Nestling insurance giant RGA’s new 405,000-square-foot complex into a hillside site in Chesterfield, MO took a combination of technical finesse and muscle on the part of Drilling Service. The site contains two five-story office towers, each equal in size and linked by a two-story atrium lobby, plus a parking garage. It took five drill rigs and five months to drill the shafts for the towers and garage. In addition to the drilled shafts, temporary and permanent earth retention measures were necessary for the below-grade garage and the elevated access road running along the north perimeter of the site. Both beam and plate and timber lagging were used on a temporary basis during construction. A permanent retention solution for the garage consisted of double-corrosion-protected cable strand anchors, set in grout and tensioned
