Millennium Tower (Filene's) | 426 Washington Street | Downtown

[stellarfun]

There were higher priority uses for steel than for buildings during WWII.

 

[whighlander]

There were higher priority uses for steel than for buildings during WWII.

Stel -- Yes -- that's one of the reasons that MIT's legendary Bldg. 20 was built of wood timbers suitable for wharfs -- availability in a Wartime materials shortage

However, I think that another reason both during WWII and also at other times when the schedule for construction was tight -- such as the MIT move to Cambridge --- was that by building with concrete you could pour and move on and up with the rest of the work occurring just below or beside the location where the forms were located and indeed if necessary you could begin to occupy the lower floors while the upper floors were being poured, etc.

I think thanks to some of our more junior members posts that we've already established a lot of the construction related benefits to concrete construction

The point of my last post was to discuss the question of long-term structural integrity of concrete construction -- speciafically:
1) MIT Cambridge Main Building at 100 years
2) Pentagon at 70 years

both in good structural shape despite innumerable alterations and very heavy use

 

[stellarfun]

They recently completed renovations to the Pentagon. Cost was $675 a sq ft. Cost including using steel framing to support the masonry walls, and Kevlar cloth between the steel framing.

 

[whighlander]

They recently completed renovations to the Pentagon. Cost was $675 a sq ft. Cost including using steel framing to support the masonry walls, and Kevlar cloth between the steel framing.

Stel -- that's part of the plan which began in the late 1990's to make the Pentagon a whole lot stronger to withstand trucks filled with explosive and such

In fact the redo of the sectors were phased in such a way that the 9-11 hit happened to be on the then most recently redone sector with the new reinforced walls, windows and columns -- drastically reduced the death toll of the jet hit for two reasons:

1) still not fully occupied
2) by far the strongest part of the building

from the Washington Post:

After 17 years, Pentagon renovation is complete
By Steve Vogel, Published: June 21, 2011

….After 17 years, the job of renovating the Pentagon is complete. Little remains to be done but the paperwork closing out the $4.5 billion program, which when it began was the world’s largest reconstruction project……

Constructing the building took just 17 frenetic months during World War II and remains one of the great engineering feats in U.S. history….

Why did the renovation take so long? …..Lee Evey, who oversaw the effort for five of those 17 years — including after the attack on Sept. 11, 2001 — has an answer: “We took the building apart and put it together again, with 20,000 people sitting in it.”

The building had to be stripped down to concrete columns and rebuilt from slab to ceiling, yet still operate as the Defense Department headquarters 24 hours a day, 365 days a year. Constructed for an era of manual typewriters, the Pentagon needed to be entirely reconfigured to meet modern communications and technology demands. The Sept. 11 attack, which occurred during the renovation, highlighted major safety deficiencies….. Workers installed about 177 miles of cable tray to carry wiring through the building….

[the reconstruction process began when]….. in 1993, with the renovation to be done over 14 years to spread out costs and minimize disruption…..Work began on the basement in October 1994, but it did not go well….Evey took over the project in 1997, instituting design-build techniques in which contractors and designers worked as a team rather than rivals. The work was mapped out with the precision of a military campaign, and the building was divided into five chevron-shaped wedges to be renovated one by one.
Once emptied, the wedge would be gutted…. Then the offices were rebuilt to modern standards…..

The first wedge had just been completed in September 2001 when terrorists flew a hijacked American Airlines jet into the Pentagon’s west wall, killing 125 people in the building and 59 passengers and crew members. The plane struck the newly renovated section, which had blast-resistant windows, structural supports and fire sprinklers. These saved lives, as did the fact that many of the destroyed offices were still vacant…..

After the attack, the renovation program began the Phoenix Project, a race to rebuild the destroyed portions of the building within one year. By the first anniversary, employees were back working in the offices where the plane struck…..The renovation expanded to address vulnerabilities exposed by the attack. In the emergency operations center, for example, building workers can close off water valves from computers, safeguards against the conditions that nearly shut down the Pentagon after the attack…..

The remaking of the 6.5 million-square-foot, 29-acre site is considered such a success in industry circles that its “design-build” techniques have influenced other federal projects….The Pentagon has been “built for the next 50 years,” according to a renovation-program slogan, but officials concede that it is hard to project all future IT needs.
The “legacy Pentagon,” as it is now called, is mostly a memory. Apart from the concrete and the limestone facade, very little of the original building remains. At the last minute, officials preserved a 1,600-square-foot section to show visitors the distinctive World War II-era Pentagon decor……

“The program came in ahead of schedule and below cost,” said Ahmed, the renovation director. “With all the mission changes, and two wars going on, we stayed on course.”

 

[Gromit]

They recently completed renovations to the Pentagon. Cost was $675 a sq ft. Cost including using steel framing to support the masonry walls, and Kevlar cloth between the steel framing.

How would the Kevlar be used "between the steel framing"? What extra protection would it provide?

 

[stellarfun]

How would the Kevlar be used "between the steel framing"? What extra protection would it provide?

Try to keep the masonry intact.

 

[DZH22]

From Monday

 

[tmac9wr]

That first shot is a really cool angle

 

[jdrinboston]

Despite the snowstorm, work was going full blast this morning, both in the Burham and the pit. Those workers are gamers!

 

[datadyne007]

Despite the snowstorm, work was going full blast this morning, both in the Burham and the pit. Those workers are gamers!

They work in the pouring rain and heavy snow when it's actually happening too.

 

[Downburst]

Although I'm not usually a fan of randomly placed elements, I quite like the white spandrel features. They're thin enough to remain relatively unobtrusive, and I feel continued smart use of it will bring verticality and elegance to the tower design.

 

[choo]

Despite the snowstorm, work was going full blast this morning, both in the Burham and the pit. Those workers are gamers!

well they're about 5 years behind schedule

No, certainly, it's not an enviable work on a day like today.

 

[mass88]

Doesn't the snow make of mess of everything?

 

[whighlander]

How would the Kevlar be used "between the steel framing"? What extra protection would it provide?

Gromit -- Blast fragmentation -- if you hit a masonry wall with an impulsive blast wave the wall will under go what is called spallation -- the wave in the surface of the wall can't carry away the energy from the point of impact fast enough [limited by the speed of sound in the material] and so the inner surface of the wall fragments and erupts away from the point of impact -- very bad news for any soft things such as humans who are exposed to the wall, window, inside of a tank, etc.

see the wikipedia animation

http://en.wikipedia.org/wiki/File:Spallation.gif

The solution is to put a net of kevlar that acts as a bullet proof vest for the occupants and catches the wayward fragments before they become lethal weapons

Not to digress too much but the biggest risks to people in a HE bomb blast are:
1) the windows -- the glass rapidly shatters and the shards turn into very lethal weapons
2) hard surface walls -- from spallation -- old wooden walls and massive stone structures were much less of a problem than the popular Federal Building mix of steel frame with masonry veneer exterior
3) structural collapse -- a problem also with mining and other low detonation wave velocity explosives
4) fire and poisonous gases

Typically as in the case of the very extensively studied Mauro Building blast in Oklahoma City -- if you survive #1 and #2 you have a good chance of surviving unless the floor above lands on top of you -- thus the GSA plan to retrofit as many Federal Buildings as possible with window films and kevlar fabric in the walls

 

[tobyjug]

I'd add concussion death/injury due to overpressure to your list.

Hardening the structure increases the risk to occupants if there is an internal blast.

 

[whighlander]

I'd add concussion death/injury due to overpressure to your list.

Hardening the structure increases the risk to occupants if there is an internal blast.

Toby a good point -- my list was focused on external explosion a la the Truck Filled with Ammonium Nitrate - Nitromethane explosive

Since the Murrah Bombing the Fed's have been singularly focused on external attacks -- from the wiki

Building security and construction[edit]

In the weeks following the bombing the federal government ordered that all federal buildings in all major cities be surrounded with prefabricated Jersey barriers to prevent similar attacks.

As part of a longer-term plan for United States federal building security most of those temporary barriers have since been replaced with permanent security barriers, which look more attractive and are driven deep into the ground for sturdiness.

Furthermore, all new federal buildings must now be constructed with truck-resistant barriers and with deep setbacks from surrounding streets to minimize their vulnerability to truck bombs.

The total cost of improving security in federal buildings across the country in response to the bombing reached over $600 million.

In June 1995, the GSA issued Vulnerability Assessment of Federal Facilities, also known as The Marshals Report, the findings of which resulted in a thorough evaluation of security at all federal buildings and a system for classifying risks at over 1,300 federal facilities owned or leased by the federal government. Federal sites were divided into five security levels ranging from Level 1 (minimum security needs) to Level 5 (maximum). The Alfred P. Murrah Building was deemed a Level 4 building.

Among the 52 security improvements were physical barriers, closed-circuit television monitoring, site planning and access, hardening of building exteriors to increase blast resistance, glazing systems to reduce flying glass shards and fatalities, and structural engineering design to prevent progressive collapse.

The attack led to engineering improvements allowing buildings to better withstand tremendous forces, improvements which were incorporated into the design of Oklahoma City's new federal building. \

If you want to see a local example of the rethinking -- wait till the spring and checkout the gardens surrounding the entrance to the Federal Reserve Bank -- all those benches and berms are the new version of the Jersey Barriers and Big Flower Pots that littered the streets outside Fed facilities for quite a few years

 

[Gromit]

Although I'm not usually a fan of randomly placed elements, I quite like the white spandrel features. They're thin enough to remain relatively unobtrusive, and I feel continued smart use of it will bring verticality and elegance to the tower design.

Where are the white spandrels? I thought spandrels were the areas under an arch, but don't see any arches in the previous photos of Burnham building. What am I missing?

 

[timsox6]

There are some white strips going up along the windows. Could also be some sort of exterior lighting.

 

[Semass]

I'm really interested to see how they tie in the glass with the stone cladding on the Washington Street corner and with the brick on Hawley. That bit of the former cladding and detail on the top corner could be an awkward transition to the glass. The glass is also bumped out about a foot or so from the the corners. Will they try to recreate some of that stone on the corner? The renders were ambiguous. Anybody know?

 

[Downburst]

Where are the white spandrels? I thought spandrels were the areas under an arch, but don't see any arches in the previous photos of Burnham building. What am I missing?

I done goofed earlier, the white strips are mullions, not spandrels.