Robbins current president Lok Home (left) with Robbins former president Dick Robbins (right).

When asked about his most memorable tunneling project, Dick Robbins narrowed it down to two: The Channel Tunnel and the Paris RER Metro. The former company president and CEO from 1958 to 1993 has seen hundreds of tunneling projects in his career, and should know.  The Channel Tunnel, with its hybrid machines capable of operating under 10 bar water pressure, was challenging to say the least.  But the Paris RER Metro in 1964 resulted in a radically unique machine design: “We created the world’s first below-water, pressure bulkhead shielded machine using air pressure. All future slurry and EPB designs had their genesis in this machine,” said Robbins. A sealing system using steel fingers back-supported with foam kept the gap between the machine shield and segments airtight.  Wire brush seals with grease were not developed until later projects (see below).

The central section of the Robbins machine at the Paris RER metro, with the Arc de Triomphe in the background.

These two projects are just a few of the highlights Dick Robbins is set to touch on during his 2013 Sir Alan Muir Wood Lecture, honoring the late tunneling statesman who initiated and served as the first present of the International Tunneling Association (ITA).

The talk, titled “A Tradition of Innovation: The Next Push for Machine Tunneling” will cover everything from the beginnings of mechanized tunneling to the era of modern tunneling when his father James S. Robbins came up with the idea of developing full-face TBMs (see picture below).  Discussion will then move to modern-day marvels like the world’s largest TBM set to bore the Highway 99 Viaduct Replacement tunnel.  Robbins will make the case that a culture of innovation is needed in greater force in order to push for new leaps in design that will accelerate the advancement of the industry.

James S. Robbins (in driver’s seat), Robbins founder, at the launch of the Humber River Sewer TBM in 1956. The machine was the first ever to exclusively use rolling disc cutters.

See the Talk:

ITA-AITES World Tunnel Congress
Geneva, Switzerland
Opening Ceremony & Sir Alan Muir Wood Lecture
Monday June 3
9:00 AM to 10:30 AM

For more information on Robbins’ long history, check out the lecture Dick Robbins and colleagues made when he received the 2009 Benjamin Franklin Medal.

The completed Central Subway line will provide service between the China Town and Mission Bay areas. “The unique challenges of this project include the dense urban environment and curved tunnel alignment.  Use of the TBM will help us to minimize impact to the community, and the design of the TBMs will help us to negotiate curves using active articulation,” said Alessandro Tricamo, Chief Engineer for the Barnard/Impregilo/Healy JV.  Both machines were designed to enable smooth excavation around tight turns down to 140 m (450 ft) in radius.

The two EPBs were additionally engineered with mixed ground cutterheads using knife edge bits and carbide tools to excavate parallel 2.5 km (1.5 mi) tunnels. Shaft-type screw conveyors will aid in excavation through poorly consolidated silt and sand deposits of the Colma formation below the ground water table.

Robbins horizontal belt conveyors will travel behind both machines for efficient muck removal during tunneling.   “We estimated that a continuous conveyor would help us improve the production rate of the TBMs on steep slopes (up to 7%), where a traditional mucking system using a locomotive would have been a challenge,” said Tricamo.

Project owner San Francisco Municipal Transportation Authority (SFMTA) has set a planned launch date for the first machine in mid-June, and for the second machine by the end of August.  The Central Subway is part of the SFMTA’s Third Street Light Rail Transit Project. Phase 1 of the 10.9 km (6.8 mi), two-phase project began revenue service along the Third Street corridor in April 2007, restoring light rail service to a high transit ridership area of San Francisco for the first time in 50 years.

When Phase 2 is complete, the 2.7 km (1.7 mi) Central Subway line will extend light rail service to the Financial District and Chinatown, as well as provide direct connections to BART and Caltrain, two of the Bay Area’s largest regional commuter rail services. The Central Subway is scheduled to open to the public in 2018. It is estimated that the new subway will serve about 65,000 passengers daily by 2030.

Join Robbins at the World Tunnel Congress WTC in Geneva, Switzerland from June 3-5, 2013.  The exhibition will be held at the Centre International de Conferences Geneve (CICG) which is conveniently located by the Geneva airport and near Lake Geneva and the historic Old Town.  Visit stand G12/G13 to meet with Robbins’ president, Lok Home, and our worldwide sales team.  New project videos and interactive iPads will be on display, showcasing the latest tunneling successes around the globe.  To learn more, set up a meeting with a member of our team by sending us an email or by calling +1 (253) 872-4531

Robbins Technical Sessions

Presentations will be given by Robbins’ representatives during the congress, including a keynote lecture and several technical talks. Session times will be posted as they become available.

Sir Alan Muir Wood Lecture:

Dick Robbins, previous Robbins’ President and CEO, will give the keynote lecture on the topic of “A Tradition of Innovation: The Next Push for Machine Tunneling”. Learn about the history of innovation in the TBM industry, new developments, and improvements still to be made.

Oral Presentation:

“Pre-treatment of Ground in Hard Rock TBM Tunneling: Probe Drilling and Pre-Grouting” presented by Sindre Log, Robbins Civil Engineer

Poster Sessions:

“The Future of TBM Tunneling in Hydroelectric Projects” by Pierre-Alain Scherwey, General Manager, Sales and Business Development, Robbins Singapore

“The Next Generation of Large Diameter, Mixed Ground Tunnel Boring Machines” by Detlef Jordan, Sales Manager Europe, Robbins Europe GmbH

“EPB-Specific Cutting Tools for Challenging Mixed Ground Applications” by Aaron Shanahan, Applications Engineer – Cutters

Technical Sessions: Monday, June 24, 2013

Robbins’ representatives will present on the following topics:

•  Trends in the Performance of Metro-Sized EPB TBM’s: A Study of Worldwide EPB Advance Rates
  • Exploring trends in the performance of metro-sized EPB TBMs that influence overall project successes.
    • By Desiree Willis, Public Relations Specialist
    • 9:30 AM Session: Pressure Face TBM Case Histories 1
• Unprecedented EPB Excavation in High Pressure Mixed Ground Conditions: Study of Performance at the Emisor Oriente Wastewater Tunnel
  • The challenges of excavation at the Emisor Oriente Wastewater Tunnel, which is one of the most difficult TBM tunnels in the world today.
    • By Roberto Gonzales and Andrei Olivares, General Manager and Project Manager, Robbins Mexico
    • 10:00 AM Session: Pressure Face TBM Case Histories 1
• Highly Successful Ground Support for High Cover: A Case Study of the West Qinling Rail Tunnels
  • Discussion regarding the Main Beam TBMs that were specially engineered to combat difficult ground conditions at China’s West Qinling Rail Tunnels, along with an analysis of the machines’ world record advance rates and lessons learned.
    • By Brian Khalighi, Vice President-Engineering
    • 10:00 AM Session: Difficult Ground

“This is a day we all look forward to in the tunneling industry…it’s a good feeling when you get through all of the hard work and eventually break through,” said Andy Birch, Robbins Field Service Manager.  He added “I’m very happy for this joint venture, and they seem very happy too.” The breakthrough was attended by dignitaries, contractors and honored guests, with everyone very enthusiastic about the machine’s success.

Many challenges were overcome by the TBM and its continuous conveyor system on the 11 km (6.8 mi) run, including blocky rock, over-break, power outages, extremely high rock temperature and water inflows. Robbins field service has worked closely with the contractor, a joint venture of Shimizu Corporation, Nishimatsu Construction, UEM Builders, and IJM Construction (SNUI).  Despite the variable conditions, the TBM maintained strong advance rates of 475 m (1,560 ft) per month on average. “Advance rates at maximum were over 650 m (2,130 ft) per month, that is 30 m (98 ft) per day advance,” said Mr. Ohashi, Sr. Mechanical & Electrical Engineer for SNUI JV.

Various methods of support were used during boring, the primary being near-zero rebound fiber mortar (sprayed shotcrete). The Pahang Selangor project marks the first time that this innovative method has been used outside of Japan, and it has been very successful so far. Sprayed shotcrete can be applied during excavation directly behind the cutterhead support, which greatly reduces project downtime. The method also boasts the benefits of dust reduction and good bonding.

The two remaining 5.23 m (17.2 ft) machines are currently boring respective 11 km (6.8 mi) runs, and are on schedule to meet inside the tunnel in autumn 2013. Upon completion, the tunnel will transfer 27.6 cubic meters (7,300 gallons) of water per second to a new treatment plant. The drinking water will supply about 7.2 million people for project owner KeTTHA (Malaysian Ministry of Energy, Green Technology, and Water).

For more information on this project, watch a case study video.

The 2.7 km (1.6 mi) long conduit, constructed by contractor Guangdong No. 2 Hydropower Engineering Co., Ltd, required the use of a Robbins Slurry machine to excavate under 6 bars of water pressure in Zhanjiang Bay.   The TBM, supplied and assembled by Robbins with key components and engineering from Mitsubishi Heavy Industries Mechatronics Systems, Ltd. (MHI-MS), was launched in September 2011.  “The cutterhead design, layout of the cutters and injection ports were the most important design factors in completing this tunnel project,” said Qinghua Shi, Chief Project Engineer for the contractor.

The high-powered Robbins machine featured a smooth flow cutterhead to allow for easier removal of stones and boulders while avoiding clogging at the face.  The mixed ground machine utilized interchangeable knife-edge bits that could be switched out for disc cutters in geology that included abrasive sand, gravel, and silt.   The “smooth flow” design approach for mixed face conditions is consistent with the Robbins design for mixed face EPB-type machines.

During tunneling, the Robbins TBM excavated up to 27 m (89 ft) per day, with no interventions needed.  “Throughout the project, I felt there were no significant problems that happened on the machine. I am happy that we could operate the machine properly. There were no   cutters that needed to be changed, even though this was a long tunnel excavation project. The launch and breakthrough also went very smoothly,” said Shi.

Once in operation, the Zhanjiang Bay Sub-Sea Tunnel will source water from the nearby Jianjiang River to the steel plant on Dong Hai Island.  The water supply for the large company of 20,000 employees is part of a plan by the Chinese government to improve the quality and output of steel in Guangdong Province.

The office is based in Brisbane and headed by General Manager Martin Rauer, who has over 13 years of experience in the tunneling industry in both manufacturing and contracting firms.  While sales is the main function of the subsidiary, field service, project management, spare parts services, and other types of support will be added as market share increases. “Customers will benefit from faster response times and more extensive local assistance and communication,” said Harding.

The office will also provide regional support for two new Robbins projects in Australia, both for use in mine development tunnels.  Later in 2013, an 8.0 m (26.2 ft) diameter hybrid EPB will be launched on the Grosvenor Decline Tunnel at the Anglo American Coal Mine.  The 1.0 km (0.6 mi) tunnel, at a grade of 1:6, will require an explosion proof machine design for excavation in mixed ground with possible pockets of methane gas. In early 2014, a 5.83 m (19.1 ft) diameter Robbins Main Beam TBM will excavate the Carrapateena Decline tunnel for the OZ Minerals copper and gold mine in southern Australia.

Within the next five years, the subsidiary aims to further mine development using TBMs, and to increase sales for both hard rock and EPB machines.  Office contact information:

Robbins Asia Pacific Pty Ltd.
Brisbane, Australia
Phone: +61 (0) 447 050509
Email: rauerm@robbinstbm.com

View from the bottom of a deep shaft at the Jollyville Transmission Main.

The Balcones Canyonlands just north of Austin, Texas, USA is a protected wildlife preserve, and it’s not open to the public.  So when the city of Austin opted to build a 10.5 km (6.5 mi) long water line directly below it, there was understandably some concern—but not for humans. The inhabitants of the Canyonlands include some of the state’s most endangered species, from tiny, blind cave spiders to songbirds to the green-speckled Jollyville Plateau Salamander.  And don’t forget the pseudo scorpions.   The Jollyville Transmission Main, a pipeline planned to bring drinking water to the drought-ridden city, was designed deep below protected aquifers in chalk, up to 106 m (350 ft) down in limestone rock.  This made tunneling the only option.  But even so, how could the project avoid impacting such a sensitive environment?

When I visited the site in Autumn 2012, I got my answer. The contractor, Southland/Mole JV, is taking every precaution to mitigate impact, and they’ve been very successful thus far.  An environmental consultant from the city is on the site daily, and routine inspections ensure that the minimally invasive tunnel is not encroaching on the habitat of the endangered animals.

Our guides for the visit, Kent Vest and John Arciszewski of Southland Contracting, took us to the 82 m (270 ft) deep Four Points Shaft first, which has been partially reinforced with liner plates.  Kent and John explained that during excavation, water inflow from the aquifer had been high enough that the city opted to grout behind the liner plates to prevent further dewatering.  Gravel in the annular space between the liner plates and shaft walls would keep any groundwater pathways intact.

As we descended into the unlined tunnel where a 3.25 m (10.7 ft) Robbins Main Beam TBM was averaging 55 m (180 ft) per day, we talked ground support—or the lack thereof.  Three TBMs are being used to excavate portions of the tunnel in competent limestone.  Southland is not permitted to do either pre-excavation drilling or grouting because of the possibility of karst cavities and groundwater pathways—areas where endangered aquatic species might live.  While they plan to install wire mesh and rock bolts if it’s needed, the rock quality has so far been very good with little ground water.  We took a few photos while in this tunnel (see below), and then moved on to the next site.

The Southland crew in the tunnel.

The unlined tunnel.

Our last site visit of the day was the deepest—the 106 m (350 ft) Jollyville shaft next to the similarly named Jollyville Reservoir in a much more urban location.   Once we’d been lowered down the shaft, we found a small, unlined tunnel in competent limestone.  A 3.0 m (9.8 ft), contractor-owned Double Shield TBM was tunneling this reach, after having been refurbished by Robbins in Solon, Ohio.  Similarly, the machine was getting some fast advance rates of 46 m (150 ft) per day on average.

The TBM operator in the small tunnel sits next to the machine conveyor.

What I immediately noticed in this tunnel was the multitude of small, mostly dry karst cavities down the tunnel walls.  These cavities could potentially be home to the blind cave spiders, though none had been found during tunneling and it was likely they wouldn’t live in such small voids.  We noticed, during our ride on the muck train towards the machine, sparks of light emitting from these cavities.  Once we stopped John reached into a cavity and pulled out a handful of quartz crystals.  “These are all over, in all these cavities.  You can take some with you,” he said.  As I am part-pirate (my genealogy traces back to Sir Francis Drake on my mother’s side!), I decided to stuff my pockets with the sparkly crystals (i.e., treasure!).  I had never seen anything like this before, but John explained that the minerals in the perched water in many of the pockets caused the crystals to grow.  Since the pockets were small, they weren’t filled in or isolated and we could pluck quartz crystals to our heart’s content.

Shining a light on the tiny cavities.

Quartz crystals!

On a more serious note, Southland does have a plan of action if large cavities are found or if a groundwater pathway is very open and linked to the aquifer.  In this case, large voids would be isolated and sealed off to protect the habitat within.  If ground water inflows are severe they will install steel liner plates and grout behind them to stop the flow.  But, says Southland, they don’t expect to encounter either of these since the tunnels are so far below the aquifer.  In fact, one reach of the tunnel, already complete at the time of our visit, had encountered almost no groundwater in 1,300 m (4,400 ft) of tunneling.

Once back on the surface, it became clear to me that this well-designed project proved that tunneling, particularly TBM tunneling, could be used safely in even the most sensitive environments.  The foresight, planning, and execution by the designers and contractors was impressive.  The salamanders and pseudo scorpions thank you.

The TBM breakthrough marks the completion of the fourth tunnel for the 4.15 m (13.6 ft) diameter Robbins Main Beam machine, which underwent major refurbishment in 2002.  Robbins carried out the machine’s latest rebuild as well, which included a diameter change from 4.4 to 4.15 m (14.4 to 13.6 ft) as well as new cutterhead structures including muck buckets and grill bars. Back-up refurbishment and design was done by the contractor. “We are proud the TBM refurbishment was managed in such a short time, and the TBM excavated without any technical interruptions,” said Thomas Güggi of Marti Tunnelbau Ltd.

The TBM successfully excavated through 400 m (1,310 ft) of compact rock and 600 m (1,970 ft) of fractured zones with over-break. “The performance went very well. It was hard work, but we had a special back-up to apply 360 degree shotcrete in these sections,” continued Güggi. The design allowed for a 20 cm (8 in) thick wet application using two shotcrete robots for the full length of the tunnel.

With the TBM bore complete, work ramped up in the difficult ground of the conventionally excavated tunnel.   In order to excavate this section, crews created a reinforced crown of jet grout.  Beneath the jet grout umbrella, crews mined meter by meter with a tunnel excavator, applying a lining of steel arches and shotcrete.

The safety gallery runs parallel to Zurich’s Milchbuck Road Tunnel, a heavily used passage that needed to be updated to the country’s modern safety standards.  The safety tunnel, for Swiss federal office ASTRA, includes five cross passages currently under construction.

The contractor-owned Robbins machine was refurbished and redesigned in Cleveland, Ohio and Mt. Pleasant, Pennsylvania facilities following its most recent excavation at New York City’s Second Avenue Subway.

Its latest rebuild was complex, according to Dave Girard, Senior Engineer for J.F. Shea Construction: “We retrofitted a machine built in 1976 with the latest technology–in particular, variable frequency drive motors.” Other new components include the back-loading cutterhead with 19-inch disc cutters and rescue chamber.

Despite the complexities of the redesign, the machine is scheduled to be launched from a deep shaft in early 2013, proceeding towards the Belmont Wastewater Treatment Plant in what is expected to be competent limestone and dolomite rock.  Robbins continuous conveyors, including a horizontal and vertical conveyor, will aid in muck removal on the long drive.

Once complete, the tunnel will be lined with un-reinforced concrete, making the finished diameter 5.5 m (18 ft).  Cleaner water is the ultimate goal of the city’s new Deep Rock Tunnel Connector (DRTC), along with four shorter tunnels that will be added on afterwards.  The DRTC will convey up to 2.1 million m³ (550 million gallons) of combined sewer overflows daily to the Southport Advanced Water Treatment Plant.   By 2025, the network of five tunnels will total over 40 km (25 mi), and will reduce wastewater overflow into the White River, Fall Creek, Pogues Run and Pleasant Run waterways by 95 percent or more.