HWA provided geotechnical and pavement engineering services to evaluate existing pavement layer thicknesses and subsurface soils and groundwater conditions for rehabilitation of the Taxiway A and seven associated taxiways. Scope of work included performing Falling Weight Deflectometer (FWD) testing, performing pavement coring and shallow excavations, logging the drilling of boreholes using sonic drilling techniques, logging the excavation of test pits and performing Pilot Infiltration Testing.

HWA conducted FWD testing and borings along the western 3,850 feet of the taxiway at Fairchild Airport to characterize the subgrade and provide design parameters for reconstruction. HWA determined design subgrade modulus and provided recommendations to increase the stiffness and stability of the subgrade by the addition of lime or Portland cement, or by over-excavation and replacement of soft soils with properly compacted subbase placed over a geosynthetic separator.

HWA completed geotechnical and pavement engineering investigations to evaluate pavement layer thicknesses and subgrade support conditions along the Taxiway A alignment. Investigations consisted of performing pavement coring along Taxiway A. Dynamic Cone Penetrometer (DCP) testing was performed to assess aggregate base and subgrade strength parameters for use in pavement design. Excavations were made through the pavement core holes to assess subgrade soil types and obtain samples for lab testing