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.
Industry News, trenchless projects
Hard Rock Machine crosses Finish Line Nearly Five Months Ahead of Schedule
In mid-May 2018 the national-record-setting 7.9 m (26 ft) Robbins Main Beam TBM at the Jilin Lot 3 Tunnel broke through. A formal ceremony followed to commemorate the stellar performance of the tunneling operation and its early completion. “I have participated in this project from the beginning. The project broke through 147 days earlier than scheduled. The project has achieved the fastest monthly advance rate record–1423.5 m/4,670 ft—for 7 to 8 m (23 to 26 ft) diameter TBMs in China. And the machine has reached over 1000 m (3,280 ft) per month for three consecutive months. I am so proud of these achievements,” said Mr. Wu Zhi Yong, Vice Chief Engineer and Jilin Yinsong Project Vice General Manager for contractor Beijing Vibroflotation Engineering Co. Ltd. (BVEC).
The completion of the 24.3 km (15 mi) tunnel nearly five months ahead of schedule is a monumental achievement considering the difficult ground conditions encountered. Rock types ranged from tuff to granite, sandstone, and andesite with multiple fault zones—conditions requiring nearly continuous ground support. Rock strengths varied widely from 35 to 206 MPa UCS (5,100 to 30,000 psi). The contractor cited a number of factors that contributed to the swift advance rates: “It is the stable and reliable performance of the Robbins machine, and the professional technical skills of the service technicians. The Robbins crew coordination, reasonable working progress arrangements and the sophisticated technology all allowed the project to make the fast advance rate,” said Mr. Wu.
The Robbins Main Beam TBM bored through a total of 24 fault zones utilizing a unique combination of steel McNally slats (extruded through pockets in the TBM roof shield to prevent movement of loose rock), wire mesh, and shotcrete. The TBM was specifically designed to tackle the tough conditions. “Under the variable ground conditions, especially weak, soft, and fractured rock, the optimized system and reasonable design of the machine ensured effective tunneling progress. Robbins’ unique gripper system, continuous propel system, hydraulic drives, roof support and stable cutterhead reduced the wear of cutters.The efficient belt conveyor inside the main beam allowed quick muck removal from the cutterhead to the back of the machine, which ensured the good progress of the TBM,” said Mr. Wu.
The Jilin Lot 3 tunnel is part of the Jilin Yinsong Water Supply Project, which at 736.3 km (457.5 mi) is China’s largest scale water diversion project to date. Once operational the water lines will divert the water from Fengman Reservoir at the upper reaches of Di’er Songhua River to central regions of Jilin Province experiencing chronic water shortages. These regions include the cities of Changchun and Siping, eight surrounding counties, and 26 villages and towns under their jurisdiction. The project will optimize water resource distribution, improve regional eco-systems, and ensure better food production and water safety for the people of Jilin Province.
Image 1: The record-setting Robbins TBM broke through nearly five months ahead of schedule on China’s Jilin Lot 3 Tunnel.
Image 2: A formal ceremony revealed the Robbins Main Beam TBM during its final breakthrough in mid-May 2018.
Image 3: The 7.9 m (26 ft) diameter Robbins Main Beam TBM overcame 24 fault zones and difficult variable rock conditions to achieve a national record of 1,423.5 m (4,670 ft) in one month.
Industry News, trenchless projects
Trenchless Technology Center at Louisiana Tech University Awarded Project to Measure Styrene and Other Compounds to Capture Variation in Emissions During Pipe Rehabilitation Using the Cured‐In‐Place Pipe (CIPP) Method
(Marriottsville, Maryland, June 15, 2018) – After a careful and thorough review of multiple responses to a request for proposal to provide a comprehensive evaluation of air emissions from steam-cured cured-in-place pipe (CIPP) installations and potential impacts on workers and the surrounding community, NASSCO today announces their award of the research project to the Trenchless Technology Center (TTC) at Louisiana Tech University.
The project is Phase 2 of a larger study and calls for measurement of styrene and other organic compounds at six CIPP installation sites, representing different pipe diameters (8”, 12”, and larger), and lengths, in order to capture variation in emissions. Measurements will be conducted before, during, and after curing at the termination manhole, as well as various locations in the surrounding outside area and inside nearby buildings. Worker exposure will also be measured via personal exposure monitors. Finally, dispersion modeling will be conducted to estimate compound concentrations at a large number of locations for a wide variety of meteorological conditions. Measured and modeled concentrations will be compared to appropriate health-based action levels to determine if any potential health risks exist for workers or citizens in the surrounding communities.
Phase 1 was a four-month study on the review of published literature pertaining to chemical emissions during CIPP installations using styrene-based resins. The study, completed on April 6, 2018 by researchers at the University of Texas at Arlington (UTA)’s Center for Underground Infrastructure Research and Education (CUIRE), and the Institute for Underground Infrastructure (IKT) in Germany, found that existing studies do not adequately capture worker exposures or levels in the surrounding areas to which workers or citizens may be exposed. The team further determined that spatial variation of concentrations, and variations in concentrations with different meteorological conditions, are not well determined.
Late last year NASSCO formed a workgroup consisting of industry leaders to develop the requests for proposal for both Phase 1 and 2 and to select from the multiple responses to ensure the highest levels of integrity in the final selections. “As the NASTT representative on the workgroup for the CIPP Emission Testing project, I am delighted with the selection of TTC as the most meritorious candidate for this important research,” said Mike Wilmets, NASTT Executive Director. “For nearly 30 years, TTC has contributed novel and significant work to further the advancement of the trenchless industry. This will be an exciting assignment with definitive results and will undoubtedly have a far-reaching impact on worksite safety.”
As NASSCO’s new Executive Director, Sheila Joy shares the critical need to partner with other industry organizations for important initiative such as this. “One of my top priorities is to join forces with associations and organizations such as NASTT, WRc, WEF, NUCA and others so that we may have a unified voice and serve our industry to the best of our ability. We all share the same goal when it comes to the safety of our workers and communities, and this study is a perfect example of how unification will reveal the information we need to make smarter decisions for our industry as a whole.”
For questions or additional information, please contact NASSCO at 410-442-7473 or visit nassco.org.
Industry News, trenchless people, trenchless projects
Robbins XRE completes the First TBM-driven Tunnel in Albania
On May 3, 2018 a 6.2 m (20.3 ft) diameter Robbins Crossover (XRE) TBM broke through into an underground chamber, marking the completion of the first TBM-driven tunnel in Albania. The TBM, operated by contractor Limak, was also the first Crossover machine to operate in Europe, and bored through geology including ophiolite, sandstone, breccia and siltstone flysch.
“The cutterhead and cutters have achieved outstanding performance,” said Engin Gur, TBM Manager for Limak. The TBM achieved rates as high as 648 m (2,126 ft) per month in April 2018, and as much as 37.4 m (122.7 ft) in one day. The Crossover TBM did not encounter high-pressure water and was thus used in hard rock Double Shield mode throughout tunneling.
“The TBM performed very well, as did a Robbins-supplied adit conveyor that operated in a 180-degree continuous curve. It was impressive,” said Max Walker, Robbins Field Service Superintendent. Several field service personnel remained onsite throughout operation of the TBM to provide guidance and trouble-shooting.
The machine was launched in November 2016 following Onsite First Time Assembly (OFTA), which enabled the machine to be initially assembled at the jobsite. The crew ramped up production slowly over the next 230 m (755 ft). “Ground conditions were good and we did very few cutter changes—only 20 cutters were used during the bore,” said Walker. Two-stage grouting was carried out as the TBM bored and lined the tunnel in three 8-hour shifts. “The personnel on this project have created a friendly work environment; they’ve made it enjoyable coming to work each day. They’re good guys to work with,” he added.
While the TBM did not need to be sealed, the unique machine design took into account a predicted high risk of water inflows. The Crossover XRE machine used a belt conveyor and not a screw conveyor for muck removal, so the muck chute needed to be able to be sealed off in the case of an inrush of water. The bulkhead was thus designed with a large sealing gate just above the belt conveyor. These pressure-relieving gates could also be used in a semi-EPB mode: As the pressure built in the cutting chamber, the gate would then be opened by the pressure, and material would spill onto the belt. As the pressure lowered, the gates would then automatically close, again sealing off the chamber. In extreme cases, the gates could be sealed and the probe/grout drills could be used to drill, grout, and seal off water. Additionally, the gripper shoes and inner telescopic shield were designed with inflatable seals to further protect against inrushes of water.
With the breakthrough now complete, grouting will continue behind the TBM segments. No additional lining will be added, and the tunnel is expected to become operational by May 2019.
The 6.7 km (4.2 mi) long Moglicë headrace tunnel is part of the Devoll Hydropower Project, a Build-Own-Operate-Transfer (BOOT) scheme to construct two hydropower plants along the Devoll River, named Moglicë and Banja. The project is owned by the Norwegian power company Statkraft AS. The completed Devoll Hydropower Project will increase Albania’s electricity production by 17% and will have an installed capacity of 242 MW.
Image 1: A 6.2 m (20.3 ft) Robbins Crossover (XRE) TBM broke through at the Moglice Headrace Tunnel in Devoll, Albania on May 3, 2018.
Image 2: The breakthrough of the Robbins Crossover (XRE) TBM marks the completion of the first TBM-driven tunnel in Albania.
Image 3: The TBM bored a 6.7 km (4.2 mi) headrace tunnel for the Devoll Hydropower project, advancing at rates of up to 648 m (2,126 ft) per month.
Image 4: Robbins Field Service personnel assisted contractor Limak throughout the project with guidance and trouble-shooting.
trenchless people, trenchless projects
Rutgers University joined the NASTT Student Chapter family in 2016 and has been a valuable addition to our organization. The student members are very active and regularly host guest speakers and go on field trips to area job sites.
Recently, NASTT Board Member, Dennis Walsh, P.E. of Public Service Electric & Gas (PSE&G), gave a presentation on trenchless technology to the members of the Rutgers Student Chapter. Dennis is a Senior Project Manager, Horizontal Directional Drilling for PSE&G in New Jersey. He has designed numerous HDD projects and is a licensed P.E. in five states.
Later, Sergey Wortman-Vayn, P.E., Principal Staff Engineer, Electric & Gas Asset Strategy at PSE&G, took the chapter on a field trip to an HDD site with New Jersey Natural Gas (NJNG) in Bayville, New Jersey.
It is great to see the future of our industry so engaged in learning and networking!
Photo 1: Dr. Nenad Gucunski (left), Rutgers Chapter Adviser and Deptartment Chair with Dennis Walsh (center) and several Rutgers Student Members
Photos 2 & 3: Rutgers Student Memers onsite with NJNG and PSE&G
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 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.
