SSC completes 396-foot long tunnel under Arizona State Route 101

     SSC Underground’s trenchless division recently completed a 396-foot long tunnel under Arizona State Route 101 at West Beardsley Road for the City of Glendale. This is the second major project that SSC has completed under State Route 101 this year. The other project was a 900-foot long Horizontal Directional Drill at the east end of State Route 101 at the Via De Ventura intersection in Scottsdale, AZ.

     The City of Glendale sold a 14-acre property near Union Hills Road and State Route 101 to a developer to build a car dealership. As part of this project, the city was responsible for extending an existing waterline from the west side of the freeway, to the east side of the freeway, without open cutting or impacting traffic. This waterline extension was built to support continued growth in the area.

Watch the project video below. 

     SSC’s Executive Vice President and Senior Estimator, Arvid Veidmark III has over 30 years of hands-on experience designing and constructing underground projects in Arizona soils. Arvid consulted with the general contractor, Achen-Gardner for several months in the preplanning and design phase of this project to help project managers better understand the complexities of the waterline installation. Arvid consults with project owners regularly on trenchless constructability and design methods, to ensure the best possible outcomes, as owners are often unaware of how to complete an underground construction project on their own.

     Arizona Department Of Transportation (ADOT) road and bridge construction specifications require bore lengths extend outside the freeway right-of-way. ADOT specifications also prohibit any open cutting on or around freeway right-of-way’s, to ensure the integrity of the roadway, and avoid impacting traffic flow. Mechanical tunneling was not a good fit for this project, as there would have been no way to open cut the freeway to access the head, if crews encountered any issues underground. After analyzing these key factors and reviewing geo-technical reports, Arvid recommend the hand-tunneling method for this project.

     SSC was contracted as the Construction Manager at Risk (CMAR) for the waterline installation. SSC construction crews were able to effectively hand-tunnel at a rate of approx. 5 – 6 feet per day utilizing jack-hammers. The soil in this area was particularly challenging, as crews encountered changing conditions including cobbles, boulders, and debris. 

     After daylighting through to the reception pit, SSC crews installed the carrier pipe for the water line, grouted around the pipe, and then backfilled the bore pit. SSC crews were extremely efficient and were able to complete the project successfully on schedule. 

SSC looks forward to working on additional projects for the City of Glendale as it continues to grow and develop new infrastructure.

SSC Underground is a registered Class-A General Contractor fully licensed in Arizona, California, and New Mexico.