Date of Report: December 18, 2023
Recent Activities:
The cofferdam sheet piling for Bay 1 has been completed, and the cofferdam at Bay 1 was sealed for dewatering. Bay 1 excavation has started. Dam armoring excavation, filling, and concrete placement is ongoing (currently on the northeast side of the dam).
Electrical demolition has started.
Change orders (approved and pending):
- Approved a change order that increased the uninterrupted power supply (UPS) time from 20 minutes to 4 hours – that supplies power to the hydraulic power unit (HPU). Basically, it was believed that because the HPU (the HPU is necessary for raising and lowering the gates) is so important, 20 minutes of power backup was not enough time, so the UPS was upsized to provide 4 hours of power backup. This change order increased the Contract approximately $7,000.00 and added 0 days.
- Pending: Steel was previously ordered for the gantry crane bridge which will ultimately be installed over the top of the dam to set and remove stop logs. Upon recent field verification, it was discovered the steel that was ordered was too short and needs to be bent in a different configuration. This survey alignment adjustment and associated subsequences are being discussed by Black and Veatch (engineers), GBRA, Sundt, and Seguin Fabricators.
- Pending: During the excavation of Bay 1, more debris and obstructions were discovered. Bay 1 has the original bypass gates that were used when the dam was originally built (circa 1927). Part of the concrete in the original bypass gates is obstructing the placement of the waler system. Black and Veatch, Sundt, Sundt's structural engineers, and GBRA are discussing possible workarounds/solutions.
Schedule:
- Sundt is continuing to evaluate ways to regain time lost from dealing with unanticipated debris discovered upstream of Bay 1.
- Sundt will be continuing to work through the Christmas holidays, but with limited crew(s).
Upcoming:
In the next several weeks, we expect (1) work to secure the waler system (this is the structural support of the sheet piling that is needed when Bay 1 is completely dewatered); (2) continued Bay 1 cofferdam excavation work; (3) installation of soil anchors in the north upstream abutment wall; (4) continued dam armoring - earthwork and concrete placements; and (5) continued electrical demolition work.
Updated Substantial Completion Date: May 14, 2025
Recent Photographs of Construction Activity/Progress —
