Our team identified core locations using the project’s public hearing map and existing site features as a reference. At each cored location, a test with the Kessler Dynamic Cone Penetrometer (DCP) was performed from the bottom of the asphalt to a depth of approximately 2.5 feet below the pavement surface following removal of the asphalt core. The Kessler DCP is used to estimate California Bearing Ratios (CBR’s) within the subgrade material. At the completion of each DCP test, a hand auger was utilized to excavate the subgrade materials from the bottom of the existing asphalt to depths ranging from 2.2 feet to 5.0 feet below the existing asphalt surface, and the cuttings from the hand auger were visually examined to evaluate the type of soil encountered, soil plasticity, moisture condition, organic content, presence of lenses and seams, colors, and apparent geological origin.

To determine selected engineering properties of on-site soils relative to their use for the project, ESP performed laboratory testing, including natural moisture contents, Atterberg limits, and grain size distribution. ESP utilized the data obtained from field and laboratory testing to provide subgrade remediation and pavement design recommendations for the proposed roadway widening and rehabilitation. A total of three pavement options were presented within the report for improvement and/or rehabilitation of the existing subgrade and pavement and for the pavement structure for potential new pavement or pavement overlay. ESP also provided recommendations for pavement drainage, site preparation, and fill material and placement.