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Jiggy-Z

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Everything posted by Jiggy-Z

  1. Tonight's Episode: Jack Be Nimble, Jack be Dead.
  2. OK. Let's fill in some blanks. So in 2018 there was an engineering report that was commissioned by the board/HOA. Report comes out with findings and recommendations in 2019? Then, possible missing step I have not heard about...Report is received by a different structural engineer for actual plans and specifications based on report Plans and specifications issued as construction documents-when______________. Construction documents sent out for bids and proposals-when_______________. Contractor selected-when______________________ Contractor contracted -when__________________ Contractor submittal documents turned in and approved-when______________ Construction-when________________
  3. Seawater, perhaps not. I'm not sure how they deal with that. The pilings or drilled piers would be another interesting discussion. I think they are less likely to corrode given their limited access to oxidation even in the presence of seawater, but again, I am not an engineer, just a dumb concrete guy. I do have CSB on basement water intrusion: On the Austin Convention Center Hilton lowest level of the parking garage-The subterranean water proofing system and walls were installed incorrectly as was the French drain under the parking level. When the water table rose, the sump pump was unable to keep up and the French Drain system backed up. Before we fixed it there was regularly 3' of water in the basement. The solution was to abandon the installed French Drain system and install a new one along with a second sump pit and pump. Then, about 1,200 holes were drilled into the wall and were set with a manifold system, sealed and then piped to the sumps. The walls were then treated with a crystallizing compound that helped but did not eliminate seepage. It was several million $ to fix.
  4. From the article: The rectangular area is still standing. However, the ellipse shaped area in in the area where the video shows the initial collapse. Also, I just read a CNN article that had one of the tenants talking to her husband moments before or during the collapse. Where she said "there was a sinkhole that opened up where the pool was". Clearly the pool is still there so perhaps she meant the pool deck and perhaps what she saw was the pool deck collapsing onto the lower parking areas before the main building started its fall. I believe she was in one of the collapsed sections so no follow up yet from her.
  5. Looks like a double mat at the column, but yeah, no hidden beam rebar up in there.
  6. My first classical guitar was a Cordoba C5, what a piece of shit.
  7. The stripped area looks pretty thick there between the paint (10" or so) . Perhaps they dropped the slab around the column. No need to have a 10" parking deck.
  8. Would Skoal work for such a thing? Asking for a friend.
  9. You're just a regular MacGyver aren't you? The old one, not the new one.
  10. A lot of fawning over a dead deer. I'll see myself out.
  11. You could not pay me to work on that site. the whole thing still looks sketchy as shit.
  12. OK. Whats going on in these pictures?: Before. Look at the parking garage area in the left foreground. The columns appear to be painted or bare concrete washed by the sun. Now look at the same area after the collapse and some demo work: From the preceding two pictures, it appears that there was a parking deck above the white portion of the columns both at the intact building and at the pool deck. In the first picture you can even see where a car fell down to the below deck farther back in the intact building structure. It looks like the parking deck just fell straight down as did the pool deck. So straight down that cars and pool furniture were not mangled. The collapse video does not show this area clearly, but just behind it is where the first section of main building started to collapse. The pool deck area is where there were problems from the engineering report. The collapse of the second main structure might have caused this area to pancake when its debris hit the parking and pool decks as well. Looks like the tenants in the standing structure were dammed lucky that the collapse stopped at just a portion of the upper deck parking/pool deck area. Now look at the whole pool deck area: It seems odd that where the second collapse came down on the pool deck, the deck collapse stops at the edge of the debris field, yet where the building did not come down by the top (passed the still standing umbrellas), the pool deck and parking structure nevertheless collapsed without direct hit.
  13. Had an acquaintance in college drink beer from a (his)Bass topsider. He was out for two weeks after that with some kind of nasty stomach infection. Imagine that. What a dumb ass.
  14. Yes. It has been discussed here with citations of similar overload cases and was my first guess based on overhead video footage not showing some gaping sinkhole. However, based on the preliminary security video footage, it sure does look like the action started at the bottom-so thinking shifted to sinkhole, water table, or some other kind of subsidence. It will be interesting to see what the engineering investigation finds and what kind of issues,if any, were noted prior. We see spans, bridges, walkways, tunnels and buildings under heavy repair or construction have catastrophic failures pretty regularly around the world. I don't recall anything like this that came on without warning and was so sudden and almost precise in its failure. I mean there are plenty of buildings that fall down but most of the time some flaw is noted, evacuations occur, the situation is monitored and it either collapses on its own or is demolished.
  15. A lot to unpack from previous post. So seems like a problem was known. But to answer your question. Unless you live in a seismic area or have a really awesome building owner, then no there would be no general reporting going on. In this case, reporting would likely come from a tenant reporting spalled columns and shifting walls, as the article says.
  16. I amended that position once I saw a second video. I did not see any pancake from the top. Looked like a failure from the bottom. However, the possibility remains that a pancake could have occurred on the opposite side from the video and then looked like a bottom up failure from the video vantage point. Just seems like a bit of a stretch given the video. I mean look at it. The building looks almost intact going down. The lights even stay on for a couple seconds.
  17. On second thought, it sure looks that first collapse did not start at the top and pancake its way down.
  18. It just takes one weak link. From my mundane CSB case files: We built an enormous detention pond in San Antonio with huge concrete walls. In order to have access into the pond for cleaning and future debris removal and servicing, we built and additional triangle/ramp shaped wall parallel to the long side of the exterior pond walls. The earthwork contractor back filled between the walls and we poured a ramp on top of his backfill. Pretty simple. Normally when using select limestone base as back fill, very little work is required to get passing compaction especially when properly moisture conditioned beforehand. We have passed densities without even using a roller on occasion. So months later I was shocked when the ramp paving failed. They tried to pin it on the concrete, but all of our stuff was inspected and tested. Upon further inspection, the base material that was installed was so loose that voids settled leaving a cavity below the paving which eventually failed. Earthwork contractor did not have his stuff tested, and if he had it would have failed. So they had me fix his work and redo my work, for a nominal fee. I made it especially painful for the earthwork contractor since it would have been so easy to do it right the first time.
  19. ...and it might be awhile before all are accounted for. Even if they are accounted for it might be months before they are recovered given the potentially unstable nature of the remaining structure. In the Hard Rock collapse, there was a construction worker who died whose legs could be seen sticking out of the upper structure. An effort was made to put some kind of tarp or plastic around the protruding portions out of some kind of respect for the dead, but wind and rain only wrapped the covering around the legs and further highlighted and offset his body. It was well over a year before they were able to get him out of there. Hard Rock was a unique case since there were historic structures very close by and a couple of tower cranes that had to be control demoed to avoid further damage, plus New Orleans. I would think that this structure could be shored up and demolition could be done fairly quickly after the investigation as long as there is no underlying sinkhole or other geotechnical anomaly.
  20. From the Wiki: The NTSB cited a design flaw as the likely cause of the collapse, noting that a too-thin gusset plate ripped along a line of rivets, and additional weight on the bridge at the time contributed to the catastrophic failure.[6]
  21. Does not appear to be a sinkhole from other video footage, but who knows. Two recent collapses: Minneapolis Bridge over the Mississippi and Hard Rock Cafe in New Orleans had ongoing work at the times of their collapses. The Hard Rock collapse appears to have been partially caused by heavy point loads from a scissor lift and improper reshoring along with a not fully cured concrete placement. i don't remember exactly what happened in Minneapolis, but it was related to ongoing work. Not saying this is the case here, but there was roofing work going on. If materials or equipment were stored that was too much for the roof, it might have caused the pancaking of the first section that fell. Its hard to tell if it started in one section and then spread. The second section appeared to be leaning inward after the first section went down, probably from the undermining of lower columns and deck structure from the initial collapse. Just my initial thoughts. I am not an engineer, but I am a concrete contractor and have done multi story cast in place buildings.
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