Situation:
Harvard University purchased the Blackstone Steam Plant from NSTAR in 2003 to ensure the security of the campus’ steam supply. Shortly thereafter, the University initiated a program of plant upgrade work that would further improve steam supply quality and reliability and prepare the campus for projected growth through the year 2020. BOND provided self-performed civil & utility construction services for two efforts at the plant: an upgrade to its boiler foundations and a repair to its utility tunnel.
As part of the Boiler Foundations project, BOND constructed concrete foundations to facilitate the installation of new, dual-fuel boiler equipment that would meet the campus’ demand for steam. The foundations were partially composed of intricate reinforced steel, requiring close attention to detail during installation. Regarded as “urban surgery,” the Utility Tunnel Repair project involved the demolition and rebuilding of a critical section of the Plant’s deep steam tunnel. Over time, the tunnel had corroded and deteriorated; BOND was employed to restore them to safe working order.
Challenges:
- All plant upgrade work completed while the facility was 100% operational
- Utility tunnel repair required the ongoing operation of one of six high pressure steam lines to maintain heat to campus
- Project completed in close proximity to decades-old piping within confined spaces, 15-feet below-grade, under “live” high pressure and high temperature steam piping
- Site located beneath the busy intersection of Memorial Drive and Western Avenue
Solutions:
- Close coordination with Harvard representatives to sequence completion of boiler foundations by scheduling temporary shut-offs at specific units during construction
- Concrete demolition and soil excavation activities accomplished by hand during utility tunnel repair due to sensitivity of live piping
- Utilization of timber and beam underpinning to reconstruct the 40-foot utility walls from the inside-out to minimize disruption
- Development of site-specific safety protocols with Harvard and local police to facilitate vehicular and pedestrian traffic
Results:
- Utility tunnel repair led to stronger connection between the Plant and more than 100 Harvard facilities, providing continuous efficient heating to campus residents and building users
- Boiler foundation upgrades facilitated efficient steam delivery to 85% of Harvard’s campus
- All work safely completed on time and within budget.