York County, PA
GTA provided geotechnical engineering services and construction observation and testing services for this 220(±) acre, five building warehouse project situated around a closed limestone quarry in York County, PA. The site is underlain by limestone bedrock on three of the southern lots, and hard, quartzite, phyllite and schist on the northern two lots. The total footprint of the five buildings is approximately 1.6 million square feet.
The previous quarrying operations left significant disturbance on the majority of three lots, including deep aggregate waste fills, wet clay and boulder stockpiles up to 40 feet high and 3,000 feet long, and a 2-acre, 12- to 14-foot-deep quarry wash sediment pond having compressible soils. A preliminary geotechnical engineering report by another firm did not recognize the wash pond, and included recommendations for the complete removal and replacement of the waste fills and aggregate and boulder fills below building areas. GTA was able to value-engineer the foundation solutions, recommending partial removal and replacement of the unsuitable soils, allowing the client to realize significant construction cost savings.
Other challenges on the site included the design and construction of two, 60- to 70-foot-high fill slopes, settlement monitoring of these deep compacted fill masses, several segmental block retaining walls, and cave and sinkhole remediation in the limestone areas.
GTA’s natural resources team provided consultation on re-interpretation of relic wet areas resulting from old quarry operations. GTA re-delineated these previous identified wet areas to non-regulated areas which helped facilitate the plan review and approval process.