Field Comparison of the Axis Vacuum Microtunneling Technology vs. Open Cut Excavation in Glenview, Illinois

Currently, design engineers and owners of utility systems are trying to utilize innovative methods for installing critical grade pipelines more economically, with minimal disruption to surface activities, and in compliance with environmental concerns. A new technology, the AXIS Vacuum Microtunneling (VMT) system, was developed as a trenchless solution for installation of on-grade pipelines. This paper demonstrates the advantages of VMT through the results of a field evaluation of a sewer project in a pristine residential neighborhood in Glenview, Illinois. Three separate installations of 10" (250 mm) diameter PVC pipes at grades of 0.55% in sections of 176 ft (55 m), 278 ft (85 m), and 331 ft (100 m) in soft clay soil conditions were analyzed. The field analysis studied productivity and costs comparing VMT with traditional open-cut in an attempt to quantify the advantages of adopting this trenchless technology. A cost comparison determined a depth of 10 ft (3 m) as being the point at which VMT begins to be more cost-effective compared to traditional open-cut. Productivity averaged 25.89 ft/hr (7.92 m/hr) for the three VMT installations compared to approximately 18 ft/hr (5.5 m/hr) estimated for a similar open-cut option.