As of the last week in July, the athletic center and performing arts center construction site is sporting two deep holes, and plenty of work went on before they were dug.
“Over the past month we have been putting in all the underground infrastructure and that is complete,” said Mike Bassoni, Harker’s facility director. “We have our new storm lines to control storm water, our new sewer lines and many of our electric and low voltage duct banks in the ground. Those are all mapped by GPS. We can dig down to within an inch and find these pipes, the path they’re traveling and the depth they are in the ground. So if we have to find them later or alter them or add to the system, we know exactly where they are.”
Following installation of underground infrastructure, the whole site was carefully graded using GPS-directed graders which allow accuracy in leveling to within 1 inch, Bassoni noted. As soon as the grading was finished for the gym site, excavation began.
The athletic center excavation was started first and, for several days in mid-July, an unending stream of dirt haulers wound through the construction site, each collecting its load of dirt from the Caterpillar hydraulic excavator and hauling it off. The excavator moves about 135 cubic feet of dirt with every shovelful and the trucks haul away 3-5 shovelfuls each, depending on their capacity. About 1,900 truckloads of dirt will leave the construction site in the end.
A great video of the trucks moving through the loading loop is posted, and there are short videos and photos from throughout the month posted on Instagram https://www.instagram.com/harkerschool/ and Facebook https://www.facebook.com/harkerschool/.
The performing arts excavation is still in progress and the resulting huge pile of dirt will be trucked off campus when summer camps wrap up. The athletic center excavation is already having its earthen walls stabilized with a sprayed-on cement compound.
The basements are critical components in both buildings, noted Bassoni. The athletic center basement will be home to the playing courts, bleachers, locker rooms and guest team rooms. The theater basement will be home to the orchestra pit, below-stage storage areas, and dressing and equipment rooms. Both basements will house heating and air conditioning equipment, but the excavations also hold the main performance areas. “In the gymnasium, you’ll be walking into a promenade at the top of the seating which will cascade to the playing floor 14 feet below entry level,” said Bassoni.
“In the theater, again, you’ll walk into the top of the seating on the main floor and the seating will cascade about a dozen feet to the theater floor in front of the stage,” he added. “Also, underneath the stage, you’ll have trapdoors, an orchestra pit, a grand piano storage area with hydraulics to bring that to the grade level, and a very large mechanical system that will provide heating and cooling into the acting space with absolutely no sense of sound.
“Even when the theater goes to complete black you will not be able to hear the mechanical system running during an intermission or a pause in the acting. So, that’s why we’re creating these basement areas: it’s energy efficient because the earth keeps conditioned air much more stable so you are not using a lot of additional energy for heating and cooling,” Bassoni explained.
Energy efficiency runs deep in the double project. “Both buildings are going to achieve LEED Gold certification similar to that that Nichols Hall achieved in 2009,” said Bassoni. “All of the exterior windows are of a very high efficiency level so that they will keep heating and cooling within the building. The gymnasium will have a 140-kilowatt photovoltaic or solar electric system to keep both buildings about 25 percent off the grid.”
But before all that can be implemented, the basements need to be finished and the site arranged for drop-off access.
Now, in late July, concrete stabilization is already being poured for the athletic center. Once the stabilization is complete in the athletic center basement, the underground plumbing and electrical conduits will be installed, said Bassoni. “Finally, the concrete slab that will create the basement floor will be poured,” he said. “That will happen in late September or early October. We’re moving along at a really fast clip, 10-12 hours per day on excavations so the bulk can be finished by the time school starts.”
At this point, the perimeter around the excavations has been smoothed out and tamped down so that construction traffic can get around the site safely, and part of that access will remain in use for parent drop-off when school starts.
The performing arts center excavation will finish up about mid-August, and stabilization of the gym basement will finish up about the same time. The PA basement does not require a stabilization process as the excavation is utilizing a “lay-back process” which greatly reduces shoring of the excavated sidewalls during construction. The foundation cement pours are slated to begin about mid-September. The entire site will be groomed for the opening of classes in the first weeks of August so, although it might be a bit dusty, student drop-off and pickup will be ready for the start of the school year. Watch for our monthly report on construction project and for updates in Facebook, Instagram and Twitter!