trenchless projects
Expansive Metro Project Will Provide Transportation Within Rapidly Developing City
On Tuesday, October 31, 2017, a 6.65 m (21.8 ft) diameter Robbins EPB TBM broke through at Chennai Metro, making this the third tunnel the machine has bored for the project and for contractor Afcons Infrastructure Ltd. The three separate bores for the EPB are part of an increasing trend, as many Robbins EPBs have been used on multiple tunnel drives with good performance. Robbins EPBs are built one third heavier than any other EPB on the market and are designed for 10,000 hours of usable life, making them ideal machines for use over many kilometers. “Robbins is known for designing resilient machines,” said Mr. Gopal Dey, Afcons Senior Manager. “For this project, we needed a machine that was specifically tailored to project conditions from soft clay to mixed ground with rock. Robbins EPB TBMs have unique design features that optimize the machine for the geology.”
After completing its original twin tunnels, the EPB was refurbished in preparation to bore its latest 1.8 km (1.1 mi) section. During refurbishment, the inner seal greasing system was changed from auto to manual mode and the foam nozzle system was modified. These changes optimized the machine for excavation in the highly variable mixed face conditions encountered in the first two tunnels.
The EPB was launched on February 3, earlier this year. According to contractor Afcons, the machine faced a major challenge right out of the gate. “When the TBM came out of the launching shaft, a few rings were erected and then the machine had to cross a live railway track, which meant there would be a possibility of ground settlement,” said Afcons Director, Mr. Manivannan. “At this stage, we had to closely monitor TBM face pressure and advance the machine at a uniform rate to ensure proper primary grouting.” The bore’s geology mainly consisted of clayey sand and about 60 meters (197 ft) of mixed ground.
“We [Afcons] chose this machine for this project due to the underground geology in Chennai, which continuously changes from soil to mixed ground,” said Mr. Dey. “We also liked that Robbins EPB machines are designed with active articulation to allow the machine to turn or steer with ease.” During active articulation, thrust cylinders react evenly against the entire circumference of the tunnel lining, even in a curve—a design that eliminates the problem of tunnel lining deformation. “This feature enabled the machine to negotiate through well-controlled conditions,” added Mr. Manivannan.
With all three tunnels, Robbins Field Service members were on location to assist and support as required. During the course of each bore, Robbins was there to advise Afcons on how best to maneuver through challenging ground and provide instruction for machine operation. The ability of the contractor and manufacturer to work well together, as Robbins and Afcons have throughout their contracts, was critical to the good advance rates. The result was a robust machine that advanced at rates of 80 mm (3 in) per minute in challenging conditions.
This latest tunnel connects multiple stations along the metro line, starting from Washermenpet through to Sir Theagaraya and to Kurukpet. The Chennai Metro Project will provide much needed transportation to a rapidly developing city.
Image 1: On Tuesday, October 31, 2017 a 6.65 m (21.8 ft) Robbins EPB made its third breakthrough at India’s Chennai Metro.
Image 2: Robbins and contractor Afcons celebrate the breakthrough and good performance of the EPB, which achieved rates up to 80 mm (3 in) per minute in mixed ground conditions.
Desiree Willis
Technical Writer
Email: willisd@robbinstbm.com
Direct: 253.872.4490
The Robbins Company
Blog, Industry News
Delivering Outstanding Lifting and Hydraulic Performances
PELLA, Iowa, November 1, 2017 – Vermeer has expanded its compact equipment lineup with the new S925TX mini skid steer, designed to provide impressive lifting performance and the power to conquer the most demanding applications.
With a tip capacity of 2,643 pounds (1,198.8 kg), a rated operating capacity of 925 pounds (419.6 kg) and maximum hinge pin height reach of 84.5 inches (214.6 cm), the radial lift path of the Vermeer S925TX makes easy work of lifting and dumping heavy loads.
The new mini skid steer features a dual auxiliary system which allows the operator to switch between high flow for ground-engaging attachments and low flow for maximum control. It is also equipped with a universal mounting plate that fits a broad range of Vermeer-approved attachments.
“From landscaping and tree care to rental operations, contractors are discovering that Vermeer mini skid steers can increase their daily productivity,” said Jon Kuyers, senior global products manager at Vermeer. “With the S925TX model, we’ve designed a machine that can deliver a higher lifting performance than most other machines in the compact utility loader segment while still maintaining a compact size and impressive hydraulic attachment wielding performance.”
The new Vermeer S925TX mini skid steer is offered in three smooth-running, high-torque, four-cylinder engine options, including a 24.8 hp (18.2 kW) Kubota V1505 diesel engine, a 40 hp (29.8 kW) Kubota WG1605 gas engine and the 35.1 hp (26.2 kW) Kubota V1505 diesel engine offered only for international markets. Contractors can further customize their mini skid steer loader with either 7-inch (17.8 cm) wide tracks that produce 5 psi (.4 bar) of ground pressure or 9-inch (22.9 cm) wide tracks with 4 psi (.3 bar) of ground pressure for even better floatation.
The S925TX mini skid steer has a travel speed of 4.1 mph (6.6 km/h). Like other Vermeer mini skid steers, the S925TX is built with a chariot-style platform for optimum operator comfort, and pilot-operated ground drive to help the user maintain smooth control on the jobsite, as well as in tight areas.
The Vermeer S925TX is backed by a three-year/3000-hour extended limited warranty on the mainframe and loader arms for even more assurance and piece-of-mind on the job.
For more information about the Vermeer S925TX mini skid steer, contact your local Vermeer dealer or visit Vermeer.com.
Industry News, trenchless people
BTE has an immediate opening for a full time professional in its Folsom, CA office. BTE provides stimulating, professional challenges, professional development opportunities, competitive compensation and benefits. BTE is a specialty consulting engineering firm located in Folsom, CA that has spent over 20 years focusing 100% on the design of pipeline projects using trenchless construction methods. Trenchless construction involves installation of utility pipelines using various tunneling and boring methods to limit impacts to sensitive features, such as roads, waterways, and existing structures. The firm specializes in all aspects of design, including feasibility studies, full design services, and construction management services. The candidate will work in the Folsom office and at various project field locations.
Position Description:
Associate engineer
Assist in trenchless design, including writing technical specifications, technical memoranda, preparing and editing drawings, conducting design calculations
Prepare correspondence, participate in meetings with clients
Site meetings and inspection
Up to 25% travel
Required Qualifications:
B.S./M.S. in Civil/Geotechnical/Mechanical Engineering
Proficient with Microsoft Office
Geotechnical engineering experience/competence an important plus
FE/PE a plus
Proficiency in AutoCAD a plus
Compensation Package:
Highly competitive pay, commensurate with degree/experience
Signing bonus/relocation expense reimbursement
Health and dental benefits
Vacation and sick leave, family leave
Profit sharing
Simple IRA employer matching
Strong professional development opportunities
Applications should include the following information:
Cover Letter
Resume
Transcript(s)
Professional Reference(s)
Address application packages to: Dave.Bennett@BennettTrenchless.com
950 Glenn Drive, Suite 115 Folsom, CA 95630
www.BennettTrenchless.com
Industry News, trenchless products
GSSI, the world’s leading manufacturer of ground penetrating radar (GPR) equipment, announces the availability of a new accessory for the industry standard StructureScan Mini XT. The Palm XT is a miniaturized GPR antenna that is designed to greatly enhance the capabilities of the StructureScan™ Mini XT all-in-one GPR concrete inspection system. The handheld Palm XT antenna turns a basic StructureScan Mini XT into an advanced system by giving users unparalleled access in tightly spaced areas and enabling overhead scanning. Designed to withstand challenging construction sites, the Palm XT is an excellent choice for contractors who need to perform concrete scanning and utility locating services.
The 2300 MHz Palm XT antenna offers superior depth penetration and resolution. It features full keypad control via the antenna top that allows for remote control of the user interface. The antenna has seamless software integration and provides users with three data collection modes; standard, cross polarization, and side car. Standard mode requires no special set up, and is ready for plug-and-play operation. Cross polarization mode highlights non-metallic objects, such as PVC, and deemphasizes metallic objects like rebar and wire mesh. Side car mode transitions the survey wheel to the side of the antenna and allows it to fit into smaller spaces.
Rugged, compact, and flexible, StructureScan Mini XT is ideal for locating rebar, conduits, post-tension cables, and voids. The Mini XT can help identify structural elements, including pan deck and concrete cover, and can also provide real time determination of concrete slab thickness. StructureScan Mini XT is the perfect blend of price and performance, and is backed by a two-year warranty. Additional accessories for the StructureScan Mini XT include an extension handle with control button options, and the LineTrac XT. The LineTrac XT adds the ability to detect AC power and induced RF energy present in conduits.
For more information on the Palm XT antenna, visit www.geophysical.com.
About GSSI
Geophysical Survey Systems, Inc. is the world leader in the development, manufacture, and sale of ground penetrating radar (GPR) equipment, primarily for the concrete inspection, utility mapping and locating, road and bridge deck evaluation, geophysics, and archaeology markets. Our equipment is used all over the world to explore the subsurface of the earth and to inspect infrastructure systems non-destructively. GSSI created the first commercial GPR system over 45 years ago and continues to provide the widest range and highest quality GPR equipment available today.
Industry News, trenchless people
Purdue welcomes Dan Liotti of Midwest Mole!
The first NASTT Purdue Student Chapter guest lecture for the 2017-2018 academic year was held on October 19. The guest speaker was Dan Liotti, CEO of Midwest Mole, Inc., who is a Purdue alumnus and the 2015 Trenchless Technology Person of the Year.
The lecture was titled “Trenchless Installation Methods”. The speaker gave a brief review of Auger Boring, Guided Boring, Pipe Jacking, Utility Tunneling and EPB Tunneling. The event also included a discussion with Mr. Liotti about job opportunities in the trenchless market. More than thirty students attended the event.
For more information about NASTT’s Student Chapters, contact NASTT Membership Administrator, Renee Corea.
On Tuesday, October 31, 2017, a 6.65 m (21.8 ft) diameter Robbins EPB TBM broke through at Chennai Metro, making this the third tunnel the machine has bored for the project and for contractor Afcons Infrastructure Ltd. The three separate bores for the EPB are part of an increasing trend, as many Robbins EPBs have been used on multiple tunnel drives with good performance. Robbins EPBs are built one third heavier than any other EPB on the market and are designed for 10,000 hours of usable life, making them ideal machines for use over many kilometers. “Robbins is known for designing resilient machines,” said Mr. Gopal Dey, Afcons Senior Manager. “For this project, we needed a machine that was specifically tailored to project conditions from soft clay to mixed ground with rock. Robbins EPB TBMs have unique design features that optimize the machine for the geology.”
“We [Afcons] chose this machine for this project due to the underground geology in Chennai, which continuously changes from soil to mixed ground,” said Mr. Dey. “We also liked that Robbins EPB machines are designed with active articulation to allow the machine to turn or steer with ease.” During active articulation, thrust cylinders react evenly against the entire circumference of the tunnel lining, even in a curve—a design that eliminates the problem of tunnel lining deformation. “This feature enabled the machine to negotiate through well-controlled conditions,” added Mr. Manivannan.
