Mon, 25 Apr 2011|
In this building construction video, Paul Dansbach discusses structural hierarchy and the collapse resistance of different types of floor systems.
Automatically Generated Transcript (may not be 100% accurate)
Well my name is Paul that's back and walking to acquire -- hearings -- minutes. In this section of training minutes we're going to talk about collapse resistant there's a certain four systems we're also going to talk about structural hierarchy. Understanding structural hierarchy will help us identify which structural components are more important than others. In terms of structural hierarchy building columns or some of the most important structural components of the building. This column runs vertically it runs from the forty or foundation. It runs up its support in this case steel -- Steel -- in turn runs horizontally. And supports the -- journalists on the top of the steel -- That's where how. If our column would have bet. It would result in the -- of support for the being. The beam -- also -- Dropping. The floor -- which are supported by the being resulting in a large area of collapse. Additionally. If this column line runs vertically through the building and support subsequent wars and the roof. The walks of a column in a basement level or the lower level of a building. Will result in a vertical collapses sequence. Vertically through the building to the sports above. And to the -- Resulting in not only a large powers -- -- -- -- a collapse on that encompasses. -- floors of the building above the column which is fail. Building now wherein. Is an old supermarket. The portion of the building and we're standing in which constructed in the 1970s. You'll notice. Before Joyce of this building our large dimensional lumber -- -- actually three by twelve floor journalists. Additionally the three -- -- for journalists have been constructed in a manner designed to support -- heavy -- above. The floor joists are twelve inches on center as compared to the normal framing standard of sixteen inches on center. What that does is allows for greater -- what that means for the fire service. Is that there is more meat in the floor joists that translates to a greater -- time. The fact that -- -- -- twelve inches on senator builds redundancy into the forces. In this case we could have -- vocal wise they're real collapse -- damage to several of the -- but because the joists are redundant. One will help take up a load of he's joining -- should they fell another collapse potential in this building is burned through of the more debt. While we see what we look up between the -- is the underside of the plywood. Board that. Vocalize burn through of the board to act creates a collapse potential and an entanglement potential for firefighters. A firefighters -- May -- throat. In -- and trapping the firefighter in that small area of collapse. As you walk through the basement we noticed this column. This column is unique and that is not connected to a beam at the basement level this -- continues vertically through -- war. Up to a beam that supports the -- Therefore. In terms of structural hierarchy. Any collapse of this column any failure of this column will result in an aerial collapse of the roof. In another part of the base -- we discover column. This column supports it would beam -- it would -- which in turn supports two white tent where journalists. -- -- -- -- -- -- -- -- -- -- This part of the -- system differs from the other part of the -- system in that this dimensional lumber is swore -- dimensional lumber used in the other war. Through -- hands verses three bytes well. Another difference is that these four Joyce for space sixteen inches on center as compared to the three by twelve being placed -- -- -- -- -- Obviously. -- system constructed with a three by twelve is designed to carry in much greater -- -- -- condition which may encounter in a commercial building his. He -- alteration to the floor system that has resulted in multiple layers of war. We have the original -- -- hardwood floor that was installed in the building subsequent to the hardwood floor tile floors install. After the tile floors installed another layer of sub -- was added. Another -- -- pile. A small piece of plywood as the finish coat and then two more layers of the multiple layers of warring may help reduce potential for burn through of the floor -- Understanding structural hierarchy. And understanding the construction and collapse potential forces. Is Paramount firefighters -- Thank you for watching this session of violation hearings treating them.