The Job
This wet well lightweight fill project is located at HRSD’s Nansemond Treatment Plant, in Suffolk, Virginia. As part of an extensive capital improvement project, the Nansemond Treatment Plant is being upgraded to accept increased flows. The additional flow will be coming via the Hampton Roads Sanitation District’s Hampton Roads Crossing (HRX) project.
As part of the upgrades, a large wet well requires abandonment filling. The structure bears on deep foundation piles, and underlying soils are extremely poor. Therefore, the structure requires low density, self-consolidating fill instead of traditional flowable fill.
The Challenge
The Construction Manager At Risk evaluated multiple lightweight fill materials. Geofoam would provide the least additional load, but due to safety concerns from access into the structure, would not be practical. Foamed glass aggregate fell below maximum allowable densities, but would be difficult to place and compact in the tight space. Expanded shale would be too heavy, and very difficult to place and compact.
The Solution
CJGeo worked with the CMAR, along with the geotechnical and structural engineers to design a fill program which would minimize density, maximize safety, and be optimal for cost and schedule.
CJGeo mobilized a 200cy/hour cellular grout plant to the site, and placed 430 cubic yards of 25lb/cuft CJFill-Ultra Lightweight foamed concrete fill. To manage lateral loads on the walls during placement, two ten foot deep lifts brought the fill to finish elevation.
Speak With An Expert
Facing a similar challenge to this wet well lightweight fill project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.
