Wake Forest, Wake County, North Carolina
GTA provided geotechnical soil laboratory testing, retaining wall design, and construction observation testing and special inspection services associated with the development of an approximately 75-acre property in Wake Forest, Wake County, North Carolina. New construction at the site included approximately 500,000 SF of single-story flex industrial/office construction, associated site retaining walls, roadways, underground site utilities, and stormwater control measures. GTA provided retaining wall design services for a combination of mechanically stabilized earth (MSE) walls and gravity retaining walls to help facilitate grade change at the site. Max wall heights at the site exceeded 35 feet. Based on GTA’s experience with the local geology and site soil conditions and based on the results of the soil laboratory testing performed, GTA designed the MSE and gravity retaining walls for and recommended the site walls utilize the on-site soils for backfill versus select quarry import as recommended by other consultants. This results in significant (hundreds of thousands of dollars) in cost savings for the owner.
During construction, GTA provided construction observation testing and Special Inspection services including earthwork observation, retaining wall construction observation, soil laboratory testing, and soil compaction testing. Due to the significant grade changes at the site, blasting of rock was required to achieve design site grades. During earthwork activities, GTA provided fill recommendations to help the project contractor utilize the rock generated during blasting as structural fill, and for the remediation of global stability concerns associated with the construction of site retaining walls in low lying areas of the site with soft subgrade soils. GTA’s fill recommendations and soft soil remediation recommendations in retaining wall areas resulted in significant cost savings for the owner. Additionally, during building construction at the site GTA provided foundation soil bearing capacity testing for footings, fluid concrete testing, sampling, curing, and compressive strength testing for footings, slabs, and concrete tilt-panels.