IRT Engineering Issues

Identified Engineering Issues


IRT report identified issues that need to be addressed by Sound Transit as part of the design of East Link.  The mitigations or changes require sign-off from WSDOT and FHWA.  A PDC request was made in Late August 2015 for documentation pertaining to these items, including open ones.  The section below provides a summary fo the issues raised by the IRT, the current status and a link to documentation received to date.  ST did not provide documents for 8.  Based on a status sheet provided, 2 of the 8 are at some point in the review process, 1 is in draft stages and the remaining are open with no status.

Four of the open issues are one and a half years late based on their necessary resolution milestone.


Issue A: OPEN (Milestone 90% Design)
 Track Bridge/Expansion Joint Design and Performance Criteria

Issue B: OPEN (Milestone 60% Design) <- Late!
Operational Restrictions for Combination of Train Loading and One-year Storm Loading from North

Issue C: PENDING FHWA (Milestone 60% Design) <- Late!
Seismic Vulnerability and Seismic Retrofit of Approach Spans and Transition Span

Issue D:  CLOSED
West Approach Tunnel Design Criteria Consistency

Issue E:  CLOSED
Need for Lightning Arrestors on Floating Bridge and Approaches

Issue F: PENDING FHWA (Milestone 60% Design) <- Late!
Sound Transit Adoption of North Link/Airport Link Stray Current Mitigation Design Criteria for Homer M. Hadley Floating Bridge Installation

Issue G: CLOSED
Impact of Stray Current Dispersion in Lake Washington on Environment and Fish

Issue H: PENDING WSDOT and FHWA  (Milestone 60% Design) <- Late!
Stray Current and Cathodic Protection System Interference and  Compatibility

Issue I: CLOSED (Milestone 60% Design)
Analysis to Confirm Torsional Capacity of the Existing Bridge

Issue J: CLOSED
Analysis "North Wind" Storm Effects on Homer M. Hadley Floating Bridge

Issue K: OPEN (Milestone 90% Design)
Criteria Established for Independent Review Team to Evaluate Numerous Issues

Issue L: PENDING FHWA
Operation and Maintenance Coordination Agreement between Sound Transit and Washington State DOT

Issue M: CLOSED (Milestone 90% Design)
Rider Comfort Performance for LRT Track Bridge at Expansion Joints

Issue N: CLOSED (Milestone 60% Design)
Attachment of OCS Supports to Edge of Homer M. Hadley Floating Bridge Deck Cantilevers

Issue O: CLOSED (Milestone 60% Design)
Methods to be Utilized for Locating Rebar and Post Tensioning in Bridge Deck

Issue P: CLOSED
Determining Strength and Electrical Resistance of Existing Concrete

Issue Q: OPEN (Milestone 90% Design)
Modification of Current Bridge Inspection Procedures if LRT Approved

Issue R: CLOSED
Storm water Drainage System Modifications under New LRT Track Bridge at Expansion Joints

Issue S: CLOSED
Median Barrier Relocation Design, Attachment, Maintenance and Drainage

Issue T:  CLOSED
Washington State DOT’s and Sound Transit’s Goal for Life Expectancy of Bridge

Issue U:  OPEN (Milestone 90% Design)
Method for Identifying Stray Current Failure and Response/Repair Plan

Issue V: PENDING WSDOT and FHWA (Milestone 90% Design)
Effect of LRT Installation on Construction Operations Associated With Anchor Cable Replacement

Issue W: OPEN (Milestone 90% Design)
Additional Needs and Changes Required for LRT Installation to meet  "Blue Ribbon Panel" Recommendations .