Removing boulders to allow trenching for utilities
AUI’s largest site development project to date, Special Assessment District (SAD) #228 consisted of 72-acres of site work including:
- Over 65,000 CY of rock excavation requiring extensive blasting and rock trenching
- Over 200,000 CY of import fill material
- Over 50,000 TN of base course material
- Over 200,000 SY of superpave asphalt concrete
- Over 90,000 LF of concrete work that included curb and gutter, sidewalks, ADA ramps, and driveways
- Over 12,000 LF of reinforced concrete pipe in various diameters from 18-in to 96-in
- Approximately 38,000 LF of 8-in to 18-in diameter PVC sanitary sewer pipe installation, 2,000 LF of 6-in ductile iron forcemain, and 1,500 LF of 2-in PVC forcemain, plus a lift station
- Over 200 manholes ranging in diameter from 4-ft to 10-ft
- Approximately 42,000 LF of 4-in to 12-in diameter PVC waterline requiring over 30,000 lbs of ductile iron fittings
- Water and sanitary services to approximately 430 individually owned properties
- Over 66,000 LF of dry utility installation to include electrical, communication, and natural gas infrastructure
- Signalization and lighting
- Signage and striping
- Garden walls and landscaping
- Bike trail
The extensive rock removal on the project had numerous challenges. Basalt formations were very diverse and unpredictable; a single formation could contain voids, veins, and cracks which made blasting difficult due to the unpredictable release of pressure. Blasting was required directly above existing residences and both above and adjacent to active arterial roadways. The entire site was adjacent the Petroglyph National Monument, containing federally protected artifacts. We mitigated these challenges by using vibration and air blast monitoring for all rock blasts, utilizing both permanent and roving monitoring stations.
The fixed Owner’s budget with minimal contingency required careful budget management, especially since the entire design was preliminary and had to be constantly modified to meet the intent. We were also required to provide access to over 300 private land owners throughout the project.
Mayor Richard Berry and other dignitaries cut the ribbon on the finished Project