault.
This failure was human negligence more than anything else. Excavation was started near the building foundations as depicted in picture below which increased lateral earth pressure in the direction of fall resulting in collapse
3) Tacoma Narrows Bridge
Tacoma Narrows Bridge was a suspension bridge designed in the U.S state of Washington spanned between Tacoma and Kitsap Peninsula.
Construction of the bridge started in 1938 and it was opened for traffic in 1940. Bridge collapsed dramatically on 7th November 1940.
As soon as the deck of the bridge was built, it started moving in the direction of the wind. The motion was observed even before public opening. Many different measures were adopted to mitigate the movement were in vain and it finally collapsed under 64km/hr wind conditions.
2) Teton Dam
Geotechnical Engineers have learnt a lot from Teton Dam Failure especially in the field of slope stability. After this failure regulations were forced on similar projects by US government.
On the morning of 5th June 1976, the worker on dam noticed leakage which they thought was not alarming. Leakage hole grew larger and larger with time and after some time it burst at 11.55 am sending 2,000,000 cubic meters per second of water into Teton river.
Investigation revealed that Soil type used to construct the slope was permeable and caused water to seep through which increased with time.
1 ) Hyatt Regency Walkway Collapse
Hyatt Regency Failure comes in the category of one of the most deadliest structure design failure in US history until attacks on world Trade Center.
In 1981, two walkways at Hyatt Regency hotel located in Kansas city fell on lobby below where dance competition was being held. In this tragedy almost 114 people died and more than 200 were left injured.
Initial Investigation revealed that changes in the design of the walkway restricted the weight distribution to be held by tie rods and support beams. Whole walkway plus the weight of the people proved too much for ties and beams in the end.