In 2019, DA Smith* cored six horizontal holes up to 40 feet deep into the right abutment of the Boundary Dam as part of a major rock slope stabilization project undertaken by the dam owner, Seattle City Light. Drilling was conducted while suspended from ropes below the dam’s Level 6 bridge deck located approximately 110 ft above the Pend Oreille River. DA Smith partnered with Apex Rock Fall Mitigation, LLC, a subsidiary of Drill Tech Drilling & Shoring, Inc., who provided technical rock face climbing support, who provided technical rock face climbing support.
Holes were cored HQ3 and reamed to a final 5.5-inch diameter to accommodate grouted anchors. DA Smith assisted with video inspection of the boreholes for characterizing rock mass structure. DA Smith also tested the rock mass permeability through the anchor zones using an inflatable packer and specially fabricated, suspended low pressure-low flow hydro tester.
* Formerly as Agapito Associates, Inc.
