Riverpark Towers

Newport News, VA

Contractor - Metric Constructors
Engineer - Law Engineering

A proposed 17 story office building was underlain by loose silty sand. The geotechnical engineer considered supporting the building on piles, but the cost was much higher than the cost for improving the subsurface soils and using a shallow foundation system. The loose silty sands were densified by dynamic compaction in approximately two weeks using an 8 ton weight dropped from approximately 50 feet. Standard penetration testing and dilatometer testing were used to verify that the improved soils could support the building with settlement being in an acceptable range.

Dynamic cmpaction was performed adjacent to existing structures without vibration damage. In addition, two sides of the Riverpark Towers site were retained by tied-back earth support systems. The excavation retention system was monitored to verify that no wall deflection occurred during the compaction operations.