DDS ENGINEERING PLLC recently completed drilling and laboratory-testing services for the Owensboro River Wall project in Owensboro, Ky. The River Wall project will consist of extending the shoreline about 45 feet into the Ohio River and expanding the local Smothers Park by more than 2 acres.
DDS ENGINEERING loaded Qore Property Sciences’ Mobile B-51 drill rig on a barge owned and operated by M. Bowling Inc., to drill soil-test borings along the south bank of the Ohio River.
The purpose of the exploration was to obtain and classify soil conditions at locations predetermined by the city of Owensboro for the River Wall project design team. DDS’s assignment was to provide nine soil-test borings to a maximum depth of 40 feet while performing standard penetration testing. Soil samples were obtained during drilling operations and delivered to the laboratory for testing.
Positioning the drill rig on the barge and stabilizing the barge during drilling operations were challenging tasks to overcome. A platform was built off the front end of the barge utilizing a pair of 4-foot-wide, 21-foot-long and 14-inch-thick wooden mats to allow safe drilling operations to be performed off the end of the barge. The mats were placed with about 6 feet of overhang above the Ohio River. Two stacks of 2-by-10s were screwed to the mats to create a working platform for the drill operators, and safety handrails were built around the perimeter of the work area.
To stabilize the drilling barge from the rivers current, a second barge was placed parallel to the riverbank. Once the stabilizing barge was in place, spuds were dropped to the bottom of the riverbed to reduce horizontal movement. The drilling barge was positioned at the boring location and tied perpendicular to the stabilizing barge.
The drilling method used was a mud-rotary technique – a tri-cone bit connected to the bottom of drill stems rotated to advance the boring. A mixture of bentonite and water was circulated in the borehole by pumping the mud down through the drill stem while picking up cuttings and carrying them to the surface. Split-spoon samples were taken while performing the standard penetration test at depths determined in the field. DDS successfully completed the project in 4 days.