Industry News, trenchless projects
Hiroshima Heavyweight Launches on Expressway Line 5
On September 18, 2018, a Robbins mega-sized slurry machine, measuring 13.7 m (44.8 ft) in diameter, made its first cut into hard rock. The epic launch at an urban jobsite was made possible by Onsite First Time Assembly (OFTA) of the TBM in Japan for the Hiroshima Expressway Line 5 project. The contractor, a joint venture of Obayashi-Taisei-Kosei, had a strict timeline of eight months to adhere to when it came to machine assembly. “This deadline was very important. After assembling the TBM, I think OFTA was appropriate for this project,” said Mr. Ryota Akai, Deputy Project Manager for the Obayashi JV.
Due to the project location there were also restrictions on delivering the TBM—in order to meet controlled transportation limits within the city, the TBM had to be divided into small transportable weights and sizes, then assembled in a small jobsite measuring just 30 m (100 ft) wide x 60 m (200 ft) long. The 2,400 metric ton (2,650 US ton) machine will bore 1.4 km (0.9 mi) of the 1.8 km (1.1 mi) long tunnel that, once completed, will significantly improve traffic conditions in Hiroshima.
The massive machine is the country’s first foreign-made large diameter Slurry TBM to excavate hard rock in Japan. “There is a lot of hard rock in Hiroshima,” said Mr. Akai, “and Robbins has a lot of experience boring hard rock.” The machine is expected to encounter granite with rock strengths up to 130 MPa (19,000 psi) UCS. Those involved in the project are excited to see what effect this will have on how Slurry TBMs are used in the future. “The development of this TBM is a milestone,” said Mr. Kiyomi Sasaki, General Manager of Robbins Japan, “it will lead to new tunnel applications worldwide.”
The design of the Slurry machine is robust in anticipation of potentially abrasive rock conditions and water pressures up to 13 bars. “The Robbins machine is very tough, for example the weight is very heavy. The cutterhead, both its material and structure, are very tough. It will not break in hard rock,” said Mr. Akai.
In preparation for the conditions, the machine was designed for 20-bar water pressure. The robust cutterhead was fitted with 20-inch and 17-inch diameter pressure compensating cutters, which utilize a patented design to effectively operate under high pressure. The joint venture intends to change the disc cutters an estimated 10 times during the bore as part of the machine’s maintenance.
Throughout the assembly and launch process the joint venture crew worked with Robbins Supervisors who assisted and provided guidance. “Robbins crews have a lot of experience; they help us every day despite the language barriers. I appreciate it,” said Mr. Akai.
The new Expressway Line 5 tunnel will directly connect Hiroshima’s urban area with a major national highway network and is expected to improve access to Hiroshima Airport. Tunnel completion is planned for 2020.
Image 1: Robbins crews assisted the contractor during Onsite First Time Assembly (OFTA) of the massive Slurry TBM in a jobsite measuring just 30 m (100 ft) wide x 60 m (200 ft) long.
Image 2: The 13.7 m (44.87 ft) diameter Robbins Slurry machine launched on September 18, 2018 in Hiroshima, Japan.
Image 3: Guerin Nolasco of Robbins Field Service looks on during testing of the segment erector inside a mega-sized slurry machine at the Hiroshima Expressway Line 5 project.
Industry News, trenchless products, trenchless projects
Massive XRE Machine breaks through at Akron OCIT
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.
“One of the most challenging aspects of this job was that we launched right into the most difficult part. We had 60 m (200 ft) of soft ground, a very short reach, and then from there we went right into a mixed face for 180 m (600 ft),” said David Chastka, Project Manager for Kenny Construction, a joint venture contractor on the project with Obayashi. “It took everybody we had in the industry, everybody from Robbins, to fight through that first 240 m (800 ft).”
The TBM was designed for the project’s geology, which transitioned from soil to partial face shale to full face shale rock. The Crossover XRE included features of both EPB and Hard Rock Single Shield TBM types, with a versatile cutterhead that could be configured for hard rock or soft ground conditions. While in soft ground and mixed face conditions the machine operated in closed mode, but once it hit solid rock crews switched excavation to open mode. “The machine had the power to get to the other side and made advance rates we never thought we were going to get. It was very successful in hard rock,” said Chastka. Advance rates once in full-face shale rock reached a high of 34 m (111 ft) in one day (two 10-hour shifts). Muck removal was achieved using a Robbins continuous conveyor, and conveyor availability remained high throughout the project.
“I am most proud of the team that I have had the pleasure of being a part of,” said Don Smida, Robbins Field Service Technician. The overall scope of a project of this scale is immense, and the amount of daily cooperation & hard work that has been asked of The Robbins Company, the local unions, city staff, and Kenny-Obayashi is extremely important in reaching our common goals. I think we should all be proud of our teamwork going forward from a successful completion of the tunnel and into a successful disassembly of Rosie.”
Now that tunneling is complete, the machine will be disassembled and removed from its retrieval shaft this autumn. “The Ohio Canal Interceptor Tunnel is the largest public improvement project in our City’s history and a significant investment in our environment and infrastructure that will benefit Akron residents and businesses for generations to come,” said the City of Akron’s Mayor Daniel Horrigan. “Projects of this kind are inherently dangerous, and I am incredibly proud that the tunneling portion was completed without any major injuries, thanks to a dedicated team of professionals. And although Robbins is an international company with worldwide impact, we were pleased to be able to work with a local Northeast Ohio firm on this significant project.”
The OCIT Project for the City of Akron, Ohio, USA consists of the construction of a conveyance and storage tunnel system to control Combined Sewer Overflows (CSOs) for several regulators in the downtown Akron area. The EPA-mandated project includes the 1.89 km (1.17 mi) conveyance and storage tunnel, as well as drop shafts, diversion structures, consolidation sewers, and related structures.
Image 1: On August 29, 2018, a 9.26 m (30.4 ft) diameter Robbins Crossover TBM broke through at the Akron Ohio Canal Interceptor Tunnel (OCIT).
Image 2: Personnel inspect the Robbins Crossover XRE TBM “Rosie”, named for Rosie the Riveter, after the breakthrough.
Image 3: A crew member cleans the cutterhead of the Robbins Crossover TBM following its breakthrough on August 29, 2018.
Image 4: The Robbins Crossover XRE machine—the first such machine to operate in the U.S.—achieved advance rates of up to 34 m (111 ft) per day in two 10-hour shifts.
Image 5: The 9.26 m (30.4 ft) diameter Robbins Crossover TBM was designed and built in Robbins’ Solon, Ohio, USA facility.
Industry News, trenchless projects
Nepal’s First TBM bores 1,000 Meters in One Month
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 ft) in one month and has been averaging an impressive 800 m (2,630 ft) 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).
The decision to use a TBM for the BBDMP project—designated by the government as one of Nepal’s 11 National Pride Projects—was a departure for a nation where drill & blast has long been the preferred tunneling method. Early studies done on the tunnel path predicted that drill & blast excavation of the 12.2 km (7.5 mi) tunnel would take close to 12 years to complete. The tunnel is located in the Siwalik Range, part of the Southern Himalayan Mountains, where geology consists of mainly sandstone, mudstone, and conglomerate.
Mr. Wang Wu Shui, General Manager for COVEC Nepal, cited several factors that have contributed to the good advance rates so far, “In China, there is a proverb about TBM construction: ‘geology is the premise, equipment is the foundation, and talents are the key’. The great advance rates achieved at present mainly lie in preliminary planning, process control, and professional construction personnel.” Shui added that technical training and guidance are provided for each position so that all personnel can fully understand their job and team responsibilities. If unforeseen circumstances arise and there is no operator for a certain position, others have enough training to fill the role.
To ensure the best TBM performance and to prevent downtime, machine maintenance occurs daily at a fixed time. Geological engineers are sent to analyze the ground conditions twice daily so that construction personnel can adjust the tunneling parameters and prepare for auxiliary measures if geological changes are predicted.
The ground conditions during the record-setting month consisted mainly of sandstone and mudstone, but that is set to change. At about the 5.8 km mark, the machine will encounter a major fault zone known as the Bheri Thrust. Clay and water ingress are expected throughout the fault, which is about 400 to 600 m wide.
COVEC Nepal are prepared for the conditions and have worked out efficient tunneling logistics to decrease downtime. “The two working procedures of tunneling and segment erection are carried out simultaneously under the double shield tunneling mode, and the time to erect a ring of segments is 15 minutes in general,” said Shui. “Under the single shield tunneling mode, segment erection comes after tunneling in a sequential process, but the segment erection time is still about 15 minutes.” To further reduce time, consolidation grouting is carried out in advance during daily maintenance to avoid the impact of downtime for grouting on the overall construction progress.
Once complete, the BBDMP will irrigate 60,000 hectares of land in the southern region of Nepal, and benefit an estimated 30,000 households. It will divert 40 cubic meters (1,400 cubic feet) of water per second from Bheri River to Babai River under a head of 150 m (490 ft) using a 15 m (49 ft) tall dam, providing year-round irrigation in the surrounding Banke and Bardia districts. The water will also be used for hydroelectricity, with a generating capacity of 48 MW benefiting the country with NPR 2 billion (20 million USD) annually. The initial success of the TBM operation has already inspired developers and contractors to opt for TBMs over conventional excavation methods on upcoming Nepalese tunnels.
Image 1: A 5.06 m (16.6 ft) Robbins Double Shield TBM has bored over 1,000 m (3,280 ft) in one month at Nepal’s Bheri Babai Diversion Multipurpose Project (BBDMP).
Image 2: The COVEC Nepal crew celebrate the record-setting month of over 1,000 m (3,280 ft) for the Robbins Double Shield TBM boring the BBDMP tunnel.
Image 3: An overhead view of the BBDMP jobsite, located in Bardia Wildlife Reserve, a sanctuary home to tigers, rhinos, elephants and many other types of vulnerable flora and fauna.
Image 4: Launched in summer 2017, the Robbins TBM is the first ever to operate in Nepal and has garnered much national attention for its successful operation.
Industry News, trenchless projects
Long Pull Avoids Draining Major Wetland
Sliplining is completed by installing a smaller, HDPE pipe into a larger host pipe, grouting the annular space between the two pipes, and sealing the ends. The trenchless method is generally a cost-effective rehabilitation method to replace water and sewer force mains.
The original design was to drain the entire wetland that had formed since the original construction of the 36-inch water main and split the slip lining into multiple sections. However, Murphy Pipelines designed and sliplined the entire length in one pull allowing the wetland to remain untouched.
Powell River, BC located in inaccessible area requiring pipe, equipment and workers reach only by ferries.
Wellpoints set up at insertion pit.
Pull head fused on. Long sections of HDPE pipe staged on old mining road.
Pulling winch set up ready to start sliplining.
Click here to read the case study on Sliplining in Powell River, BC Canada.
Industry News, trenchless projects
The City and County of Denver has designed the 33rd Street Outfall Storm Sewer to reduce flooding concerns between Downing Street and the Platte River along 33rd Street and the surrounding neighborhoods. The project is being released in four phases over three years, and BTrenchless has completed the first two phases, installing the storm sewer from the Platte River to the intersection of 33rd and Blake.
The pipeline is a combination of large box culverts, 120” HOBAS pipe, smaller reinforced concrete pipe, and steel casings. The highlight of the first phase was construction of a precast 11’ x 8’ concrete box culvert across Brighton Blvd. while maintaining a constant flow of traffic. The second phase included a 220’ long tunnel, ten foot in diameter, under the Union Pacific Railroad Yard and the RTD Commuter Rail. It also included side-by-side 96” diameter steel tunnels under Blake Street and a 450 foot long, 51” HOBAS storm lateral via a microtunnel method.
The diversity of this project allowed BTrenchless to utilize three different types of tunnels and capitalized on the vast resources of both people and equipment to successfully complete this complex and high profile project. In the course of the first two phases, nine different crews and four different superintendents had a part in the overall success of the project, each capitalizing on their various areas of expertise.
Click on photos to view larger images. Be sure to notice Morty the Tunnel Rat in the top photo supervising the project!
Industry News, trenchless projects
Massive Metro Project Will Improve Traffic and Rail Congestion in One of India’s Largest Cities
On June 11, 2018, a Robbins Crossover XRE destined for Line 3 of India’s Mumbai Metro arrived in Mumbai port following a successful factory acceptance test in April. The machine, combining features of a hard rock Single Shield TBM and an Earth Pressure Balance Machine, is one of two 6.65 m (21.8 ft) Crossover machines that will bore under contract UGC-01. Operation of these two machines will be carried out by Larsen & Toubro, part of the Larsen & Toubro -Shanghai Tunnel Engineering Co Joint Venture (L&T-STEC JV). The Robbins Company will provide key personnel for the initial boring phase. “During the factory acceptance testing, we observed that the machine and back-up system are robust enough for hard rock tunneling,” stated Palwinder Singh, Head of Tunnel Operations for L&T-STEC JV.
During the bores, consisting of parallel 2.8 km (1.7 mi long) tunnels, geologic conditions will include mixed ground and possible water pressures up to 2 bar. According to Singh, “A Crossover XRE was chosen because of the expected geology,” which includes basalt rock and transition zones consisting of black carbonaceous shale, tuff, and breccia. Rock strengths are anticipated to range between 15 MPa and 125 MPa (2,200 and 18,100 psi) UCS. The machines will bore with only 15 to 20 m (50 to 70 ft) of cover above the tunnel and the structure will be lined with reinforced concrete segments in a 5+1 arrangement.
The metro tunnels will run between the Cuffe Parade Station and Hutatma Chowk station, passing through the Vidhan Bhavan and Church Stations. Both Crossover machines will be launched from the same 25 m (82 ft) deep by 22 m (72 ft) long shaft at the Cuffe Parade Station. “The limited length of the shaft requires running the TBMs for the first 100 m (328 ft) with some or all the back-up decks at the surface,” said JP Bayart, Robbins Project Engineer. “The TBMs and back-up systems are connected with umbilical cables and hoses.”
The TBMs will begin their excavation in hard rock mode. “Each cutterhead is optimized for operation in rock, as this is what is expected. The machines can also operate in soft ground thanks to the screw conveyor with bulkhead gate and discharge gate,” said Bayart. “The Robbins Torque-Shift System, consisting of two-speed shifting gearboxes coupled to the main drive motors, allows for the high cutterhead torque required for soft ground operation.” The face of each machine is equipped with six muck buckets and six large internal muck loading plates. This design, in combination with the screw conveyor located at the centerline of each machine, will allow for the option of fully emptying the cutterhead chamber, resulting in minimal wear when EPB mode is not required. Muck will be removed from the tunnels via muck cars.
Assembly and launch preparations for the first XRE TBM began on 20 June and are estimated to take about six weeks. The second Robbins XRE TBM underwent factory acceptance testing at the end of May and will arrive at the jobsite at the end of July for its assembly. “Our target is to achieve an average of 250 m (820 ft) of boring per month,” said Jim Clark, Robbins Projects Manager India. “The target to complete the boring operations is 20 months, which includes the additional time required for the short start-up using umbilicals on the initial drives, dragging the machines and re-launching through three stations.” Contractor L&T plans to work crews on double shifts to cover a full day of operations in order to keep to this timeline. The machines will join two Robbins Slurry machines boring a separate contract of the Mumbai Metro Line 3. The first of those machines will be launching in August 2018. The Metro Line 3 project as a whole is estimated to be completed by 2021.
Image: Robbins and contractor personnel stand proudly in front of the first of two Robbins 6.65 m (21.8 ft) diameter XRE TBMs during the factory acceptance test.
