March 2017

SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.

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Page 35 of 51

FIELD SCIENCE 36 SportsTurf | March 2017 needed throughout the project. For starters, we lowered the in- field by 4 inches and made the warning track the same elevation around the entire field. We used software, which automatically adjusts all elevations to create smooth contours and transitions from the infield to all points around the warning track. We then loaded this data into a handheld unit we used to check field elevations and locations. This was essential during demolition to make sure we took out enough material to accommodate the new pea gravel and rootzone depths. We used the handheld unit to verify the exact location and depth of the drain lines and irrigation as they were repaired or installed. The Total Station Unit is also used for all grading, paired with the grading tractor's on-board computer to control the box blade. So regardless of where the grading tractor is on the field, it knows both its own precise location, as well as the elevation it should be at. While a laser box is 2-D, knowing which elevation to be at (but not so much where it is on the field), the 3-D box can go anywhere on the field and always be at the designed eleva- tion. Therefore, the 3-D box grades the finish surface perfectly, reflecting both the subgrade and gravel layer. In fact, for future renovations or field repairs after events, the file can simply be loaded into a grading tractor to restore any point on the field to Continued from page 12 its designed elevation. The finished surface is as smooth and transition free as you can get. Having taken images of the field with the GPR to show us what was beneath the surface, we removed the field without disturbing any more of the sub-grade than was necessary. We were able to salvage much of the drainage system and make repairs in any areas that weren't working properly. We used a series of excavators and dump carts to remove the field, staying on top of the old field while removing to protect the drainage system and sub-grade. The total station was used to establish sub-grade elevations for excavation. The material was hauled to the parking lot and then loaded on semis to haul off site. The field removal took 5 days, totaling nearly 400 loads of material hauled off site. To get to the correct depth in some areas, we had to remove remaining pieces of the old Busch Stadium using concrete saws and excavators to break up the foundation. Since we were lowering the infield by 4 inches, we harvested and stockpiled the DuraEdge (engineered soil) during demolition. We removed 4 inches of base material, formed the infield, and then added the DuraEdge back to the infield, finishing the surface by working new material into the old. REPAIRING THE DRAINAGE SYSTEM Overall, the drainage system was in good condition. Areas the GPR detected that had potential drain line problems did need repair. Settled lines needed to be raised, some lines needed to re- moved and reinstalled to create positive flow to the collectors, etc. After repairs, we re-introduced water to the lines to ensure ev- erything worked and flowed properly. The stadium has a SubAir system that is currently nonfunctioning; therefore we checked all connections and repaired lines to facilitate future use of the system. We used the Total Station Rover to verify and document all lines and repairs. When we removed the old field, one of the first things we did was uncover the zone lines as they come out of the stadium and onto the field. Based on what we uncovered, the irrigation system ended up needing a complete upgrade. Busch Stadium has a single valve bank inside the stadium grounds crew shop, from which all the zone lines run to their respective field zones. We discovered all of these lines were 2-inch PVC or smaller. Based on design calculations, these should have been 2.5- to 3-inch lines to allow for adequate flow and adherence to 5 feet-per-second velocities. So, we initiated the irrigation system upgrades, which included: Just goofing around!

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