"Bradshaw Construction is one of the best tunneling companies I have worked with. The personnel are first in class with safety, tunneling knowledge and problem resolution. Their equipment looks well maintained and clean."
Bradshaw Construction Corporation’s number one core value is the safety of its employees. Therefore, it is our primary goal to provide a safe and healthy working environment.
Bradshaw Construction Corporation owns and operates an expansive fleet of heavy and underground construction equipment. The size of our fleet ensures every project is properly equipped and operating efficiently.
Throughout our years of tunneling, Bradshaw Construction Corporation has worked on many complicated, sophisticated, and cutting edge projects.
Each of those projects led us to find innovative solutions to unique problems. We invite you to take an in-depth look at projects where you will see the problems we encountered and how we solved them.
Click to view all projects...
Hand tunneling is the excavation and installation of fixed conventional tunnel supports at the tunnel heading by tunnel miners. We can literally create practically any size, shape or length tunnel by hand. The method’s adaptability is exceeded only by its flexibility when encountering unexpected conditions such as buried utilities or unknown or difficult soil conditions. And while the hand tunneling method may be hundreds of years old and what we call “Iron Age Tunneling”, the excavation tools, tunnel support materials, and engineering are 21st century state of the art. Hand tunneling can be very effective in soils below the water table when combined with ground stabilization methods such as dewatering, chemical and cement grouting, and/or compressed air tunneling. Hand tunneling is generally the slowest and often the most costly tunneling method, yet it often provides the least risky option to the client when potential unknowns are a factor.
Hand tunneling is typically performed by tunnel miners using pneumatic hand tools to excavate the soils and then installing wood and/or steel supports for tunnels 42” OD or larger. For 96” OD and larger hand tunnels, Bradshaw is the utility industry leader in using the NATM/SEM (sprayed shotcrete) hand tunneling method. Hand tunnels can be square, circular, elliptical, or horseshoe in shape. Spoil removal is conducted by rail car or in larger diameter tunnels, by rubber tired or track loaders. Whether used with simple wood and/or steel tunnel supports or state of the art NATM/SEM (spayed shotcrete supports), hand tunneling continues to have a place in today's tunneling market. Cobbles, boulders, and hard rock are all potentially insurmountable obstacles for modern small diameter tunnel boring machines, but are generally minor impediments to hand tunneling. In fact, hard rock (>200 MPA) is ideal drill and blast hand tunneling conditions, yet extremely difficult to impossible conditions for TBMs below 8' in diameter.
Bradshaw is an industry leader in hand mined utility tunnels. We were founded nearly 50 years ago drilling and blasting 60” rock tunnels in Northern Virginia. We pioneered the use of compressed air tunneling with NATM/SEM in the USA. We have constructed well over twenty thousand feet of custom hand mined tunnels in the Eastern and Midwestern USA. They range in size from 42" wood box tunnels for electric lines in Washington, DC, to 15' horseshoe NATM/SEM with 45 and 78 degree bends in Atlanta, GA, to 84” liner plate tunnels in Houston, TX, and hundreds of places in between. We have the ability to combine state of the art compressed air ground stabilization with any hand tunnel support system with our fleet of air locks and compressor systems. We hold tunnel blasting licenses in numerous states necessary for the specialized drill and blast excavation of rock in tunnels.
To answer these questions and any others about your next project, please contact us.
Equipment • Employees • Links • Site Map
175 West Liberty Road
Eldersburg, Maryland 21784
• Phone: (410) 970-8300
• Fax: (410) 970-8340