24PW11 - Addendum No. 1.pdf

This is a Test Drill Log Addendum for the City of Roseburg, Oregon's Grandview Avenue Storm Water Improvements Project (24PW11), documenting subsurface investigation conducted on April 22, 2026. The drilling operations tested eight holes across three locations: four holes along Grandview Avenue, two holes at the intersection of Northeast Winter Street and Brooklyn Avenue, and two holes at Northeast Walker Court. The total drilling footage was 67 feet using 3-inch diameter holes completed by driller Alex Barbosa on equipment number 900-15. Drilling commenced at 7:30 a.m. and concluded at 1:00 p.m., requiring 5.5 hours of operation. Eight bags of bentonite were utilized during the drilling process. The geotechnical investigation revealed varying subsurface conditions, including fill materials, hard grey rock, soft brown rock and mix, older concrete, and clay deposits at different depths across the three survey locations with GPS coordinates documented for each hole.

The drill log results provide critical subsurface information for the storm water infrastructure project that will install approximately 11,000 linear feet of storm water conveyance system, including 12-inch and 6-inch diameter pipes, six 48-inch diameter storm water manholes, four catch basins, and related site restoration work. These geotechnical findings inform contractor bid decisions regarding excavation methods and potential use of Alternate B, which permits horizontal directional drilling from Station 1+23 to Station 3+23 as an alternative to conventional trenching in rock excavation areas. The project timeline extends 60 days with completion required by October 31, 2026, and bids were due June 25, 2026 at 2:00 p.m., with liquidated damages assessed at $500 per day for schedule non-compliance.