Clos De La Tech Storage Tunnels / Winery

Drill Tech was contracted to excavate and line three parallel tunnels in a modified horseshoe shape, each approximately 300 feet long. During excavation, Drill Tech also constructed six cross passages, an access shaft, ventilation shafts, and a large soil nail wall at the front portal. Excavation techniques included a conventional excavator, an electric roadheader, an excavator-mount roadheader, as well as the drill and blast method. Ground conditions ranged from soil to fractured rock to fresh basalt, with the most difficult ground consisting of basalt boulders of 30,000 psi. Despite these conditions, Drill Tech provided ground support through steel sets and lattice girders with fiber-reinforced shotcrete lagging and rock bolts.