History Lessons29 August 2017
Historians contend their subject matter’s utility helps us understand ourselves and the societies in which we live. To borrow an idea from civil engineering—we must understand the foundation before we build upon it. Looking beyond the literal interpretations, in the tunnelling industry without history one cannot appreciate the (comparative) ease, comfort and safety of today’s work environment and modern equipment.
Exploring the past features prominently in the industry right now. Both the Tunnelling Association of Canada and the Underground Construction Association in the US have been working on books recalling the history and accomplishments of their respective industries.
Elsewhere money is being sourced and spent to update tunnel infrastructure for varied end uses. In Los Angeles a 100-year-old tunnel is being refurbished to store increased snow runoff and boost the area’s drinking water supply. In Brockville, Ontario, Canada’s first railroad tunnel is wrapping up renovation work to reopen as a recreation and tourism site. Similar projects are underway in central Virginia at the Blue Ridge Tunnel and recently completed further afield in Wales on a disused Victorian railway tunnel. As much as history is a study of human nature, seeking opportunities to learn and appreciate history seems to be human nature as well.
Looking back helps us move forward—whether learning hard consequences from past failures or reaping inspiration for solving challenges faced today. An example of the latter is in the regional report in this issue. To repair a historic section of the Trout Brook Interceptor in Saint Paul, Minnesota, the project team found a solution that preserves as much of its original beauty as fiscally responsible.
Also in this issue we narrow our focus to shotcrete— looking at how the application process, material and equipment are improving and advancing. Alongside this is further discussion of fibre reinforced concrete.
While the advantages are widely publicized, its use in tunnel segments has been limited in the US and Canada. A new ACI report with guidelines should help reduce uncertainty, and the technical paper in this issue discusses design and specification with this guidance in mind.
It is incredibly important to stay abreast of advances and updated recommendations. To best interpret and appreciate the gains the industry is making be sure to also seek out the labours of TAC and UCA in their new books chronicling the trials and tribulations, achievements and innovations that brought the industry to its position today.