Originally Posted by
MPN11
When the gulf coast/FL panhadle is prone to hurricanes one would have thought more robust infrastructure might have been appropriate to protect such expensive assets.
Isn’t hindsight wonderful!
This is an interesting paper from 2001 which lists damage to be expected in a Catastrophic storm (winds greater than 155 mph) which is where Hurricane Michael came in at. Tyndall has been a base for far longer than the current robust building codes have been in place (1941), and although there will be newer buildings, not everything is built to the current code. Slab-sided buildings like hangars are subject to massive forces at those wind speeds, and as you will see below, it is often the case of "for want of a nail.." the building was lost. To build everything to withstand a Cat 4/5 Hurricane would be cost-prohibitive, so like many things in this world, it's a compromise between resilience and cost, taking the gamble that the "big one" won't hit you. The only sure fire way to prevent Hurricane damage is not to have an Air Force Base on or near the coast in a Hurricane region, it's as simple as that. I currently reside not too far from Patrick AFB in Florida, which is a tropical paradise built on the outer bank of sand south of Cocoa Beach between the Atlantic and the rest of Florida. It's been hit by multiple Hurricanes but without any major damage, and a sure sign it's time to evacuate is when the gaggle of C-130's and HH-60's lift off and head North. If that ever gets hit by a Cat 5 there probably won't be an outer bank any more, never mind an Air Base. In the meantime, the planners keep rolling the dice while keeping the evacuation plans up to date.
So it's not really hindsight, it's risk management and gambling in it's most extreme form. Tyndall's account balance just got reset to zero in this case.
Hurricanes and their Effects on Buildings and Structures in the Caribbean
Hurricanes and their Effects on Buildings and Structures in the Caribbean
by Tony Gibbs, Director, CEP
2.2 Catastrophic Failures
2.2.1 Foundations (Photo 1)
The uplift forces from hurricane winds can sometimes pull buildings completely out of the ground. In contrast to designing for gravity loads, the lighter the building the larger (or heavier) the foundation needs to be in hurricane resistant design. Ignoring this precept has led to some dramatic failure of long-span, steel-framed warehouses.
2.2.2 Steel Frames (Photo 2)
A common misconception is that the loss of cladding relieves the loads from building frameworks. There are several circumstances where the opposite is the case and where the wind loads on the structural frame increases substantially with the loss of cladding.Usually the weakness in steel frames is in the connections. Thus economising on minor items (bolts) has led to the overall failure of the major items (columns, beams and rafters).
2.2.3 Masonry Houses (Photo 3)
These are usually regarded as being safe in hurricanes. There are countless examples where the loss of roofs has triggered the total destruction of un-reinforced masonry walls.
2.2.4 Timber Houses (Photo 4)
The key to safe construction of timber houses in the connection details. The inherent vulnerability of light-weight timber houses coupled with poor connections is a dangerous combination which has often led to disaster.
2.2.5 Reinforced Concrete Frames (Photo 5)
The design of reinforced concrete frames is usually controlled by the seismic hazard. In countries where this is not an issue care still needs to be exercised to ensure that the concrete frames can accommodate the wind forces. There have been a few isolated examples where, ignoring this, has led to disaster.
2.2.6 Telecommunication Towers and Masts (Photo 6)
These are almost always consciously-engineered structures. There is no good reason why so many of them fail in hurricanes. The bad reason is usually inadequate procurement procedures. Specialist advice is not often sought in specifying design criteria for suppliers or in checking that specified criteria have been met. The most common destruction of engineered structures in Caribbean hurricanes is in this class of facility.