Anchoring a Floating Sewer
Lake Oswego, OR
This project was voted number one “Project of the Year” by the AGC in 2010. Jensen Drilling Company played a large part in the completion of this project by drilling and installing over 400 anchors in the bottom of the lake to submerge a sewer line. The anchors were installed on 25 foot center for approximately two miles in a sinusoidal pattern. The anchors were installed in approximately 50 feet of water with drilling depth up to 200 feet. The tolerance for placement was 6 inches. Two Longyear BD 102 drills were mounted on a barge with a 150 foot long open middle section allowing for drilling of up to six anchor holes per barge anchoring location. The barge was anchored so that all six anchor locations were drilled in exact position using satellite survey tools.
This project also required the installation of anchors to support and anchor manholes for the sewer collector pipe. Twelve manholes with six anchors each were constructed and anchored.