Tunnelling industry needs to retain its workmanship skills Monday, 31 July 2017

A Professor of Geotechnics and Underground Constructions since 2006, Robert Galler also juggles a long list of board appointments, consultancies and R&D projects in the European tunnelling industry.

Austria’s 175-plus-year-old University of Leoben, where he holds his professorship, has a deep history in the field, and was the country’s first university to have a chair of tunnelling.

Pre-professorship, Galler spent a decade at Geoconsult, leading its industrial construction division and heading several major projects, including the Cologne - Frankfurt high-speed railway link.

“We [did] the design for some quite difficult tunnel projects,” he recalls. “The most exciting sections were to underpass the BAB A3 (a very important motorway link between Cologne and Frankfurt) with a side wall gallery tunnel construction as well as to build a deep open pit just parallel to an about 30-m high motorway dam construction.

“For both, we had to find special solutions to get approvals for the construction. As I was also the responsible geotechnical engineer, I spent two days of every week for more than one year on the construction site.”

The following large-scale project was tender design for the Semmering Base Tunnel, over 20 km long, which was stopped for political reasons. A new route is currently under construction, and work on the final stage began last year.

“After that I was engaged in the Brenner Northern access tunnel route (about 40 kilometres of tunnels split up into eight different lots) where I was the project leader for the design for several lots,” he recalls.

“After that project I was the project leader for the design of the largest railway tunnel of the world - Brenner Base Tunnel.”

A current effort Galler leads is the Zentrum am Berg (ZaB) facility, scheduled to open next year.

The innovation and training hub is located inside Styria’s Mt Erzberg, on the site of a former underground iron ore mine. The complex features five tunnel shafts and 3 km of tunnels, which will be used for R&D testing on a 1:1 scale, as well as simulating emergency situations and other training situations.

Its material describes it as offering real conditions “under a large variety of topics like geotechnical monitoring, numerical simulation for geotechnics, research on safety and security, testing of equipment for fire detection and fire protection, risk management, thermo and aerodynamic issues, long-term stability and durability of materials or maintenance of underground infrastructures”.

Other focus areas, says Galler (under his chair “about ten” research projects are currently running) are in the RICAS2020 underground compressed air energy storage project and in reclaiming tunnel excavation material for reuse onsite or by industrial users.

The latter area was explored in the 2012 - 2015 DRAGON European Commission (EC)-funded project, for which he was project coordinator.

The project addressed the fact that excavated material is usually dumped in landfill, and there is untapped opportunity to reuse it. It developed a system integrated onto tunnel borers and described as achieving “the automated bypass analysis, online classification and in-stream sorting” of this material.

The steps as described in an EC summary involve excavation by the borer’s cutting wheel, load monitoring characterisation on rock properties, material discharged by belt conveyor, sampling using a hammer sampler, crushing and conveying, microwave moisture analysis and x-ray elemental analysis, photo-optical grain size analysis, then in-stream sorting of the material “based on the online classification results”.

All steps take place completely underground and the recycled material could be used onsite in concrete aggregates, or elsewhere, for example in cement or steel manufacturing.

At the time of writing, the topic for Galler’s keynote has not been chosen by the Australasian Tunnelling Society.

Depending on the eventual selection, he says attendees could expect to learn more about, “Long-term stability of tunnels tests and results, results from testing several about 30 - 40 years old tunnels, the development of resource-efficient and advanced underground technologies, or results from the EU project DRAGON.”

As a last question, create asks the Professor to name a major shift in the industry that he found concerning, and he nominates a loss of skilled workmanship.

“[It] drives the industry in a direction to work with a staff which is not understanding the technology quite well,” he offers.

“This fact drives up the number of accidents but also drives down the quality of the result (the underground structure). As this situation will even get more dramatic in the future, we - the university together with the industry - have to find solutions.”

[Professor Robert Galler is speaking at the 16th Australasian Tunnelling Conference in Sydney from 31 October – 1 November 2017. The conference will explore the theme Challenging Underground Space: Bigger, Better, More. Only held every three years, the Australasian Tunnelling Conference draws together the best designers, contractors, suppliers and key clients under one roof – don’t miss out on this fantastic opportunity.]