VE STUDY SOUND TRANSIT

Owner

Sound Transit

Client

VMS Value Management Strategies

Cost

confident

Timeframe

October 2023 — March 2024

Services performed

VMS Inc. conducted various value engineering workshops on behalf of Sound Transit. DSP was the designated subject matter expert for SEM tunneling and was invited to participate in the value engineering workshops for Alaska Junction Station and BLE Interbay & Ballard Stations VE. Services included joint site visits together with Sound Transit, followed by a weeklong workshop addressing and evaluating project constraints and requirements. Finally, the workshop provided technical, feasible alternative design solutions with the aim of reducing project costs.

Description

The Ballard Link Extension project is designed to extend light rail 7.7 miles from downtown Seattle to Ballard, including a new tunnel and 9 new stations. The project is currently in the environmental review phase. The start of service is scheduled for 2039. The West Seattle Link Extension (WSLE) is a 4.1-mile light rail project by Sound Transit that includes a key underground segment between two underground stations, Avalon and Alaska Junction stations. This tunnelled portion addresses challenging topography and reduces impacts on surrounding communities and infrastructure. The alignment, finalized in 2024, was approved for final design in 2025 following a federal Record of Decision. The WSLE forms part of the Sound Transit 3 expansion to improve regional connectivity in the Seattle area.

Geology

Glacial and nonglacial deposits, with layers of till, cohesionless sand / gravel, cohesionless silt / sand and cohesive clay / silt. The project site is in an area of high seismicity. Geologic hazards include landslides, fault rupture, liquefaction and lateral spreading.

Location

Seattle, WA, USA