Underground

Underground work is Berkeley Engineering's primary focus. We've been involved in the construction of tunnels using a wide array of techniques ranging from some of the most cutting edge technologies to the most tried and true techniques. We've built tunnels using open face shields and tunnel boring machines, drilled and blasted ground in very tight quarters, and have taken spaders in hand and moved the ground with manpower. In all underground work, the ground and project goals dictate the tunneling technique that is best suited, and our experience provides us with the background to tackle some of the most challenging projects.

Tunnel Boring Machines

Modern Tunnel Boring Machines (TBM's) are powerful machines, and when the project conditions are favorable, they can offer tremendous productivity. We drove a 72" diameter machine for the Los Angeles Department of Water and Power through a bouldery sandstone in Granada Hills, CA in 2002.

Drill & Blast

Berkeley Engineering has employed drill and blast when required. This technique allows flexibility in dealing with ground conditions that range from hard rock, to mixed ground and it can be used on tunnels of any length and size. We have done a drill and blast 4' diameter tunnel in hard andesite beneath highway 101 near Laytonville, CA completed in 1991.

Hand Mining

After all of the advancements that we've made through the ages, sometimes the project calls for us to go back and do what miners have done for centuries, move the ground using our hands. Berkeley Engineering has built tunnels where it was determined that this was the most expedient way to get the job done, and other times it is employed along with other techniques. Luckily for us, at least we have advanced to the point of having pneumatic tools.

Tunnel Retrofits

As the infrastructure that has been built throughout California gets older, it begins to show the effects of the forces of nature. Tunnels are no exception and Berkeley Engineering has done many tunnel retrofit projects. Each tunnel is different, some requiring only some strengthening of the lining and others re-mining failed sections of the tunnel and re-supporting the ground. Our experience can help in identifying the most economical and effective way to keep tunnels functioning and safe so they can continue to serve our needs.

Click to see more pictures of underground projects.