DESCRIPTION

As part of an effort to consolidate the Food and Drug Administration (FDA) facilities in Montgomery County MD, buildings 71 and 75 were built to provide much-needed government laboratories and offices.

Pursuing LEED Silver Certification

CHALLENGE

Given the high column loads, soil improvement with Geopier® elements emerged as the best overall foundation solution as it allowed the footing sizes to be significantly reduced. The challenge in this LEED project consisted of providing several hundred Geopier elements for each building in line with the contractor’s sequence. Dealing with limited site access also created a situation in which precision and close coordination with the contractor was crucial to a successful installation.

SOLUTION

In addition to the typical Geopier elements, this project also took advantage of uplift Geopier elements to resist seismic and wind loads as well as Geopier elements with cement treated aggregate (CTA) to provide additional rigidity in the improved soil. The ability of Geopier® technology to be adapted to incorporate uplift harnesses and utilize CTA to increase stiffness speaks to the versatility of Geopier technology. Although caving soils were not initially anticipated, caving conditions were encountered at several locations during drilling operations. By modifying the drilling and compaction operations, caving was controlled and production did not suffer as a result.