Bill Martin, PE
led operations for FoxFire and MineDevelopment, two of Drill Tech’s wholly-owned tunneling subsidiaries. Mr. Martin’s expertise is supported by decades of experience utilizing SEM, roadheader, and drill/blast techniques for tunnel and shaft excavation. Several of his projects have been in challenging ground conditions of mixed quality, requiring various ground support methods including lattice girders, canopy tubes, rock bolts, steel sets, and shotcrete. Just a few of Mr. Martin’s licensing qualifications include MSHA Instructor, and Cal OSHA Gas Tester and Safety Representative.
Bill's Featured Projects
Caldecott Tunnel 4th Bore (Hwy 24) | Oakland, CA
Project Manager
This project was part of CADOT's development of Caldecott's 4th bore tunnel on Highway 24 that links the East Bay Valleys and Bay Area. Excavation was performed in the most adverse ground conditions of the tunnel, where a mélange of sandstone, siltstone, and fault materials were identified in the first 200'. The SEM drifts were advanced through an incremental two-pass approach that enabled the appropriate excavation through these faulted zones. A total of 1400 LF SEM excavation was performed, with 700 LF occurring in the 54' wide x 35' tall main tunnel and 700 LF of 14' diameter cross passage tunnels—ground support consisted of rock bolts, canopy tubes, lattice girders, and shotcrete. Drill Tech also installed temporary shoring, including secant pile walls and tiebacks, at the portals as the site location historically experienced landslides.
Blue Eagle Load Mine | Rosamond, CA
Project Manager
This project included drill/blast construction of a 625', 12' x 12' horseshoe tunnel driven on a -15% grade in a switchback configuration. It connected to existing water-filled old workings 300' down the decline. Ground support comprised 5' splitset rockbolts with mine mats on 5' centers and the portal was constructed with steel arch sets with plate cover and shotcrete. Doors were built to keep bats from entering during non-work hours. A refuge station was constructed underground as required by MSHA. Longhole drilling was employed to intercept the water for dewatering purposes and for sampling in the area of the ore.
Mission Trails Pipeline Tunnel & Vent Demolition | San Diego, CA
Project Manager
This project for the San Diego County Water Authority included the construction of a 1954' of 10' x 10' inlet tunnel and 2549' of 10' x 10' outlet tunnel. Shotcrete was applied to the portal areas and the inlet shaft collar area. The inlet tunnel is made up of a 1240' drill/blast tunnel, 100' of mixed face tunnel, and 614' of roadheader tunnel. Support for the drill/blast section was comprised of rockbolts and the remainder with steel sets. The outlet tunnel was driven with a roadheader and supported with steel sets. Ground was spray coated with cement based polymer to prevent slaking. Project included the excavation and support for a 150' deep by 13' diameter inlet shaft—supported by ring beams and shotcrete—and elbow area utilizing a Cryderman shaft mucker. The team excavated a 35' deep by 32' long by 20' wide outlet shaft which was then supported with soil nails and shotcrete. Lastly, cellular grout was installed and backfilled in the 92" diameter carrier pipe in both tunnels and shafts, followed by contact grout.
Nob Hill Improvements Project | San Diego, CA
Project included the construction of a 588' of 10' x 10' horseshoe tunnel by drill/blast methods, installation of 96" welded steel water line, and low-density cellular concrete backfill. The team provided surface drilling and blasting for the excavation of the south portal for the General Contractor. Challenging site conditions included residences within 50' of the tunnel centerline.
