get the site elevated, so they could lay out the pad for the building; that was the number one priority,” explains Vardy, referring to one of the two largest walls on the property. It extends along Blue Gentian Road and is 1,350 feet long and approximately 30 feet high, stretching from one entrance ramp on the East side of the site to the other entrance ramp on the West side of the site. The wall was designed to take the live load of large semi-trucks and firetrucks. “It’s not that common to have walls that tall,” explains Kowalski. “We had no structural concerns, though, because we were working with good material and in accordance with the Federal Highway Admin- istration’s design methodology for wall design; it results in a resilient and conservative structure.” The largest wall on site was 32 feet high, but not nearly as long as the one along Blue Gentian. It retains the earth and supports the back, northeast corner of the warehouse. There are three different types of Mirafi geogrid in this section (5XT, 8XT, and 10XT), and the grids are 33 feet long where the building gets closest to the wall. “With walls this size, we had two loaders at one point feeding directly to backfill,” explains Vardy. Structures worked with the company moving the dirt, with each com- pany’s foreman coordinating with the other as truckloads of dirt were moved around the site and dumped into the geogrids. “We laid 1,000 sq ft. of blocks a day, so we needed to be in sync,” Vardy says. The process of back-filling and building the wall simultaneously, as well as working around utilities and storm pipes on-site, created complications. “There were manhole structures we had to work around, pipe culverts we had to bridge over, and a lot of utilities—conduits for electrical lights and for the gas station. With the size of the parking lot, many storm utility pipes would need to be placed within the reinforced zone of the retaining walls, as well as the functionality of a new stormwater management pond,” notes Vardy. Once the first large wall was complete, Structures Inc. prioritized building by when the site or utility contractor was finished and ready to support another wall. At times, they had two or three crews working onsite at one time.
To maximize space for curb and parking stalls, a Sleeve-It® SD-1 pre-engineered fence post anchoring solution was used to install the four-foot fence directly behind the wall block, along with a guardrail. Structures began construction of the walls in April of 2019 and Costco opened its new facility on Friday, November 15, just in time for holi- day shopping. “Building on a site like this with cast-in-place retaining walls would have been cost-prohibitive and many developers would not have at- tempted it,” noted Kowalski. “The technology of using these types of walls has become more advanced and Civil Engineers and De- velopers are more aware of what can be done with reinforced soils.” For the plethora of large warehouses and distribution centers being constructed on large sites, Kowalski said even a relatively flat (two percent) grade across a 1,000 square foot site may likely require a 20-foot-tall retaining wall. For future segmental wall projects of this magnitude, both Kowalski and Vardy have the confidence in Diamond Pro HD blocks to bring the project in on time, with durability and aesthetics--even in the most se- vere climates. For more information, visit www.BelgardCommercial. com or call 1-877-Belgard (235-4273). About Belgard ® Belgard, part of Oldcastle APG, offers a complete collection of paver and wall products for plazas, terraces, parking areas, roadways, rooftops and retaining walls. Available in a range of styles, premium Belgard products have been found in the nation’s finest developments and award-winning commercial and retail properties since 1995. Oldcastle APG is part of CRH’s Building Products division. As the largest building materials company in North America, CRH provides a single-source solution for commercial construction projects with a full portfolio that also includes structural masonry, masonry veneers, dry mix products, hardscape jointing sands and sealants, stormwater management systems, concrete infrastructure, architectural glass, lawn & garden products, and composite decking.
18
csengineermag.com
FEBRUARY 2021
Made with FlippingBook Annual report