Author: Robbins

Incredible India: Machines on the Move in Agra and Delhi

India’s metro network has undergone extensive growth in recent years, and is showing no signs of slowing. Multiple Robbins machines are part of tunneling work in cities across India, including Agra and Delhi.

Agra Metro: From First Site Acceptance…

On February 16, 2023 the Robbins crew and contractor SAM India celebrated the site acceptance test for the first of two 6.65 m diameter EPB TBMs at Agra Metro. The machine began boring a 1.3 km long tunnel in soft soils, for Uttar Pradesh Metro Rail Corporation Ltd.

To Second Site Acceptance…

With the first TBM well into tunneling, a second 6.65 m Robbins EPB underwent site acceptance on April 13, 2023 to bore a parallel 1.3 km long tunnel in soft soils. The crew gathered for a ceremony before sending the TBM on its way.

To First Breakthrough!

Just a few days later on April 26, 2023 the first machine made an intermediate breakthrough into a station site, completing the Jama Masjid to Agra Fort stretch of the metro. The machine bored a total of 345 m in sand and clay, and broke through to a celebration by the crew and project teams.

New Delhi Metro: Machines Ramping Up

On February 27, 2023 the first of two 6.65 m diameter EPBs for the Delhi Metro (owner is Delhi Metro Rail Corporation) was completed in the Robbins Gurgaon, India facility. The mixed ground machine will bore a 3 km long tunnel through rock with some gravel, sand, silt and clay for contractor Afcons Infrastructure Ltd.

A second machine factory acceptance followed in April 2023. Both machines are scheduled to launch on parallel tunnels this summer.

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WTC 2023

Event Name: ITA-AITES World Tunnel Congress 
Dates: May 12-18, 2023
Location: Athens, Greece
Venue: Megaron Athens International Conference Centre (MAICC)
Stand: 59

Come join us May 12-18 in Athens, Greece for the ITA-AITES World Tunnel Congress, the premiere event for tunneling and underground construction. More than 2,000 professionals are set to take part in the world’s top-attended tunneling conference, where hundreds of technical papers will be presented on the latest topics of interest. Stop by our stand 59 to converse with our expert international team, and find out the latest about our products, projects, and talks at the conference.

Technical Presentations:

Tuesday May 16
Track 2, Theme 4 Mechanized Tunneling
4:30 – 4:50 PM
Mitropoulos Hall
Record-Setting Large Diameter Mixed Ground Tunneling in Turkey: The Eşme-Salihli Railway Tunnel
Presented by Detlef Jordan, Sales Manager Europe

Wednesday May 17
Track 4, Theme 6 Tunneling in Challenging Conditions: Case Histories and Lessons Learned
12:40 – 1:00 PM
MC2 Hall
Lessons Learned During Excavation of the Incredibly Challenging Yin Han Ji Wei Water Diversion Tunnel
Presented by Lok Home, Robbins President

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NASTT No-Dig

Event Name: NASTT No-Dig 2025
Dates: April 30-May 4, 2023
Location: Denver, Colorado
Booth: 441

Join experienced Robbins staff at the largest trenchless technology conference in the world, NASTT No-Dig in Denver, Colorado. 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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Robbins Double Shield Launches in Nepal

In October 2022, China Overseas Engineering Group Co. Ltd and China Railway No. 2 Engineering Group Co Ltd launched a 6.4 m diameter Robbins Double Shield TBM. The TBM is boring the 13.1 km headrace tunnel for the Sunkoshi Marin Diversion Multipurpose Project (SMDMP) located in southern Nepal.  The tunnel is connected to a new 28.6 MW surface powerhouse on the Marin River to alleviate the shortage of power supply in the area. It will also be used for farmland irrigation in the districts of Dhanusha, Mahottari, Sarlahi, Rauthat and Bara in the Terai Plain, diverting water from the Sunkoshi River to the Marin River.  Since the TBM’s launch, it has bored over 500 m, with a best week of 224.6 m, and a best day of 36.6 m.

The headrace tunnel is being bored through granitic rock with maximum overburden of 1,320 m. Geological conditions may include squeezing ground, fault zones, and water inflows. In particular, a major fault zone is located approximately 4 km into the tunnel at Dhanamana Khola. The machine was customized for the conditions, explains Mr. Liu Fengfan, Project Manager for contractor B-2/COVEC: “The TBM shield is a tapered design to reduce the risk of becoming stuck in squeezing ground; there is an enclosed cutterhead design to reduce the collapse of surrounding rock as well. The TBM has overcut capabilities, and a high thrust. It has also been designed to be equipped with an extra high torque cutterhead drive, as well as strong auxiliary thrust to be used in squeezing ground or weak fault zones to keep the machine from becoming stuck.”

As for the major fault zone, to be reached in approximately June 2023, and other zones of concern, Mr. Liu’s plan is well-thought-out: “We have prepared the advance geology forecast along with technical measures and equipment to cope with the extraordinary geological conditions. These include advance drainage holes, pre-excavation grouting (both ordinary and chemical), and other methods based on our experience.  When we reach the major fault zone at Dhanamana Khola we will go slow, with more probe drilling while in the fault zone.”

The tunnel is the machine’s second: on its 12.2km first tunnel (the Bheri Babai Diversion Multipurpose Project/BBDMP), the TBM finished nearly one year early and achieved 1,202 m advance in one month. “The Robbins TBM at BBDMP successfully broke through the 12.2 km tunnel and overcame extraordinary geological conditions especially in fault zones. Its stable and excellent performance and function have been verified very well. We have much confidence in the TBM to be used in SMDMP,” said Mr. Liu.

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Sustainable Tunneling with Rebuilt TBMs

Sustainability in tunneling is more than just a hot topic: current and future tunnel projects can and should seek ways to reduce environmental impacts.  One of the simplest ways to reduce impacts and carbon footprint is with a renewable resource: a tunnel boring machine. TBMs have been proven to last for decades, and can be rebuilt cost effectively project after project with proper maintenance.  In fact, several known, active TBMs are still boring tunnels after more than five decades of use and 50 km of total tunneling.

Just how successful can rebuilt TBMs be? We explore this question through the lens of the DigIndy Project in Indianapolis, Indiana, USA, where contractor J.F. Shea is using a rebuilt TBM to great effect. The 6.2 m diameter Main Beam TBM on that project, originally built in 1980, recently bored the last of more than 40 km of tunnels below the city. During the course of boring, the machine set three world records in its size class of 6 to 7 m, including a best month of 1,754 m.

In this complimentary, 60-minute webinar we discuss rebuilt TBMs as a key to sustainable tunneling with Doug Harding, Robbins Vice President, and Christian Heinz, Project Manager for J.F. Shea. Listen in on our conversation with Julian Champkin of Tunnels & Tunnelling International as we discuss recommendations for rebuilt machine use, and case studies from around the world. The on demand recording is available now. 

WATCH THE RECORDING

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A Clean Solution for Renewable Energy: Small Diameter Hydro Tunnels

Small hydroelectric power projects, with installed capacity up to 10 MW, are a relatively untapped but potentially game-changing source of renewable energy worldwide. In Norway, hydro projects are pioneering the use of small diameter TBMs in hard rock. Compared with drill and blast, TBMs offer increased production rates and reduction in cross section, as well as lowered rock support requirements and reduced project schedules.

The uniquely designed machines are engineered to take on steep gradients, up to a 45-degree angle in some cases. Both shielded and open-type TBM designs have been developed that utilize safety grippers and customized mucking systems to operate at steep grades. This paper will discuss the specialized TBMs and their performance at several projects in Norway, as well as the potential to use this technology throughout Europe and internationally.

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Non-Circular Tunnel Boring for Underground Mine Development

TBMs have been used in mining in decades past, but their use has been limited and sporadic. This has changed in recent years, with TBMs being used at Stillwater Mine, Grosvenor Coal Mine Slopes, and Sirius Minerals potash mine. These machines are all full face, circular TBMs. With their circular bores, these machines have thus far been unable to tackle a larger issue for mines—the need for a flat floor. While the mining industry excavates many more kilometers of tunnel each year than the civil construction industry, typically a flat floor is needed for mining vehicles to traverse.

A novel type of non-circular boring machine is now answering that need with its ability to cut a rectangular profile in hard rock. This cross section allows for use of typical mine trucks and other rubber-tired mine vehicles. It provides more useable space, compared to a circular profile, and minimizes the amount of excavated rock that must be hoisted out of the mine. This machine uses typical disc cutters to cut the rock and has a support structure similar to an open type TBM; however, the cutting geometry is entirely different. The machine is currently cutting an access tunnel at a silver mine.

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Bauma 2025

Event Name: Bauma
Dates: April 7-13, 2025
Location: Munich, Germany
Venue: Messe München
Stand: C2.102

Meet us in Munich, where Robbins will be exhibiting at Bauma, the largest construction machinery trade show in the world. Join us in Hall C2, stand 102 between April 7 and 13, and get the latest on our products and projects. From underground mining solutions to record-setting civil tunneling bores, Robbins is committed to excellence across industries.

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Unprecedented Diameter Change: The Mill Creek Tunnel

At the Mill Creek Drainage Relief Tunnel in Dallas, Texas, USA, a Robbins Main Beam TBM underwent an in-tunnel diameter change for the first time in the industry. The machine went from 11.6 m diameter to 9.9 m diameter through teamwork, perseverance, and top-notch engineering. Watch the video to find out more about the ground-breaking process and unique project.

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Landmark Breakthrough for Robbins TBM ‘Big Tex’

On July 25, 2022, a crowd gathered as a large Robbins Main Beam TBM, dubbed ‘Big Tex’, broke through in Dallas, Texas, USA. The machine and its continuous conveyor system, for the Mill Creek Drainage Relief Tunnel, successfully bored 8 km (5 mi) in chalk and shale at up to 498 m (1,634 ft) advance in one month. “I think when you step back and look at what was accomplished by this team as whole…the overall length and size of this tunnel, the TBM conversion, the everyday grind to keep moving forward…it truly is something to be proud of, professionally and personally. No single individual could reach this milestone. It took a great team of skilled individuals. I am fortunate to be a part of it,” said Nick Jencopale, Sr. Project Manager for contractor JV Southland/Mole.

Good advance rates were not the only cause for celebration: the unique project required a planned in-tunnel diameter change of the TBM from its original 11.6 m (38 ft) to a more compact 9.9 m (32.5 ft). The first-of-its-kind conversion process was undertaken 2.8 km (1.7 mi) into the bore and was not done inside a shaft or pre-excavated portal.  “The TBM conversion was a unique challenge that we were excited about, and ultimately provided a more efficient method for the desired product compared to the alternative options. Hopefully the successful conversion proved that this option can be considered for future tunnel projects,” said Jencopale.

While there were many detailed steps to the conversion process, precision design of the machine was a key aspect.  “We started with a smaller machine, then we made a kit or second skin that was slightly larger. And then when the time came, we just took that skin off. It was essentially that simple,” said Evan Brinkerhoff, Robbins Field Service Manager. The conversion took about four months and was completed in April 2021.

“The Robbins Main Beam TBM (‘Big Tex’) performed consistently throughout the duration of the tunnel excavation. There were very minor issues and little overall downtime as a result of the TBM itself,” said Jencopale. Due to the relatively favorable ground conditions in much of the tunnel, including low rock strength and low abrasivity, only eight disc cutters were changed during the length of tunnel bored at the larger diameter. At the time of diameter change the full dress of cutters was changed, and since that change only 14 cutters have needed replacing. Crews did encounter some fault zones, and installed rock bolts and wire mesh in the tunnel crown as needed.

With the TBM-driven portion of the tunnel now complete, work can commence to remove the machine from the tunnel and install a final lining. The tunnel is a designated critical infrastructure project for the City of Dallas, providing 100-year flood protection for areas of East Dallas that have experienced severe flooding in the past. Construction work is expected to be complete in late 2024/early 2025.

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