We had solved all of the layout problems on the 3rd floor rooms and the 4th floor was framed right on schedule. But the 5th floor was the starting point for a general slowdown in production. It just so happened that the existing Harrah’s hotel had a rooftop pool on the 3rd floor and you could observe the pool and the guests starting at the 5th floor level of the new construction. Since it was early summer, the pool was filled with guests’ everyday and every worker on the project seemed to find a reason to do something, anything at all (except work), on the north side of the building which overlooked the pool.
It was fall before we were able to get into full production again. And by then we were on the 24th floor. You had to have binoculars to see the pool by then!
A story:
We were on the 8th floor having lunch one day and I was sitting on a toolbox with wheels, when suddenly I felt the toolbox move slightly. And then again. We all looked at each other as we had all felt the movement. I stood up and the motion became stronger. What was it? The whole building was moving! Since we had been sitting close to the outer wall of the existing hotel tower, one of us noticed that the gap between the two buildings was opening and closing, indicating that only the new building was moving. We put a tape measure down and it showed that the floor we were on was moving about 2” and in a slow circular motion. The general superintendent happened by and we asked him about it. He was mystified as well and quickly went down to the office to call the engineering firm. He was soon back and told us that what we were feeling was the motion caused by the concrete pump on the ground floor. The pump itself was bolted down to a large ‘thrust block’ of concrete that was tied to the structural steel column in one corner. Every time the pump sent a surge of concrete up the ‘slick line’, it moved the building. They had been pumping concrete for the 12th floor during our lunch hour and so we hadn’t heard the usual ‘whoosh…pause…whoosh’ of the wet concrete across the steel deck.
Mystery solved. And what was more interesting was the fact that as we got higher in the building, the motion increased, up to 6” at the roof (24th floor). The engineer came out and told us that it was just what he had planned for.
