Get Full Government Meeting Transcripts, Videos, & Alerts Forever!
Issaquah staff recommends ground-anchor wall and keep center turn lane for Black Nugget Road
Summary
Staff presented three structural wall alternatives and three roadway layouts for the Black Nugget retaining-wall replacement and recommended a ground-anchor (soil-anchor) wall and retaining the center turn lane to preserve safety and traffic flow. Estimated construction costs range from about $6.2 million to $9.7 million depending on option.
The Mobility and Infrastructure Committee on Feb. 11 reviewed conceptual design alternatives for the Black Nugget Road retaining-wall replacement and the roadway immediately adjacent to it and the administration recommended a ground-anchor wall (Option 3) and retaining the center turn lane (roadway Option 1).
Jim Jacoby, Senior Transportation Engineer in Public Works, presented three wall concepts and three roadway cross-section options. The wall alternatives were: (1) a new soldier-pile wall constructed in front of the existing soldier-pile wall, (2) a new soldier-pile wall constructed behind the existing wall (requiring a large berm and likely full road closure for staging), and (3) a ground-anchor/shotcrete-type wall installed in front of the existing wall with smaller surface impact. Jacoby said the project team expects all three approaches to provide long-term structural life and estimated useful life at 50-plus…
Already have an account? Log in
Subscribe to keep reading
Unlock the rest of this article — and every article on Citizen Portal.
- Unlimited articles
- AI-powered breakdowns of topics, speakers, decisions, and budgets
- Instant alerts when your location has a new meeting
- Follow topics and more locations
- 1,000 AI Insights / month, plus AI Chat
