**Updated June 8, 2012 with Step 2 (cut column with excavated area and shoring) picture**
This blog is a little different than our normal updates. It is a little more technical in nature. We thought that with some of the unique aspects of the project and NC State’s strong engineering programs, there was an opportunity to go a little deeper with an update. We hope you enjoy and let us know what you think of these types of posts. Special thanks to our Construction Manager for their assistance with this post.
This week, RodgersRussell Dayeco, the Construction Manager for the Talley project, installed a support beam. This beam, which weighs over six tons, will be used to temporarily support the northeast corner of the existing Talley to facilitate the excavation of the new 1st floor that will eventually house the new Bookstore and main kitchen for University Dining. The below drawing shows the northeast corner of existing Talley and the columns discussed.
If you have been to Talley lately you’ll notice that we’ve chipped the concrete encasement around two of the existing steel columns (top and bottom columns in the drawing above) to facilitate the welding of the temporary column and cantilevered beam per the design. The column will attach to a new concrete footing that is being supported by four micropiles (center column above). Micropiles are made of steel sleeves that are filled with concrete and extend almost 50 feet into the ground. The below sketch shows a different view of the work and step 1, prepping the columns, installing the beam, column, micropiles, pilecap and brace.
Here is a picture of the two end columns prepped and the pile cap in the center.
Here is a picture of the beam, center column with cover plates and brace in place as illustrated in the sketches. The concrete pads in the foreground are for the new temporary exit stairs.
This work will remain in place until excavation of the new basement, installation of new lower foundation and new concrete pier extension is installed in early September. The sketch below shows step 2, excavating around the column and removal of the piles, cap and part of the existing column.This process starts with the horizontal cut of the column.
Here is a picture of the column cut with the excavation and shoring work in place. Fire separation walls have covered the stairs and support beam.
Finally as mentioned above, step 3 involves the installation of the column pedestal and column extension as illustrated in the sketch below.