On May 23, 2019, a celebration was in order: The last of six 8.93 m (29.3 ft) diameter EPBs had completed excavation at Lot 4 of Mexico City's Tύnel Emisor Oriente (TEO), a feat marking the completion of ten years and 62.1 km (38.6 mi) of tunneling. "We are proud of having successfully finished the excavation, despite all the adversities we faced, such as large inflows of water, hydraulic loads and constant changes in geology. We solved these by adapting the excavation mode according to each type of geology found," said Hector Arturo Carrillo, Machinery Manager for Lot 4 contractor Carso Infraestructura y Construcción (CARSO).
Crossover TBM crosses 48 fault zones in Turkey
XRE Machine completed National Priority Water Line set to go live in March
Excavation of Turkey's longest water tunnel came to an end on December 18, 2018. To get there, a 5.56 m (18.2 ft) diameter Robbins Crossover (XRE) TBM and the contractor JV of Kolin/Limak had to overcome dozens of major fault zones and water pressures up to 26 bar. The completed national priority water line is set to go into operation in March 2019.
The 31.6 km (19.6 mi) long Gerede Water Transmission Tunnel is an urgently needed project due to severe and chronic droughts in the capital city Ankara. Its final leg, a 9.0 km (5.6 mi) section of extremely difficult ground including sandstone agglomerate, limestone and tuff, was just one section in the middle of a tunnel widely considered to be the most challenging ever driven by TBMs in Turkey. "I've had the chance to study and visit the majority of mechanized tunnelling projects in Turkey since the 1980s. The Gerede project is one of the most challenging projects among them," said Dr. Nuh Bilgin, Professor of Mine and Tunnel Mechanization at Istanbul Technical University and Chairman of the Turkish Tunnelling Society.
The Robbins XRE TBM was called in to complete the tunnel, which was at a standstill after using three Double Shield TBMs from another manufacturer. Those machines encountered incredibly difficult geology including massive inrushes of mud and water. The Kolin/Limak JV had to develop a new strategy given the unexpected ground conditions. They contacted The Robbins Company, who suggested a Crossover (Dual-Mode Type) TBM for the remaining section of tunnel. "The Crossover TBM provided great ease and versatility during the entire project with frequently changing ground conditions. The TBM was equipped with features such as increased thrust, two-speed gearbox, and modular screw conveyor. It was capable of giving the necessary responses in different geologies, which was our most important asset in achieving our goal," said Barış Duman, Project Manager for the Kolin - Limak JV.
"The challenging part for us was to design and manufacture a TBM that could complete the difficult section of the Gerede Tunnel where two other competitor TBMs had failed," said Yunus Alpagut, Robbins representative in Turkey. The specialized machine was designed to statically hold water pressure up to 20 bar, a failsafe that none of the standard Double Shield TBMs had been equipped with. A convertible cutterhead was also provided that was designed for ease of conversion between hard rock and EPB modes, and with cutter housings that could be fitted with either disc cutters or tungsten carbide tooling. To cope with difficult ground, the Gerede machine was also equipped with the Torque-Shift System, multi-speed gearing allowing the machine to function as either an EPB or a hard rock TBM. This function is done by adding another gear reduction--heavy duty pinions and bull gears accommodate high torque at low speed, allowing the machine to bore through fault zones and soft ground without becoming stuck.
The Crossover machine was assembled in spring 2016 after crews excavated a bypass tunnel to one side of one of the stuck Double Shield TBMs. An underground assembly chamber allowed the machine to be built in the tunnel using Onsite First Time Assembly (OFTA). "The logistics of getting components through the existing tunnel were the most challenging thing. The assembly chamber was 7 km (4 mi) from the portal. The water inflow of 600 l/s (159 gal/s) made it difficult to get the materials to the machine," said Glen Maynard, Robbins Field Service Site Manager.
Despite the challenges, the machine began boring in summer 2016 and within the first 50 m (160 ft) of boring had successfully passed through the section that buried the original Double Shield TBM. The machine was required to be used in EPB mode as it encountered water pressures up to 26 bars, alluvium, flowing materials, clay and a total of 48 fault zones. Water pressure was lowered by draining the ground water through the rear shield probe drill ports, which were equipped with normally-closed ball valves. Probe drilling was done on a routine basis to get through the ground conditions. "Together with the difficult geological conditions the travel time to reach the TBM within the tunnel had effects on TBM performance. Despite this constraint, the tunnel excavation achieved a best day of 29.4 m (96.5 ft), best week of 134.6 m (441.6 ft) and a best month of 484 m (1,588 ft)," said Duman.
"We had many challenging areas with water and high pressures up to 26 bar along with alluvial material in fault zones. Ground pressure on the shield body caused squeezing conditions in clay. In these regions, we were able to quickly pass through by keeping the TBM advance rate, cutterhead rpm and screw conveyor rotation speed at the ideal level. Ultimately, we think our decision to select a Crossover TBM was correct," continued Duman.
With tunneling complete, the pipeline is on track to open in March 2019. The tunnel will convey water from the Gerede River to Çamlıdere Dam, which provides potable water for the Ankara city water system.
More from Tunneling
In April 2019, a Robbins 3.5-m (11.5-foot) diameter Main Beam TBM broke through into open space, completing its 2.8 km (1.7 mi) long tunnel. It was not the first time the machine had encountered open space: twice during tunnelling, the machine hit uncharted caverns, the largest of which measured a staggering 8,000 cubic metres (283,000 cubic feet) in size.
On October 4, 2018, onlookers watched as a 3.8 m (12.5 ft) diameter Robbins Main Beam TBM completed its epic journey. The TBM, christened "Driller Mike", after local rapper and activist "Killer Mike", overcame extremely hard rock conditions along a curving 8.0 km (5.0 mi) tunnel to bolster the city of Atlanta, Georgia, USA's water supply.
On August 29, 2018, a 9.26 m (30.4 ft) diameter Robbins Crossover (XRE) TBM crossed the finish line at the Akron Ohio Canal Interceptor Tunnel (OCIT). A press day followed on September 5, where companies and members of the media were invited to view the giant machine. The machine — dubbed "Rosie" in honor of Rosie the Riveter, an icon representing American women who worked in factories and shipyards during World War II — overcame tough ground conditions during the bore.
Nepal's first tunnel boring machine, a 5.06 m (16.6 ft) diameter Robbins Double Shield, is living up to the nation's high expectations. The TBM, supplied in summer 2017 for the Bheri Babai Diversion Multipurpose Project (BBDMP), recently bored over 1,000 m (3,280 feet) in one month and has been averaging an impressive 800 m (2,630 feet) per month. The project is owned by the Government of Nepal's Department of Irrigation (DOI) and operated by contractor China Overseas Engineering Group Co. Ltd. Nepal Branch (COVEC Nepal).
In Chicago, Illinois, USA Kenny Construction is nearing completion on the Albany Park Stormwater Diversion Tunnel. The project, owned by the Chicago Department of Transportation, will divert water from the Albany Park neighborhood, which has long been plagued by flooding. Plans for the tunnel began in 2013, after flood conditions became so severe that residents had to be evacuated from the area by boat. The tunnel is expected to be functional by April 2018.
Whether it's a world record with the longest railway tunnel on earth at the Brenner or the epoch-making Gotthard project, the business of mechanized tunnel boring through hard rock is currently reaching new heights in Europe. Now Scandinavia is discovering the advantages of mechanized tunnelling. With the breakthrough at the Ulriken Tunnel, the first major tunnel project in Norway using a Herrenknecht Gripper TBM has been successfully completed.
Large underground projects such as rapid transit tunnels are today being built through highly congested areas, both above and below ground. One of the most complex challenges involves accurately locating existing utilities during the design phase and discerning whether the utility can be accommodated or if it must be relocated.
With the breakthrough of the last two tunnel boring machines into the target pit in Oberhausen-Biefang on June 12, 2017 the tunnel and pipe jacking work for the Emscher sewer has been completed. Over a period of 25 years numerous Herrenknecht tunnelling machines and a wide range of additional equipment were successfully used in the Europe-wide unique environmental and sewage project of Emschergenossenschaft.
Los Angeles is a vibrant center of international film art and innovation - not just on the surface. The area below ground is the scene of state-of-the-art engineering achievements. German high-tech machines from Herrenknecht are creating underground arteries for the American city. Tunnel boring machine (TBM) , Harriet successfully completed her drive for the Crenshaw/LAX Transit Project in April 2017. Angeli just finished digging the first of two tunnels for the Regional Connector Transit Corridor on July 18th. From spring 2018 onward the tunnel boring stars will have additional company: for each of the "Purple Line Extension Sections 1 + 2", two more Herrenknecht TBMs will be working their way through the difficult ground. All three projects are part of the strategic subway extension in L.A. to relieve the traffic above ground.
A Robbins TBM, recently christened “Augustine”, is being commissioned to undertake its eighth bore after being launched by contractor Eiffage Civil Engineering on March 3. The TBM, which was extensively modernized and upgraded during the rebuild for the Galerie des Janots project in La Ciotat, France, has previously completed seven other successful projects across Europe and Hong Kong. This time, it will bore the Janots gallery to improve access to water in the communities east of the Aix-Marseille-Provence metropolis (Cassis, Roquefort-la-Bédoule, La Ciotat and Ceyreste). "It’s a single machine 3.5 meters (11.5 ft) in diameter, 250 metric tons (275 US tons), and 135 meters (443 ft) long, that will work 24 hours a day for almost 10 months during this operation,” says Marc Dhiersat, Project Director of Galerie des Janots for Eiffage.
McLaughlin launched its biggest machine to date at the CONEXPO-CON/AGG 2017 trade show. The McL-60 Workhorse is a 60-inch (152.4-cm) auger boring machine designed with operator convenience in mind. The low-profile engine design, remote control operation and Rabbit Travel help water, sewer and pipeline contractors install large-diameter casings at a lower cost than directional drilling
McLaughlin introduced the groundbreaking Steerable Rock System (SRS) at the CONEXPO/CON-AGG 2017 trade show. The SRS is the auger boring market’s first steerable head designed to navigate not only solid rock but difficult fractured rock conditions as well. Engineered to operate in rock up to 25,000 psi, the SRS allows operators to maneuver auger boring machines even in the toughest ground conditions for an on-grade bore.
Chile’s Los Condores HEPP is a high cover, hard rock challenge, with 500 m (1,640 ft) of rock above the tunnel and a high-altitude jobsite 2,500 m (8,200 ft) above sea level. As of January 2017, a 4.56 m (15.0 ft) Robbins Double Shield TBM had completed boring its 900 m (2,950 ft) long access tunnel and was well on the way to boring the first section of headrace tunnel. The machine embarked on its journey on May 27, 2016, and has since excavated over 1,300 m (4,270 ft) of tunnel in total.
To achieve guided boring steel casing installations in deep, densely compacted ground and soft rock, Akkerman announces the newest solution in the Guided Boring Machine (GBM) equipment line, the Guide Rod Swivel (GRS-50) family of cutter heads with a universal bearing swivel. The robust GRS-50 family contains four sizes of high thrust bearing upsizing tools able to withstand up to fifty tons of continuous thrust loads on guided boring, guided auger boring, and soft rock pilot tube projects.
After an Onsite First Time Assembly (OFTA) lasting just 2.5 months, Atlanta Georgia, USA’s newest TBM, dubbed “Driller Mike”, made its initial startup on October 13, 2016 and ramped up to full production two weeks later. Atlanta’s Mayor Kasim Reed and city officials gathered with local and national media to celebrate the occasion. The 3.8 m (12.5 ft) diameter Robbins Main Beam TBM is now boring the 8.0 km (5.0 mi) Bellwood Tunnel after being walked forward 100 ft into a starter tunnel. The Bellwood Tunnel path will travel from an inactive quarry and run below a water treatment plant and reservoir before ending next to the Chattahoochee River.
On Tuesday, September 6, 2016, one of the longest-running Robbins TBMs embarked on its most extensive project yet. The 6.2 m (20.2 ft) Main Beam machine, owned by the Shea-Kiewit (S-K) JV, is boring the 8.5 km (5.3 mi) long White River Tunnel as the first in the next phase of the DigIndy wastewater tunnels below Indianapolis, Indiana, USA. In addition to that work, the machine will bore the Lower Pogues Run, Fall Creek, and Pleasant Run Tunnels—a scope of work totaling about 28 km (17 mi) through limestone and dolomite rock.
Equipment maintenance is a topic that no contractor particularly wants to address, but in light of the ever growing need to maximize production and cut down time it is extremely important. Your equipment will only continue to work properly if you take the time to perform simple routine maintenance.
On June 8, 2016, one of two 6.4 m (21.0 ft) diameter mixed-face EPB machines broke through at Namma Metro. After being launched in March 2015, the TBM named Kaveri made its way through its difficult 750 meter (2,460 ft.) drive from Chickpet to Majestic. Sister machine Krishna, launched in December 2015 is not far behind, and is expected to break through in approximately two months.
Divers must constantly keep track of their depth and dive time in order to prevent decompression sickness, otherwise known as the bends. Because divers are breathing air while they are pressurized by the surrounding water, the diver’s tissues absorb gases (mostly nitrogen) from the breathing air. The deeper the diver goes and the longer he stays there, the more gas his body absorbs. When the diver returns to the surface and the pressure is relieved, these accumulated gases start to leave the body. If the pressure is relieved too quickly, bubbles can form. These bubbles in the diver’s tissues are the cause of decompression sickness. Nitrogen bubbles can cause joint pain and in extreme cases, impaired brain, spinal cord and lungs function.
Most tunnelling contractors don’t have to worry about planes landing on the ground above them. But that – and much more – made a recent sewer-twinning project carried out by Oakville, Ontario-based CRS Tunnelling much different from your average construction job.
It’s not often that a company can lay claim to two major accomplishments within the space of just a few months but that is what happened last summer with two significant microtunnelling projects completed in Calgary and Toronto by Ward & Burke Microtunnelling Ltd.
The recent construction of a major trunk sewer line in Edmonton to accommodate new development is significant for a number of reasons, most significantly that it is the first time a Chinese company has done tunnelling work in North America.
Topcon Positioning Group announces the launch of Topcon Delta, its new deformation monitoring solution for construction, tunneling and mining. Topcon Delta is a system of software and hardware components, which delivers accurate and reliable monitoring measurements and associated reporting to provide protection of assets during works.
In a large November 2015 ceremony attended by the mayor of Montreal,, and representatives from local media outlets, the Rosemont Reservoir tunnel construction came to a close. The long-awaited project, more than 38 years in the making, gave cause for celebration as crew members crowded around the cutterhead of the 3.0 m (9.8 ft) diameter Double Shield TBM that had emerged into an exit shaft.
Bertha, the SR 99 tunnelling machine, is now tunnelling in Seattle soil after breaking through the access pit wall on January 6th. After being out of commission for about two years, Seattle Tunnel Partners (STP) has mined 73 feet and installed 12 concrete tunnel rings since Bertha first moved forward in the pit on Dec. 22.
Officials announced on November 27 that tunnelling has completed on the Evergreen Line, a new addition to Metro Vancouver's light rail system known as SkyTrain.
The State Route 99 tunneling machine entered its next phase of testing early Tuesday, Dec. 22, near Pier 48, moving forward and installing a tunnel ring at the bottom of the 120-foot-deep pit crews built to access and repair the machine. Seattle Tunnel Partners, the Washington State Department of Transportation's design-build contractor for the tunnel project, plans to tunnel a short distance further in the access pit tunnel before giving crews a break for the holidays.
A crowd of crew members gathered to celebrate in front of a newly-emerged hard rock TBM on December 10 in northern Norway, but their celebration was about more than just a breakthrough. The 7.2 m (23.6 ft) diameter Robbins Main Beam machine had traversed hard rock, water inflows, and more to become the first TBM used in the country since over 20 years.
Tunnelling could resume by Christmas on the Highway 99 tunnelling project in Seattle.
In June, ASI Marine (ASI) personnel conducted a remotely operated vehicle (ROV) underwater inspection of the Cheves Hydropower Tunnel in Peru and ended up breaking the ASI company record for the deepest flooded tunnel inspection at 570 metres water depth. The Cheves Hydropower Project is being developed by Empresa de Generacion Electrica Cheves S.A., a wholly-owned subsidiary of Statkraft, a Norwegian electricity company.
In Bend, Oregon, local contractor Stadeli Boring & Tunneling had a unique set of circumstances for a new gravity sewer interceptor. “We had a contract with general contractor Taylor NW to furnish and install 323 feet (98 m) of 36-inch (900 mm) steel casing under railroad tracks. Line and grade were very crucial, and the tolerances were very close. We had to be right on,” said Larry Stadeli, president and owner of Stadeli Boring & Tunneling. In addition to those parameters, the job was also in solid rock.
The Bosphorus road tunnel project which broke through in August in Istanbul, Turkey is a major achievement on one of the world’s biggest and most challenging tunnel drives. At 13.66 metres diameter and 11 bar of water pressure in fractured rock and soft ground, the 3.34-kilometre-long bore was unprecedented and required skillful engineering and advanced TBM technology.
How much power does it take to run a city? In a major urban centre like Toronto, it turns out, quite a lot. With a metropolitan-area population that recently cracked six million, Canada’s largest city is facing ever-increasing demands for base and peak loading. That is the case especially in the downtown core, where dense residential and commercial development has stretched power resources to the point where the need to relieve capacity constraints necessitated an additional transformer station in Toronto’s crowded south core central business district.
Kuala Lumpur's karst soil riddled with fissures and crevices is a real challenge for tunnel builders. Herrenknecht, developed for Klang Valley MRT Project in Malaysia´s capital in collaboration with MMC-Gamuda Joint Venture a new type of machine. The Variable Density tunnel boring machine can be operated in four different tunnelling modes and thus perfectly adapted to the different conditions. After nearly two years of tunnelling, in mid-April 9.5 kilometers of tunnel were completed and the new technology had proven itself. A major breakthrough for Kuala Lumpur’s Metro and for mechanized tunnelling in difficult soft ground.
Tunnelling for the new Port Mann water main deep below the Fraser River is now complete, and the massive tunnel boring machine, named Squirrel, was removed from the river on July 17.
Robbins announced its Crossover Series of TBMs, a line of field-tested, rugged Dual Mode-type machines. Crossover TBMs feature aspects of two TBM types, and are ideal for mixed ground conditions that might otherwise require multiple tunnelling machines. The XRE (standing for Crossover Rock /EPB) is the most common type of hybrid machine, and features characteristics of Single Shield Hard Rock machines and EPBs for efficient excavation in mixed soils with rock.
Two projects in which microtunnelling machines from Herrenknecht are driving new sewers have been awarded the "GSTT Award 2015" by the German Society for Trenchless Technology e.V. (GSTT). The special award "International Project" was given to the National Water Company of Saudi Arabia. At their unusual construction site in Mecca two Herrenknecht EPB shields with an individual remote monitoring system are in use. The Emschergenossenschaft received the GSTT Award “Gold” for a construction of a section between Dortmund and Bottrop as a part of the Emscher renaturation. Since 2013 several Herrenknecht utility machines have been driving a new sewer system there.
Akkerman has introduce the 5200 Pump Unit, the most essential element of the Tunnel Boring System. This flagship product has been improved in several essential areas while retaining the best qualities of its predecessors, to achieve optimal pipe jacking performance.
Las Vegas, the glittering city of luck with its fascinating fountains, draws 90 percent of its water from Lake Mead. The largest reservoir in the United States is fed by the Colorado River. The areas around Las Vegas, however, are taking more from the lake than flows into it as snow melt and rain water from the Rocky Mountains. During the 14 years of drought, the water level has dropped by 35 metres. The two existing water intakes for the Las Vegas Valley are in danger of running dry, and Intake No.1 could be at risk next year. It is now only 24 feet (7 metres) below the lake level.