End of June 2016, I was able to attend the annually offered Tunnel Short Course at Colorado School of Mines. This course stretches over four days and includes presentations from professional engineers, designers, contractors, and governmental agencies like L.A. Metro or Sound Transit from Seattle, WA in addition to hands-on labs each afternoon.
During the presentations, each aspect of tunneling was talked about - starting with how to choose the right excavation method, over risk management and site investigations, to tunneling in hard rock and in soft ground, with the finish about planning, safety and cost estimation. The hands-on labs in the afternoon were a welcomed break from all day sitting and I was able e.g. to execute an abrasivity test on rock which includes a pin, a small piece of rock which is scraped once for one second with the pin. Then the pin has to be analyzed with a microscope to measure the wear of the pin tip. The measurement can then be taken to compute an abrasivity number which indicates the hardness of the rock - 10 is very hard and 1 is very soft rock.
Other hands-on labs were all about rock cutting tools which you can find in front of tunnel boring machines, or all about shotcrete or soil conditioning for EPB TBMs
(earth pressure balance tunnel boring machines for soft soils).
Overall, this course is great for tunnel fanatics and those who like to be one.
Thanks for "reading in" and until the next time.
Stephie
Here are some impressions from the course and the labs I attended.
(f.l.t.r. Cutter head of a small TBM; Different cutters from "old age" to now; Geology trail - sandstone rock with layering; Presentation about TBMs; Different ground support systems - Shotcrete applied on steel mash, Steel ribs.)
