Causes of Premature Building Failure: From Design Flaws to Construction Mistakes
We know about the Leaning Tower of Pisa, which leans sideways due to an unstable foundation. But there are many less famous buildings and other construction projects that also have serious design flaws:
· In 2013, London’s nicknamed “Walkie Talkie Centre” began melting cars and frying eggs on the sidewalk because the concave shape caused the sun to act as a mirror. The design also increased wind activity, blowing over street signs, trolleys, and unsuspecting pedestrians.
· In 1981, the suspended walkway in Kansas City’s Hyatt Regency collapsed, killing 114 people and injuring an additional 216. The cause: defective steel support rods that could barely support the bridge itself, let alone all those people.
· In 1978, the Willow Island, West Virginia, cooling tower under construction collapsed when the project’s crane failed. All 51 workers on the scaffold fell to their deaths.
· In 1968, Ronan Point, a 22-story tower in the UK, suffered a progressive collapse: a chain reaction in which a small part of a structure fails but transfers its load to the next part of the structure. As the load increases, the entire structure can give way.
· In 1940, the Tacoma Narrows Bridge in Pierce County, Washington, known as “Galloping Gertie,” twisted, swayed, and collapsed just four months after construction was completed, as a result of 42 mph winds.
What can we learn from these and other construction disasters?
Construction failures can be the result of design error, installation mistakes, or material failure. In the above examples, all of these came into play.
Preventive Measures to Minimize Risk and Ensure Safety
Being proactive as an architect, engineer, or builder basically means thinking backward from your finished product and projecting potential problems so they can be eliminated at the design stage:
· Anticipate extremes. The engineers who built the Hyatt’s suspended walkway and Galloping Gertie were not thinking beyond aesthetics. A swaying or suspended bridge can be beautiful, but not if it’s deadly. What is the maximum load the building or feature will need to bear? Will the floor material you’re considering be too slippery for a senior living community? This is where your building standard begins.
· Accommodate forces. Buildings and bridges sway with wind, gravity, and seismic forces. The construction materials used must be able to handle these forces so there will not be a progressive collapse like what transpired in the UK.
· Allow for temperature changes. Materials, like nature, heat and cool over time. Heat makes them expand, cooling causes contraction. If they are adjacent, can your materials handle the heating and cooling without cracking? Rigid materials such as tile require control joints to alleviate expansion.
· Prioritize the envelope. Consider what will happen at each change of material and plane. The building envelope must prevent air, water and heat from moving from one side to the other.
· Avoid wood if possible. Moisture causes 80 percent of building issues due to mold. Wood is particularly sensitive to moisture and can buckle if it gets wet, or crack and gap if it becomes too dry.
· Use common sense. The Tower of Pisa was built in the 12th century, when the construction crew probably didn’t have the tools (or the insight) to know the soft ground could not properly support the structure’s weight. But the Willow Island tower’s concrete had already begun crumbling the previous day. This disaster could have been averted with proper precaution.
Build strong, safe, and wise, with an eye to stability and durability as well as aesthetics. This is the way to prevent premature building failure.