Lakeshore East Joint Corridor – Construction Layout & As-Builts

Project Summary

Construction Layout and As-Built Verification for Major Rail Expansion

The Lakeshore East Joint Corridor expansion required IBW Surveyors to serve as the primary geospatial partner throughout the entire construction phase, translating rigorous engineering designs into precise physical reality across a geometrically complex rail infrastructure upgrade. This massive undertaking involved raising the corridor by four feet and widening it to accommodate two additional tracks, requiring the construction of nine T-wall retaining structures and an extensive secant pile wall system within a narrow, active transit corridor. IBW’s role extended far beyond traditional surveying services to encompass comprehensive construction layout ensuring millimeter-level accuracy for all critical infrastructure, followed by advanced as-built verification that validated the successful installation of this vital transit infrastructure against stringent regulatory tolerances required for high-frequency rail service.

Technical Details

Kinematic Track Surveys with Continuous Geometry Validation

The technical execution of this project required IBW to deploy specialized methodologies that bridged traditional construction layout with cutting-edge mobile surveying technology. Our field crews managed the daily precision layout of nine distinct T-wall retaining structures and the secant pile wall system, ensuring strict adherence to the new vertical alignment specifications throughout the corridor raising process. Following civil construction completion, IBW shifted focus to comprehensive as-built verification of the new dual-track system using the Trimble GEDO trolley for kinematic track surveys. Rather than relying on static discrete point measurements that provide limited coverage, the GEDO system enabled our surveyors to capture absolute track geometry parameters—including cant, gauge, and twist—in a continuous data stream as they walked the alignment. This approach provided rigorous validation of the rail installation against the design model, producing a comprehensive “digital twin” of the final track configuration that documented regulatory compliance across the entire corridor length.

Equipment & Technology

Integrated Robotic Layout with GEDO Mobile Track Verification

IBW deployed a specialized technology suite designed to ensure efficiency and accuracy across both construction layout and final verification phases. The precision construction layout operations utilized high-precision Trimble Robotic Total Stations supported by Trimble GNSS Systems, Trimble DiNi Digital Levels, and Trimble SX10 scanning technology to navigate the complex active site conditions and deliver accurate positioning for all infrastructure elements. Aerial documentation was captured using a DJI Matrice 350 RTK equipped with Zenmuse L2 payload for comprehensive site visualization. For the critical rail as-built surveys, IBW deployed the Trimble GEDO CE 2.0 trolley system paired with high-accuracy profilometers, creating an integrated mobile solution that allowed surveyors to continuously collect data points while walking the track alignment. This system combined inertial measurement data with optical survey measurements to produce seamless, high-precision as-built datasets of the final rail geometry. All collected data was processed through AutoCAD Civil 3D, Microsurvey CAD, Trimble Business Centre, MicroSurvey Star*Net, and Trimble GEDO Office software to deliver comprehensive construction documentation and validation.