Industry News, trenchless projects
Tough TBM and Team overcome the odds with Atlanta breakthrough
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.
The new tunnel brings the Atlanta Water Supply Program one step closer to increasing the city’s water capacity to between 30 and 90 days depending on daily usage. “Our schedule for the project was very aggressive but the project team stayed together to overcome issues related to the mining of the tunnel,” said Bob Huie, Project Director for the PC Russell JV, the Construction Manager at Risk (CMAR) for the project.
The unique structure of the project team is credited with the overall project success despite challenges. “I’m proud of our team. They had obstacles and challenges and challenging ground, but they stuck together and didn’t give up, and they were successful. There was great leadership and supervision all around,” said Larry Weslowski, Tunnel Superintendent for the PC Russell JV.
The project is only the third such large construction project in the U.S. to use the CMAR structure. The PC Construction/HJ Russell JV was selected as the CMAR for the project, who then purchased the Robbins Main Beam TBM for the tunnel. The designer for the construction works including tunnel and shafts, JP2—consisting of Stantec, PRAD Group, Inc., and River 2 Tap—specified the hard rock TBM. Operation and assembly of the TBM was then sub-contracted to the Atkinson/Technique JV.
The robust TBM was assembled using Onsite First Time Assembly (OFTA) at the massive Bellwood Quarry site with help from Robbins personnel. “The guys built everything per the specs to help with scheduling. It was a challenge but there was no negativity during the process,” said Weslowski. Despite summer temperatures hitting 43 degrees Celsius (110 degrees Fahrenheit) and 100 percent humidity, the TBM was ready to launch by October 2016.
Hard granitic rock challenged the 19-inch disc cutters from the outset. “There was ground so hard that it would take eight hours to go 1.5 m (5 ft). It was between 117 and 310 MPa (17,000 and 45,000 psi) UCS. The beginning of the job was tough,” said Weslowski, but he added that once the learning curve had been overcome “they started breaking project records left and right towards the end. We got a best day of 38.4 m (126 ft). Rates just kept increasing.”
Other challenges included groundwater encountered during tunneling. “We did encounter groundwater contamination that required remediation. This remediation work was completed successfully,” said Huie.
With tunneling complete, the USD $300 million project for the City of Atlanta’s Department of Watershed Management is on track to meet its scheduled overall completion date of September 2019. The project will turn the inactive Bellwood quarry into a 9.1 billion liter (2.4 billion gallon) raw water storage facility connecting with the Chattahoochee River and various water treatment facilities.
Image 1: The PC Russell JV and Atkinson/Technique JV celebrate the breakthrough of the Robbins TBM on October 4, 2018 in Atlanta, Georgia, USA.
Image 2: The Robbins TBM and 19-inch cutters overcame exceedingly hard granitic rock at strengths up to 310 MPa (45,000 psi) UCS.
Image 3: Crews are proud of the coordination required to overcome a host of challenges, including tight tunnel curves and contaminated groundwater that required remediation.
Image 4: The robust TBM was assembled using Onsite First Time Assembly (OFTA) at the massive Bellwood Quarry site with help from Robbins personnel.
Industry News, trenchless projects
Project profile submitted by Insta-Pipe – Trenchless Pipe Repair using the Pull in Place pressure liner “PRIMUS Line”.
Client: Southwest Suburban Sewer District
Engineering and Installation Partner: Insta Pipe – Trenchless Pipe Repair, Olympia, WA
Year of Construction: May 2016
Type of Project: Rehabilitation of an 8 inch sewer force main with 60psi rating and vertical bends in host pipe alignment
Our services:
- Supply and delivery of the flexible low Pressure 8 inch Primus Liner (ANSI/NSF 61 approved)
- Delivery of the 8 inch Primus Line low pressure connectors (150 lbs)
Task: After a recent emergency repair the Southwest Suburban Sewer District decided to upgrade the existing primarily ductile iron line. The project was located at Shorewood Dr. SW corner SW 125th and runs down the hill to pump station 7, which is located between two houses next to the bay. The section to be rehabilitated was 262 linear feet long and encloses multiple vertical bends of up to 22 degrees with a maximum operating pressure of 60 psi. Since the pipe runs on a steep hill and through people’s gardens in a residential area, a traditional open trench solution was not reasonable. Therefore, the sewer district had to choose between two trenchless technologies: Primus Line® and CIPP.
Rehabilitation System: After an open communication with Primus Line and Insta-Pipe, the Southwest Suburban Sewer District decided to use the Primus Line® system, a flexible relining solution for the trenchless renovation of pressure pipes. The system convinces with its ability to negotiate bends, the minimally invasive construction footprint and the short installation time. In this particular case, the budget was reduced by over 50% compared to the lowest offers with CIPP and was even cheaper than the Engineer’s Estimate.
Project Description: The decision was to install a Primus Line® DN 200 ND with a nominal diameter of 8 inch and a nominal design pressure of 290 psi. Since the technology works with an annular space to achieve long insertion lengths and negotiate bends, the liner provides an actual outer diameter of 7.165 inch and inner diameter of 6.693 inch. According to the calculation of the technical department of Primus Line, the pressure rating of the system through the bends is 217 psi and thus capable of accommodating the maximal operating pressure of 60 psi along the entire pipe route. To complete the system, the low pressure connectors with an operating pressure of 150 psi were used to guarantee a durable and tensile strong connection.
In a first step, the two excavation pits for the installation of the Primus Line® system had to be created. After that the station was pumped down, the force main was dewatered and the pipe was cut for water jet cleaning and CCTV inspection. Due to the heavy incrustations in the host pipe this was performed in a 6 hour window on the first two days, because there was no bypass planned and so the pipe had to be spooled back together in the evening to empty the pump station. After one last cleaning and inspection on the third day, the pre-folded and coiled on a transport reel Kevlar® reinforced composite liner was inserted with speeds up to 15 ft. /min and inflated with 7 psi to bring it back into its round shape. Subsequently the low pressure termination fittings were installed, a pressure test with 60 psi was performed and successfully completed and the pump station was put back into service that evening. During the next morning the pits were closed and the project was successfully accomplished after a total construction time of 4 days and without shutting the pump station down for longer than a daytime window.
Insta-Pipe, Trenchless Pipe Repair
REPAIR SEWERS WITHOUT TRENCHING, WITH SEWER PIPE LINING
With over 25 years of experience, Insta-Pipe Trenchless Pipe Repair can repair sewer and storm lines and repair outside drain pipes with pipe lining services in WA, OR and surrounding areas. Don’t trench when you can take advantage of our pipe lining evaluation and services.
Phone: 360-943-5840 Toll Free: 866-463-9747
855 Trosper Rd SW, 108-204 Olympia, Washington 98512
www.insta-pipe.com
Raedlinger Primus Line, Inc.
112 South Tryon Street, Suite 1130
Charlotte, North Carolina 28284
info@primusline.com www.primusline.com
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.
