Duration: 8 days
Rig: CME 550X, CME 55, Tripod
Scope: Installed 3-100' inclinometers behind north seawall along the Tidal Basin. Inclinometers and vibrating wire piezometers installed to measure movement in the wall. In addition, two tripod borings were completed to depths of 40' inside the Memorial to show soil profile.

Being in close proximity to Washington, D.C., Connelly and Associates, Inc. often has the opportunity to work on the grounds of our national monuments and precious places. These sites present a significant challenge for our drill crews, as we must maintain the drill site in immaculate condition during and after the project. In late October and early November of 2006, we were hired by Schnabel Engineering, Inc. to install geotechnical instrumentation and monitoring wells in test boreholes at the Jefferson Memorial in Washington, D.C. The purpose of the investigation was to determine soil and groundwater conditions related to upheaval and movement of the surficial sidewalks, pavement, and seawall along the Tidal Basin.

We supplied a truck-mounted CME 55 and a CME 550 all terrain drilling rig to perform the drilling operation, utilizing hollow stem augers to advance the borings to bedrock. Diamond core drilling by NQ wireline techniques procured rock core samples and provided a stable socket for the inclinometer pipes installed along the seawall. All auger cuttings were captured at the surface by our specially designed catchment tubs and transported by skid loader to a roll-off dumpster. Heavy-mil plastic covered the areas under and around the drilling machines to prevent unwanted spillage into the Tidal Basin. Two borings were also drilled under the memorial building using a motorized cathead and tripod to obtain samples and install a well.

Site control was necessary throughout the project since the memorial remained open for visitors. Our previous experience at other national places of interest, including the U.S. Capitol building, the White House and the Washington Monument, ensured our successful completion of this project without incident and within project deadlines. Our skilled drill crews on this project were: Drillers Danny Bender and Wesley Wolfe, Helpers Daniel Pao, Wes Smith, Travis Beachley, and Marcelino Larios, and Drilling Supervisors Steve DeLosh and Tom Connelly.