BM Contractors Inc. has completed a $6.2-million emergency road repair on US-70, the Globe-Safford highway in Arizona. The Arizona Department of Transportation and the San Carlos Apache Indian Nation contracted the retaining wall and culvert repair project using a statement of qualifications process.
The scope of the project included developing a soil nail retaining wall, creating ingress and egress access roads, developing a traffic control plan to divert highway traffic to a single lane around the 1,200-lineal-foot work zone, and removing existing culverts. The project team also fabricated and slip-lined three new 13-foot-diameter by 90-foot-long culverts through existing and deteriorated 15-foot-diameter culverts and placed 200 cubic yards of annular grout for each culvert.
To anchor the area, DBM crews drilled and installed 415 permanent soil nails ranging from 15 feet to 43 feet long, installed 15,000 square feet of permanent shotcrete and built wing wall ends of 30 feet to 65 feet on both the upstream and downstream walls. To complete the project, DBM reworked and placed excavated earth outside the Salt Creek basin, scarified and replanted the 3-acre work area, and restriped the highway through the work site.
With restricted access between both sides of roadway, the majority of the work was performed from manlifts. This project was also complicated because the work was performed during potential flash flood monsoon season and during record-breaking weather of 100-degree-plus heat.
DBM completed the project on very steep (1.5H:1V) slopes with loose rocks, boulders and cavy soils, and where water had to be transported from a well seven miles away.
Founded in 1949, DBM Contractors Inc. concentrates on specialty geotechnical construction and design/build heavy civil construction, emphasizing drilled foundation support, earth retention, slope stabilization, and ground improvement. DBM is headquartered in Federal Way, Wash., with regional offices in Vista and San Jose, Calif. The company works on projects throughout the western United States, including Hawaii and Alaska.