Project Clos de la Tech Storage Tunnels/Winery

This DTDS contract completed in June of 2012 primarily consisted of excavating and lining three parallel tunnels of the modified horseshoe shape, each approximately 300 feet long. The tunnels ranged from 25feet to 34 feet in diameter. Also included in the contract ere six 9-foot diameter cross passages (each about 40 feet long), an access shaft 25 feet in diameter by 75 feet deep, drilled 4’ diameter ventilation shafts up to 100 feet deep, and a large soil nail wall at the front portal. Excavation techniques included conventional excavator, electric roadheader, excavator mount roadheader, and drill and blast. Ground support consisted primarily of steel sets and lattice girders with fiber reinforced shotcrete lagging and rock bolts. Ground conditions were mixed and ranged soil to fractured rock to fresh basalt. The most difficult ground conditions consisted of 30,000 psi basalt boulders up to 15 feet in diameter in a soil matrix.