Boston Seaport Parcel P / 400 Summer Street Project Case Study-Video

Video Transcription

Video Summary

Jeff Taylor of Trevi Icos and geotechnical engineer Demetrius describe construction of a 16-story mixed-use development in Boston’s Seaport, built over air rights near the I-90 tunnel. Trevi’s work included temporary and permanent slurry walls, excavation support, and bracing for the main building, a deep elevator pit, and a parking and service area beneath Summer Street.<br /><br />The complex site required removing old tunnel-project tiebacks, working close to the I-90 tunnel, and coordinating changing construction sequences. The team used clamshells and hydromills for excavation, two levels of internal bracing for the main cut, and a hydraulic bracing system for the elevator pit. Design checks used limit-equilibrium and finite-element analyses, including modeling the tunnel’s construction history. Monitoring showed wall and tunnel movements generally aligned with predictions and stayed within project limits. Existing sheet piles were reused for the back-of-house excavation, with micropile lagging added where needed. Despite tight access, congested bracing, and design clashes, the team completed the work successfully.

Keywords

Boston Seaport

mixed-use development

slurry walls

I-90 tunnel

excavation support

geotechnical engineering