Author: Robbins

NAT 2022

Event Name: North American Tunneling Conference (NAT)
Dates: June 19-22, 2022
Location: Philadelphia, Pennsylvania
Booth: 205

Come join us in Philadelphia, Pennsylvania, USA June 19-22 at the North American Tunneling Conference, the premier tunneling event focusing on current projects, challenges, and successes in tunneling. Our team of experts will have brochures, technical papers, spec sheets, and the latest updates on our machines. Visit our booth 205 to learn more about our ongoing and successful tunneling projects, and be sure to check out our insightful technical presentations.

Technical Presentations

Monday June 20
TBM Technology Session
Salon G

2:00 – 2:25 PM
Unprecedented In-Tunnel Diameter Conversion of the Largest Hard Rock TBM in the U.S.
Presented by Evan Brinkerhoff, Robbins Field Service Site Manager

2:50 – 3:15 PM
Hard Rock Tunnel Boring in Challenging Conditions at the Jefferson Barracks Tunnel
Presented by Doug Harding, Robbins Sr. Vice President

3:15 – 3:40 PM
The Next Generation of Mixed Ground Tunnel Boring Machines
Presented by Brad Grothen P.E., Robbins Technical Director

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Robbins Crossover holes through in the Andes

A Robbins 4.6 m (15.1 ft) diameter Crossover machine holed through in the Andes Mountains of Chile in the last quarter of 2021. The XRE TBM bored a 3.3 km (2.1 mi) long tunnel for Chile’s Los Condores Hydroelectric Power Project (HEPP) and project owner Enel.

A dedicated team, including three Robbins Field Service personnel, guided the machine to breakthrough in conditions including tuff, sandstone, breccia, and conglomerate with sections of high-pressure water inflows. Ground cover reached up to 450 m (nearly 1,500 ft) above the tunnel with rock strengths maxing out at 60 MPa UCS. “Robbins Field Service was an important part of the success of the excavation, evaluating continuous improvements in the machine and correcting faults,” said Ricardo Riveros Puratic, Project Engineer for Enel.

For Riveros Puratic, Crossover machines make sense despite the challenging conditions: “Towards the end, [the TBM] exceeded expectations. Crossover TBMs are suitable for Andean geology of sedimentary and volcanic type, where there is a great range of rock strengths and hydrogeological conditions.” Maximum advance rates topped out at 605.8 m (1,988 ft) in one month and 212.8 m (698.2 ft) in one week.

The Crossover machine featured a heavy duty, centrally mounted screw conveyor for the duration of the drive. The TBM remained in a hard rock configuration with muck chute installed, along with paddles, bucket lips, scrapers and disc cutters on the cutterhead. However, “75% of the excavation was performed using the main drive gearboxes in high torque configuration (EPB or low speed mode). We never physically changed the cutterhead or screw conveyor to EPB mode,” said Omar Alvarez, Robbins field service site manager at Los Condores.

High-pressure ground water inflows were the key challenge of the project. “When we started the excavation, we used dewatering hoses to reduce the water into the cutterhead during the excavation,” said Alvarez. Water pressures rose whenever the TBM stopped, however. “During the segment ring installation, we stopped the water from draining through the rear shield drilling ports and we closed the screw conveyor rear gate. We reached 7+ bar in the cutterhead earth sensors.”

“We bored in places with 5,500+ liters (1,500 gal) /min, making back-fill grout injection behind the concrete segments a challenge. We decided not to use the grout injection through the tail shield ports, but instead injected grout directly through the concrete segment with hoses. This approach was more flexible and reduced the need for reinjections,” said Alvarez.

With multiple triumphs and lessons learned during tunneling, Alvarez reflected on the breakthrough: “I’m proud to be part of a team that finished a tunnel in the Andes Mountains.” Once brought online, the Los Condores HEPP, located in the mountainous southern Maule region, will have an annual generating capacity of 150 MW.

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NASTT No-Dig

Event Name: NASTT No-Dig 2022
Dates: April 10-13, 2022
Location: Minneapolis, Minnesota
Booth: 903

Join experienced Robbins staff at the largest trenchless technology conference in the world, NASTT No-Dig in Minneapolis, MN. Find out more about our line of Robbins Small Boring Units (SBUs) —game changers in the trenchless industry, saving you time and money on your next hard rock or mixed ground utility tunnel.

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Tunnel Turkey

Event Name: Tunnel Turkey International Tunnelling Symposium
Dates: December 21-22
Location: Şişli/İstanbul, Turkey
Venue: Fairmont Quasar İstanbul
Booth: Stand 8

Join us December 21^st and 22^nd for the Tunnel Turkey International Tunnelling Symposium in Istanbul. Our team of international experts will be speaking on Robbins’ latest products and projects during the conference, including non-circular innovations for hard rock tunneling. Stop by Robbins’ stand 8 to find out more on our projects in Turkey, including our record-breaking project in Esme! The Esme-Salihli project has bored 32.4 m in a day, 178.2 m in a week, and 721.8 m in a month using Robbins Crossover XRE machine, making it the fastest machine over 13 m in diameter ever recorded.

Robbins Lecture

Non-Circular Tunneling in Rock: A New Way Forward
Presented by Brad Grothen P.E., Robbins Technical Director

Abstract: When a flat roadbed is needed, is a circular TBM the best way to go? In this presentation, Robbins Technical Director Brad Grothen will discuss a mechanical boring machine currently being used in the mining industry for a rectangular tunnel cross section, and the potential for use of this machine in civil tunneling. Grothen will also look at emerging technology to demonstrate that by using non-circular TBMs, a flat invert can be safely and economically created in one pass.

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MDM5000 Brochure

Find out more about Robbins’ innovative solution for underground mining, the MDM5000 (standing for Mine Development Machine with dimensions of 4.5 m x 5.0 m).  The MDM5000 is the world’s first successful rectangular boring machine for hard rock, and creates a flat invert as it bores for road access.

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Reach First Ore Quicker

Deep underground ore bodies require a new approach: Rectangular rock boring machines create access and development drifts with flat inverts that enable immediate use of the tunnel by rubber-tired vehicles. These non-circular tunnel boring machines bore tunnels in rock up to 200 MPa UCS at twice the rate of drill & blast, and with fewer ground support requirements. Find out how to reach your ore body quicker, safer and more cost effectively in this exclusive webinar in conjunction with Mining Magazine.

In this recorded, 60-minute webinar you’ll learn about the successful use of a rectangular rock boring machine at Fresnillo silver mine in Mexico, where the equipment has advanced more than 1,700 meters at rates of up to 191 meters in one month. Listen in as Robbins President Lok Home discusses ongoing developments for underground mining, including ways to directly mine the ore body using tunnel boring machines. The presentation will conclude with a discussion on future developments in underground mining, moderated by Mining Magazine.

WATCH THE RECORDING

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EXPOMIN

Event Name: EXPOMIN
Dates: October 25-29
Location: Santiago, Chile
Venue: Espacio Riesco
Booth: 3-F21, Hall #1

Join Robbins at the most important Mining exhibition in Latin America! EXPOMIN will be hosted in Santiago, Chile from October 25^th to the 29^th. Come learn more about the astonishing work our MDM5000 has been doing at the Fresnillo Mine–the first successful use of a rectangular rock boring machine. Our team of professionals are eager to meet and talk about a solution for your next underground mining project. Check out this map of the exposition hall and look for the Robbins R to find our stand location 3-F21. Stop by to see our latest products and projects!

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Mineria 2021

Event Name: Mineria 2021 International Convention
Dates: October 19-22
Location: Acapulco, Mexico
Venue: Forum Mundo Imperial
Booth: 706-706A

Come join us in Acapulco, Guerrero at the 2021 Mineria International Convention and learn more about Robbins’ latest innovation, the MDM5000. The machine has bored more than 1,700 meters of a mine access tunnel in andesite and shale with quartz intrusions. Stop by the TOPO/Robbins booth 706-706A to see the astonishing work that has been done at Fresnillo mine in Mexico. Meet with Robbins international experts who are ready to discuss a solution for your next underground mining project. 

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Mine Development Machine: Successful Rectangular Rock Bore in Fresnillo, Mexico

A rectangular tunnel boring machine, known as the MDM5000, has successfully bored a hard rock tunnel with flat invert in Fresnillo, Mexico. Watch the video to find out more from Robbins personnel, mine officials, and those operating the new machine on a daily basis.

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Robbins develops Rectangular Rock Mining Machine for Flat Invert

Robbins’ latest innovation is making good headway on a non-circular tunnel excavation in hard rock. The rectangular TBM, known as the MDM5000 (standing for Mine Development Machine with dimensions of 5.0 m x 4.5 m) is capable of excavating a flat tunnel invert for immediate use by rubber-tired vehicles. Employed by Mexico’s oldest silver mine, Fresnillo Plc, the MDM5000 is boring a mine access tunnel in andesite and shale with quartz intrusions that has defied earlier attempts using roadheaders. The successful operation is the result of extensive discussions between Robbins, who designed and supplied the machine, with TOPO machinery and Fresnillo Plc. View the video of the machine in action here.

“We decided to work with Robbins for their experience. A lot of people have tried to provide these kinds of machines but nobody has done it. Robbins used their experience and their skills to provide us with a rectangular profile machine,” said Fidel Morin, Projects Superintendent for Fresnillo Mine.

The technology is not only useful for the mining industry, but also for many applications in civil tunneling. While other machines have been developed for soft ground, the MDM5000 represents the first successful foray into rectangular hard rock tunneling. “We’re very pleased to add non-circular tunneling to our wheelhouse of solutions that continues to include TBMs, conveyors, cutters, and more. We see applications for the MDM wherever a rectangular profile is needed, such as train tunnels requiring a flat invert. In a traditional circular tunnel, the invert is filled or an invert segment is needed, but with the MDM 30% less rock is required to be removed from the profile,” said Robbins President Lok Home.

With more than 1,700 m of advance thus far at rates up to 52 m in one week and 191 m in one month, the MDM is significantly faster than drill & blast excavation. “We’re making history. Fresnillo is always looking for new technology, and we believe that the usage of the MDM5000 is going to be something extremely successful, not only for our company but also for the industry,” said Morin.

The MDM5000 has undergone major component enhancements during the course of its successful bore at Fresnillo mine. It was first transported to the -695 m level of the mine and underwent final assembly and launch in a cavern, where sections of the MDM were moved by crawlers and pieces were lifted by hoist. The machine is now boring a 270-degree spiral to end above the original tunnel.  It will then be backed up to the original tunnel and continue driving straight ahead.

Developed for use in rock up to 200 MPa UCS, the MDM5000 utilizes disc cutter technology proven on traditional, circular TBMs. During excavation a reciprocating cutterhead and swinging cutterhead motion create a rectangular cross section tunnel.

The MDM offers a number of advantages over drill and blast. MDM tunneling has advance rates roughly twice those of a drill and blast heading, and results in smooth tunnel walls, less overbreak, and minimized ground support. The increased advance rates are partly due to the machine’s continuous progress, unlike drill and blast operations where crews must exit the tunnel during blasting for safety. In addition, simultaneous ground support installation further increases overall advance rates compared with drill and blast operations that must install ground support sequentially.

View the machine boring at Fresnillo mine: https://youtu.be/mgFopWaf220

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