In order to reconstruct the bridge for US 1 over Little Gunpowder Falls, 225, 8 3/4”micro piles, with a capacity of 70 tons were needed to support the structure.
Close proximity to protected waterway and access to abutments created difficulties for size and location of drilling equipment. In addition, an abundance nested boulders presented challenges to the drilling process.
CCGI provided a design build solution utilizing micro piling. The system was proven through an extensive test pile program. CCGI used a specialty overburden system to manage the drilling process through the nested boulders. This system allowed CCGI to advance casing to the required embedment into the bedrock below the boulder layer. In order to overcome the tight access conditions CCGI implemented a Cassagrande M6A-1 to drill the test and production piles. CCGI considered many systems for the installation of these piles, but the maneuverability and capability to drill through the nested boulders with the micro pile system held the advantage over any alternative method.