Sunday, March 27, 2011


As I mentioned a few posts back, new measurements and subsequent re-evaluation suggested that the beams on the north side of the Quarry Visitor Center were not vertical and were in need of additional strengthening. Well that project is now completed and here are the results.

With the exception of the end beams, each beam along the north wall was reinforced --- eight in all. Surprisingly, of the many photos I have of the QVC and this project, none show much detail of the north wall beams before repairs. So we’ll have to make due with a recent photo which I have photo shopped to remove the corrections. Each vertical I-beam is welded to a long roof beam that slopes strongly to the south. Given the southward pull exerted on the vertical beam by the roof and the movement of the vertical beams over the years, the engineers were concerned about the ability of the vertical beams to resisted deformation.

Thick steel plating was welded to the back side of each beam for its entire height.

Similarly, thick steel plating was welded to the front of each beam for its entire height.

To resist failure at the juncture with the roof beam, a wedge of steel plating was welded onto the front of the vertical beam and the underside of the roof beam. This was further strengthened by addition plates (fins) that were welded edge on, adjacent to the wedge, along the side of both beams. Looking closely one can see where paint has been removed prior to welding. Remember, the old QVC paint has a high lead content and the heat of welding would vaporize the paint, creating a mix hazardous to breath in.

Built in 1958, the steel armature of the original QVC is now nearly 53 years old. Over that time uplift, down drop, and twisting have made the current repairs necessary, especially if the building and steel is to last another half century. A person getting braces at 53 years of age is pretty rare. Less so for steel beams.

However, we can look at this another way. The iron atoms that makes up the bulk of the steel beam were one of the original constituents of the earth. The age of the earth is about 4.54 billion years old, so these iron minerals are at least that old. However, iron, like all elements other than hydrogen, are made in the fusion engines in the cores of stars. The rate of such element formation is understood to the extent that we know that given its age, the Sun has more iron than it could have produced solely through fusion. What this means is that our sun and solar system must have formed from the remnants of a previous star that went supernova. Those supernova remnants contained abundant iron atoms and eventually condensed to form the Sun and its planets. Given that the universe is 13.75 billion years old, the iron in our QVC beams might have passed through several star lifetimes since it was formed. The same is true for the iron and other elements in our bodies --- the “star stuff” of Carl Sagan.

But I digress. It isn’t the age of the iron atoms that present the failure threat in the beams in the QVC. That’s an issue of engineering and those damn expanding Late Jurassic bentonitic mudstones.

Photos: NPS

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