Very Boring is the name of a proposed new tunneling company. We call Very Boring's technology "Rock Disassembly".
Igneous and metamorphic rock, due to distortions from tectonic activity, is usually cracked. Often, there are three orthogonal sets of joints. Such rock can be viewed as a very tightly packed assemblage of separate pieces. Sedimentary rock, due to its origin, is generally layered. Disassembling rock into large pieces is more energy efficient than grinding it into shards.
So far, most of the improvements in tunneling have been incremental, but “Rock Disassembly” has the potential to increase progress rates manyfold, even eventually achieving the Elon Musk touted “order of magnitude” increase in advance rate. This would result in a similar “order of magnitude” reduction in cost. And with that, many previously prohibitive or merely imagined tunnel projects would become possible. To interest others in the tunneling future that Very Boring’s technology might provide, we devote a note here to just a few interesting possibilities. (We invite any other enthusiasts to please chime in.)
Traditional Tunneling Applications: Water supply, mining, railroads, highways, drainage, defense.
Roadless Cities: Where cities are situated on rock all the roads and transport could be easily built underground, exclusively for electric vehicles. On the surface, buildings would be connected by walking and bike paths. Heavy and bulky items like pianos or rooftop air conditioners would be delivered at night by slow moving equipment on wide rubber tracks.
Pumped Storage - useful to store intermittent solar and wind energy. In many places around the world there is a high elevation lake and a lower elevation lake in reasonable proximity. Wherever a tunnel could connect them, large energy storage would become possible. A few sites with enormous untapped potential: Salton Sea, Qattara Depression, Dead Sea, and the Big Sur coast. There are countless more.
California Traffic: A few tunneling ideas specific to California: (see individual writeups in References)
Dumbarton Railroad Bridge / East Bay Tunnels
Silicon Valley Transportation Tunnels
Sepulveda Dam / I-405 / Malibu Tunnel
Corona to Irvine Tunnel
The two main methods of tunneling today are drill and blast and tunnel boring machines (TBMs). Drill and blast is cyclic. A lot of time is lost to changing machines at the face. TBMs stay at the face, but their full frontal grinding of the face is not energy efficient and is slow. TBM's are very heavy and cumbersome to mobilize.
Many energy efficient rock breaking technologies have been invented over the years. Among them are the CERAC Breaker, a mechanical drill/split device that was studied extensively by the U.S. Bureau of Mines. Micro blasting involves detonating squibs in water filled drilled holes. Spiral Drill and Blast was studied at MIT through four phases and found promising. Controlled Foam Injection (CFI) is perhaps most promising. The most efficient rock breaking methods drill a hole and pressurize the existing joints inside the rock face, pushing the rock out toward the free face in large pieces. It's a lot more more energy efficient than grinding the rock into gravel.
However, none of these technologies have reached widespread commercial usage. This can be understood by visualizing a tractor parked in front of a tunnel face employing any one specific tool. It's too slow. That single efficient process must be multiplied. For fast progress, there is a need for many tools working in concert.
A single tension inducing device ranging over a tunnel face is slow and expensive. The rock breaking action might be wonderfully energy efficient. But overall advancement of the tunnel might still be agonizingly slow. As such, there is a need in the industry for a Rock Disassembly framework system. This would permit many tools to be operated in parallel so that they could work in concert to disassemble a rock structure with enhanced efficiency.
Today’s full face tunnel boring machines slowly grind the rock into small pieces. Our proposed Rock Disassembly tunneling system is based on an array of armored robotic arms using tools that continually break out big pieces of rock by pushing outward from behind the advancing face. Many new and novel tools could be interchanged. AI would guide each arm's movement and coordinate with adjacent arms.
Sensors would continually observe the changing rock structure and AI would continuously control the tool array to optimize the rock removal process. Large chunks of rock would be broken out from the center and smaller pieces around the periphery. AI would coordinate the entire tool array, and supervise the overall tunneling system.
A round tunnel shield is diagramically depicted here with tool slots. The complete shield is composed of ten dimensionally identical segments. They are very heavily bolted together. Nine sections have each one large tool slot and two smaller tool slots. The tenth segment at the bottom holds a chain conveyor and a few raker arms.
For easy trucking we can limit the width of each shield segment to 7.8 feet. Then our ten segment shield would be 24 feet in diameter. That could be one of our standard sizes. Different numbers of segments would produce a variety of "standard sizes". The same sections could be bolted into, say, 8 sections (19 feet diameter) up to, say, 15 sections (37 feet diameter). Solid steel wedges between segments would fill the angularities and make everything bolted tight. It's all modular and therefore easily assembled onsite, disassembled afterwards, trucked to the next job, and reassembled into any new configuration.
For many projects a horseshoe shaped shield is preferred. as illustrated below. That shape of tunnel simplifies a two track mucking system. We see the same basic rock disassembly segments with the same tools separated by steel wedges 54a. To derive the horseshoe shape we add two modified segments 54c and two each of wedges 54b and 54d.
The tools that mount in the tool slots could be any of the many rock breaking tools already proven or the unlimited number yet to be invented. The Rock Disassembly system is an experimental test bed. Tools could be changed on the go to adapt to changes in the geology, as required for maintenance, or just to try something new.
The entire operation would exist within an information dense environment. The trajectory of every chunk of falling rock would be charted. Big chunks would be held back until it's clear below. A moveable shelf or special catchers could protect the arms working the bottom half.
To get the picture, imagine 40 experienced miners with powerful and efficient tools constantly talking and watching out for each other, all at, say, 10 times normal human speed. For starters.
A possible idea for an armored Rock Disassembly Arm is pictured. It's has high pressure hydraulics and spherical steel joints in a heavy steel shell. These tools are operating in a avalanche of falling rock. Picture them wrapped in tires or designed protective cushioning. And all the hydraulics with specially designed pressure reliefs to dissipate impacts.