Aircraft Strike Resilient Skyscrapers

[AnandLeo]

Ten years since the attack on twin towers of the World Trade Centre the discourse on aircraft strike resistance of tall buildings has re-emerged. Some new tall buildings claim to be resilient to aircraft strikes. Most tall buildings are resilient to impacts of light aircrafts. A means of embodying resilience to aircraft impact attack of tall buildings seems to be ring fencing the outer perimeter of the building with robust concrete columns that will not allow the aircraft wings laden with fuel to penetrate in to the building. This concept may increase the cost of the building, but it is purpose-built against large aircraft attack, and may have other structural engineering advantages of a tall building. Of course the columns will need to be aesthetically cladded with granite facia or similar. The space between columns can be protected with an aesthetic fabric of steel bracing.

The issues of progressive collapse, improved fireproofing and evacuation of skyscrapers have been addressed since the 9/11 disaster.

[Wizened Variations]

Originally Posted by AnandLeo

Ten years since the attack on twin towers of the World Trade Centre the discourse on aircraft strike resistance of tall buildings has re-emerged. Some new tall buildings claim to be resilient to aircraft strikes. Most tall buildings are resilient to impacts of light aircrafts. A means of embodying resilience to aircraft impact attack of tall buildings seems to be ring fencing the outer perimeter of the building with robust concrete columns that will not allow the aircraft wings laden with fuel to penetrate in to the building. This concept may increase the cost of the building, but it is purpose-built against large aircraft attack, and may have other structural engineering advantages of a tall building. Of course the columns will need to be aesthetically cladded with granite facia or similar. The space between columns can be protected with an aesthetic fabric of steel bracing.

The issues of progressive collapse, improved fireproofing and evacuation of skyscrapers have been addressed since the 9/11 disaster.

If one would not mind thousands of tons of bird droppings, and, scads of suicide prone cable climbers, surround potential buildings with spider webs of steel cable and break up the planes before they could hit a given building.

You might have to have suicide watch, though.

[AnandLeo]

…….tons of bird droppings, and, scads of suicide prone cable climbers, ……

The concerns of bird droppings and tall building climbers can be easily taken care of in the suggested design concept.
However, the robustness has to continue through the floor beams for the effectiveness of the design. All that robustness of the frame, and flexible restraint of the protective steel bracing web add to the cost as acknowledged. While cost effectiveness is an important factor of a skyscraper for commercial viability, bespoke resistance to aircraft attack is not necessarily a top priority of perpetually competing skyscraper developers.
It may be a redundant philosophy, nevertheless redundancy is the name of the game.

[Tom In Chicago]

Is there a point to this thread? I'm not seeing it. . .

. . .

[Erector99]

It is easier to keep the nut jobs out of the cockpits that what you suggest a(and more economical)

[JohnMarko]

If you wanted a truely disaster proof building, it would have to take the shape of the pyramids, and have 20 foot thick walls, or similar such things, which will never happen.

Buildings will NEVER be designed to withstand an airplane crash - it just isn't going to happen - first, it would be quite cost prohibitive.

Next someone will want a bomb-proof building. Ain't gonna happen.

The ONLY solution is to prevent the idiots from flying planes into the buildings in the first place!!!

[Roadcruiser1]

Again the World Trade Center was well built. The building stood after the plane hit it. Again AFTER THE PLANE HIT IT. What brought it down was the fire that came from the results of the plane impact. They stood long enough for people to get out of. It was a pretty sturdy design. It would have held up longer if it had better fire proofing. It should have better emergency routes for escape though which was the major flaw. The truth is you can't design a building that can ever take the impact of the planes that hit the World Trade Center it's just impossible. It's like asking someone to design a car that can drive off a cliff and it would still be okay. It's impossible. Your best option is to give more options to protect the occupants like more staircases that are wider, elevators that work to allow people to flee, safety floors for people to have air and for people to stop for a while before continuing down the stairs, special elevators for the firefighters, and etc. That is all you can do. Just like how you give cars airbags, and seat belts. You can't make a building that would never collapse but you can give them a way to get out, or to be safe.

"But I don't think it is necessary for us to go out and start designing all our buildings for the impact of jet aircraft. It would create buildings that are not so wonderful places to live and work. They should be robust they should be strong oh yes of course, but special circumstances should not be dictating the way we design high rise buildings."-Leslie Robertson (Engineer of the original and new World Trade Center)

[marshall]

Yeah, it was actually lucky that the towers survived the impacts as long as they did. The impact of the planes blew off the shoddy fireproofing from the steel beams, causing the steel beams to be exposed directly to fire. Each floor was quite thin, and the trusses buckled from the heat fairly quickly. No building can be built to completely withstand the 500mph impact of fully loaded jet planes driven in by crazy, suicidal terrorist fanatics. Yeah, the terrorists used fully loaded jet planes for a reason, the potential for explosiveness and more fire. So that was part of their plan...Luckily, as I have stated many more times, there will NEVER be a september 11-type incident again. It simply will not be permitted, and the element of surprise is no longer there, because it has already been used..If there is so much of a whisper of a plane being hijacked it will either taken over by air marshalls or passengers, or shot down. The chances of a truck bomb at ground level is always there, but because of 9/11, the the only thing skyscrapers today have to worry about from the air is if maybe a plane got lost in fog or something, and collided with a skyscraper, like what happened with the Empire State Building in 1945. And that wouldnt cause as much damage because it wouldnt be used as a 500 mph weapon driven by a bunch of reactionary terrorists.

[Rizzo]

Originally Posted by Roadcruiser1

Again the World Trade Center was well built. The building stood after the plane hit it. Again AFTER THE PLANE HIT IT. What brought it down was the fire that came from the results of the plane impact. They stood long enough for people to get out of. It was a pretty sturdy design. It would have held up longer if it had better fire proofing. It should have better emergency routes for escape though which was the major flaw. The truth is you can't design a building that can ever take the impact of the planes that hit the World Trade Center it's just impossible. It's like asking someone to design a car that can drive off a cliff and it would still be okay. It's impossible. Your best option is to give more options to protect the occupants like more staircases that are wider, elevators that work to allow people to flee, safety floors for people to have air and for people to stop for a while before continuing down the stairs, special elevators for the firefighters, and etc. That is all you can do. Just like how you give cars airbags, and seat belts. You can't make a building that would never collapse but you can give them a way to get out, or to be safe.

"But I don't think it is necessary for us to go out and start designing all our buildings for the impact of jet aircraft. It would create buildings that are not so wonderful places to live and work. They should be robust they should be strong oh yes of course, but special circumstances should not be dictating the way we design high rise buildings."-Leslie Robertson (Engineer of the original and new World Trade Center)

It's an issue that doesn't need to be debated. The building was designed for its time. Structurally it was very strong, but it certainly wasn't up to the life safety standards of today. Fire enclosures for cores are far more robust today than they were decades ago. You also have wider stairways and protected standpipes, and even more organized procedures in case of a tragic event.

Where you can't make up in structural invincibility, you make up in life safety to ensure all occupants can leave a building before the worst happens. In fact, if you read up on past highrise fires, you'll find most, or at least all lives could have been saved if proper emergency escape plans were followed or if emergency systems were working properly (sprinklers, p.a., smoke exhaust, unlocked doors, etc.)

[THE BIG APPLE]

Today's life standards meaning buildings built in MCMLXXIII, or our time period. Buildings (no matter the size) like Temple of the Tooth in Sri Lanka built in MDXCV are able to survive attacks no matter the relativity or scale, big or small. Even the Taj Mahal Palace and Tower in Mumbai (while neither hit by a plane) survive. Another building not hit by planes was the Alfred P. Murrah Federal Building. So why not buildings that were LESS than 30 years old. I'd say any building/skyscraper could survive an aircraft carrier crashing into them, even the Pyramids of Giza.

[Roadcruiser1]

Originally Posted by THE BIG APPLE

Today's life standards meaning buildings built in MCMLXXIII, or our time period. Buildings (no matter the size) like Temple of the Tooth in Sri Lanka built in MDXCV are able to survive attacks no matter the relativity or scale, big or small. Even the Taj Mahal Palace and Tower in Mumbai (while neither hit by a plane) survive. Another building not hit by planes was the Alfred P. Murrah Federal Building. So why not buildings that were LESS than 30 years old. I'd say any building/skyscraper could survive an aircraft carrier crashing into them, even the Pyramids of Giza.

Wrong. Most of the older buildings even Stonehenge were built out of stone or stone like materials (concrete, limestone). These things give the buildings extra bulk and make them much heavier. Also none of these buildings except the Empire State Building has been hit by an aircraft and even then the plane that hit the Empire State Building was much smaller than the Boeing 767's that hit the World Trade Center, the plane that hit the Empire State Building also carried less fuel than the planes that hit the World Trade Center. Also the plane that hit the Empire State Building didn't do it on purpose. It was lost in the fog while trying to land. The planes that impact the World Trade Center were hijacked by terrorists who flew the planes at high speeds to turn them into fly missiles to fly them into the Twin Towers. There is no way you can compare them.

[THE BIG APPLE]

Stonehenge isn't a building, it's a monument. Even if the plane had hit the ESB on purpose, the ESB would still be up to this day.

[Rizzo]

Originally Posted by THE BIG APPLE

Today's life standards meaning buildings built in MCMLXXIII, or our time period. Buildings (no matter the size) like Temple of the Tooth in Sri Lanka built in MDXCV are able to survive attacks no matter the relativity or scale, big or small. Even the Taj Mahal Palace and Tower in Mumbai (while neither hit by a plane) survive. Another building not hit by planes was the Alfred P. Murrah Federal Building. So why not buildings that were LESS than 30 years old. I'd say any building/skyscraper could survive an aircraft carrier crashing into them, even the Pyramids of Giza.

These structures are uneconomical and don't suit our modern needs. They are pure monuments. Beautiful, iconic, and durable for honoring past leaders of great importance and lasting a life time.

Today the primary roll of buildings is to serve the needs of their occupants, maximize space, keep the water out, and resist certain disasters. Buildings are designed to save lives, not themselves.

As far as the economical side of things, no one is going to pay billions for a skyscraper with 3' thick walls and poor environmental quality. Nor could they afford the labor to build it. Keep in mind some of the longest lasting monuments in human history were typically constructed under forced labor with very little compensation. Even in recent American history we've relied on low paying immigrant jobs to build the classic New York highrises you see today.

[Roadcruiser1]

Hayward to tell you the truth Big Apple is only saying this out of paranoia, but again even a studying architecture student which includes me, and Leslie Robertson the engineer of the original and new World Trade Center will say this. This is my quote though Leslie's is on my comment above...

"We can't let 9/11 affect the way we design buildings. Buildings are places that should be a place that allows people to live and work while feeling good about that place that they live and work in. If we design all our buildings for bombings and plane strikes they will no longer be friendly to people anymore because it would render skyscrapers as tall bomb shelters. We don't want to build bomb shelters, we want to build and design buildings that would make the occupants of the building happy, and not cause them to be in fear. 9/11 was just a bad once in a life time event (if you count Pearl Harbor). We just can't let fear from these events strike our heart. It would how scared we are. Instead we should rise and say you hit us, but you can't change us. We will become better and stronger than ever and if you hit us we will hit back, because this was how our nation was built, and it will stay that way as long as the US exists"- William M. (Witness of 9/11 and an architect student with a chance of becoming a future architect).

The best design is a safe design that would allow the occupants to get out. Even Leslie Robertson said "Buildings are not important to me. I am always good at buildings, but people are another matter".

[STR]

Originally Posted by Roadcruiser1

...none of these buildings except the Empire State Building has been hit by an aircraft.

Not...entirely...accurate.

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