Sustainability and Performance at Hampton Roads Bridge Tunnel (HRBT)-PPT Presentation

PPT Presentation

Pdf Summary

The presentation compares traditional and alternative approaches to managing jet-grouting fluids and spoils, using the Hampton Roads Bridge Tunnel (HRBT) project as a case study. Construction and demolition waste is a major cost and environmental concern, while landfill availability and acceptance are declining. The presenters argue that early planning for fluid reuse and waste reduction can reduce costs, delays, and unnecessary disposal.<br /><br />Traditional one-time-use systems commonly rely on earth pits, gravity settling, solidification materials, or vacuum trucks to collect and dispose of spoils. An alternative uses specialized solids-control equipment to separate slurry into reusable water and dry, stackable solids in real time. This approach can reduce trucking, disposal expenses, site traffic, and bottlenecks, but requires appropriate equipment, skilled labor, regular cleaning, and careful evaluation of project duration and setup costs.<br /><br />At the HRBT South Island project, earth pits initially caused production delays, transport and space constraints, and high solidification-material use. A separation plant was introduced to process all jet-grouting spoils, recover water, produce haulable solids, and support full production. The project involved hundreds of 10-foot-diameter columns and eventually operated two rigs around the clock.<br /><br />The change delivered substantial results: the first 10 months using traditional methods produced 200 columns, while the following eight months produced more than 600. Real-time separation enabled peak output of six columns per day, reported as a 500% increase in productivity. More than 18 million gallons of water were sent for treatment and discharged after meeting EPA standards. The system also avoided more than 4,200 dump-truck trips for off-site solids disposal and eliminated vacuum trucks used in the jet-grouting process.<br /><br />The presentation concludes that alternative fluid and waste management can improve project performance and sustainability, particularly where space is limited, disposal is costly, traffic matters, or production delays are unacceptable.

Keywords

jet-grouting

waste management

fluid reuse

solids-control equipment

HRBT project

construction waste reduction

slurry separation

productivity increase

water treatment

landfill disposal