More feedback from the pros. We took a site visit to get a raw taste of how rebars are worked on site. Additionally, we asked questions about formworks and concrete pouring. It was interesting to see how the site was arranged in an "assembly line" manner, where one area would be stationed as the rebar cutting, bending, and labeling area. Another area would be cage making, which consists of laying out the rebars, tick marking them, and tying them together. The cages are stacked aside until they are ready for the next, and final station, which is at the location of the pour. This "assembly line" optimizes the routine and enables the contractors to pour a floor slab every 2 days.
Last Thursday after work we took the 7 train out to Shea Stadium where Jess and Tim picked us up and took everyone to the Skanska office where we met with two Skanska executives to discuss construction logistics for our project. It turned out to be a really great meeting. Vince and Shelly have been working in engineering and construction for many years, Vince actually has experience building in Vietnam, so their review of the project was a good reality check. Some of the points they made were:
1. It is a lot easier to plan and design here in an air-conditioned office than out in the field.
3. We need to start getting much more organized in our preparation and planning for construction.
In addition to these themes, they provided us with many ideas and suggestions for building using low-tech methods that can be very effective but are no longer used here in the U.S. It sounded like everyone felt the meeting was extremely valuable despite the fact we all got lost on the way back to the 7 train.
We have been doing more research on the Labyrinth Spillway and it appears that this could be the most cost effective solution to the auxiliary spillway issue.
Brent is looking into the hydraulics of this spillway type, Ryan put together this preliminary design and Jessica will be working on estimating the costs of this configuration and the traditional spillway and water gate.
When the Hydro team finished their study we realized the water gate auxiliary spillway would not be large enough to handle a 100 year flood. Our investigation has shown that the previous failures were due to over-topping so having a adequately sized spillway is certainly a critical aspect of the design. However, when we began looking into typical spillway designs we realized the costs could be much larger than what we have available.
Then Ryan found the Labyrinth Spillway. The idea is that the effective length of the spillway is increased by using a series of trapezoidal or triangular walls instead of a straight wall. This will increase the cost of the water gate but we will save the cost of building an entirely different spillway. There are also potential savings on future maintenance. We are still discussing whether or not this option will be used but it is an interesting idea.