Tunnels

Southland Holdings is an expert in all forms of trenchless techniques and technologies. Using hard rock and earth pressure balance tunnel boring machines, horizontal directional drilling machines, shield tunneling, Roadheader, NATM, pipe jacking and drill and blast methods, our team has excavated tunnels and shafts in a variety of geotechnical conditions. From the hardest of rock and stone deposits to soft soils and water-saturated formations 200 feet below sea level, there isn’t a tunneling configuration that Southland Holdings hasn’t been able to conquer.

At Southland Holdings, we hold a few important tunneling “firsts”. In 1976, our subsidiary Southland Contracting completed the first segment tunnel in North America at Thunder Bay. We operated the first TBM in Hawaii for the Kaneohe-Kailua Sewer Tunnel. And most recently in 2022, we “holed through” the Mill Creek Drainage Relief Tunnel in Dallas, TX with our TBM nicknamed “Big Tex”. The unique project required a planned in-tunnel TBM diameter change from its original 38.1 feet to a more compact 32 feet. The first-of-its-kind conversion process was undertaken 1.7 miles into the bore and was not done inside a shaft or pre-excavated portal.