Robbins Crossover TBMs in New Territory
Sep 30, 2015
First Rock/EPB TBM in North America represents an Evolution in Design
On August 10, 2015, North America’s first Robbins Crossover TBM was launched for the Túnel Emisor Poniente II (TEP II) Project in Mexico City, a complex wastewater scheme for joint venture contractor ALDESA/PROACON/RECSA. Assembled onsite using OFTA (Onsite First Time Assembly), the 8.7 m (28.5 ft) dual-mode type machine is an XRE TBM, and part of the new Robbins Crossover TBM series.
The XRE TBM is capable of “crossing over” (X) between two modes, rock (R) and EPB (E), and its fine-tuned design represents a new generation of Crossover machines.
Variable ground conditions necessitated the contractor’s choice of a Robbins Crossover TBM. The 5.9 km (3.7 mi) tunnel consists of sections ranging from fairly competent to weathered volcanic rock, soft sands, and clays. While standard TBMs tend to lose efficiency in these kinds of variable conditions, the Crossover TBM is equipped with special design features to tackle the mixed ground.
These field-tested features include a single-direction cutterhead for more efficient excavation in abrasive ground, and multi-speed gearboxes. The specialized gearboxes provide added torque at low RPM in fault zones and soft ground, as well as high RPM for rock boring.
The design of the TEP II machine was based largely on experience from past Robbins projects, in particular the Kargi Kizilirmak Hydroelectric Project in Central Turkey. At Kargi, Robbins supplied a 9.84 m (32.3 ft) diameter Double Shield TBM, based on initial geologic reporting of fractured hard rock. Within 80 m (260 ft) of launch, the geology became substantially more difficult than expected, consisting of blocky rock, sand, clays and water-bearing zones. The machine required multiple bypass tunnels and major modifications before it could resume excavation.
Modifications included a custom-built canopy drill and positioner for enhanced drilling and ground consolidation, gear reducers to adjust torque and RPM to changing ground conditions, and short stroke thrust jacks to double total thrust capabilities. After the modifications, advance rates increased dramatically in the difficult ground and soared to 723 m (2,370 ft) in one month as conditions improved. The modifications proved instrumental to the design of Crossover XRE (Rock/EPB) TBMs, including the TEP II machine.
The contractor at TEP II is confident about the machine’s abilities, which are optimized for hard rock but with many EPB characteristics: “In my opinion, the best part about the design of this TBM is the cutterhead; it is very robust,” said Sebastián Gallego Murillo, TEP II Production Manager for PROACON. He added that the biggest challenge would come near the end of the tunnel drive: “We expect to convert [from hard rock] to EPB mode due to the soils in this area. We will need to change out the cutters and modify the cutterhead.”
The benefits of the project are worth the potential challenges. “This tunnel will reduce flooding in the west and northwest areas of the Valley of Mexico, and increase wastewater capacity. It will benefit three municipalities that are home to 2.1 million people,” said Gallego. Twenty years in the making, the TEP II tunnel will eradicate chronic flooding in the sensitive municipalities of Tlanepantla, Atizapan de Zaragoza and Cuautitlan Izacalli, which have historically been affected with overflows as high as 2 m (6.6 ft) during the rainy season.
The News in Brief
- The 8.7 m (28.5 ft) TBM for Túnel Emisor Poniente II is the first Robbins Crossover TBM to be used in North America.
- The XRE TBM is a Crossover (X) between rock (R) and EPB (E), and includes features of both a hard rock Single Shield machine and an EPB.
- The Robbins XRE was successfully completed using Onsite First Time Assembly (OFTA) at a jobsite in Mexico City.
- The 5.9 km (3.7 mi) tunnel consists of incredibly complex ground conditions, from competent to weathered volcanic rock, clay, and sand.
- The XRE TBM is part of a new generation of Crossover machines, designed with field-inspired features including single-direction cutterheads, multi-speed gearboxes, and improved probe drilling capabilities.
- Túnel Emisor Poniente II will relieve overtaxed wastewater lines in three key municipalities home to 2.1 million people. The areas are prone to wastewater overflows of 2 m (6.6 ft) or more during the region’s rainy season.
Click here, to see a drone footage video of the Crossover TBM assembly and launch ceremony.
More News and Articles
Aug 28, 2024
News
ITpipes Secures $20M to Transform Water Infrastructure Management
ITpipes announced it has secured $20 million in equity financing from Trilogy Search Partners and Miramar Equity Partners.
Known for its trusted and user-friendly platform, ITpipes …
Aug 26, 2024
News
Professor Dr.-Ing. Dietrich Stein
With deep sadness we announce the loss of our founder and partner Prof Dr Dietrich Stein at the age of 85.
Engineers around the globe are thankful for his dedication to the inventions in the fields of sewers, …
Aug 26, 2024
News
PPI Releases New Installation Guide for PE4710 Pipe
PPI’s MAB-11-2024 Covers HDPE Water Pipelines Up to 60-in. Diameter and 10,000-ft Long Pulls
Developed by the Municipal Advisory Board (MAB) – and published with the help of the members of the …
Aug 23, 2024
News
Faster wide-scale leak detection now within reach
Mass deployment of connected leak loggers is being made possible by the latest technology, writes Tony Gwynne, global leakage solutions director, Ovarro
Water companies in England and Wales are …
Aug 21, 2024
News
Kraken awakens customer service potential in water
The innovative customer service platform Kraken has made a successful transfer from energy to water. Ahead of their presentation at UKWIR’s annual conference, Portsmouth Water chief executive …
Aug 19, 2024
News
Predicting the toxicity of chemicals with AI
Researchers at Eawag and the Swiss Data Science Center have trained AI algorithms with a comprehensive ecotoxicological dataset. Now their machine learning models can predict how toxic chemicals are …
Aug 16, 2024
News
Goodbye water loss: Trenchless pipe renewal in Brazil
Pipe renewal in Brazil
How do you stop water loss through leaks in old pipe systems without major environmental impacts and restrictions? The answer: with trenchless technology, or more precisely …
Aug 14, 2024
Article
Impact of high-temperature heat storage on groundwater
In a recently launched project, the aquatic research institute Eawag is investigating how the use of borehole thermal energy storage (BTES) affects the surrounding soil, the groundwater …
Aug 12, 2024
News
Watercare completes East Coast Bays sewer link
Watercare has successfully finished the final connection on the East Coast Bays link sewer at Windsor Park in New Zealand.
Much of the East Coast Bays sewer link was installed using horizontal directional …
Aug 09, 2024
Article
Innovative water solutions for sustainable cities
Cities need to become more sustainable and use their water resources more efficiently. Managing water in local small-scale cycles is one possible solution. A new white paper by Eawag, the University …
Aug 07, 2024
Article
How digital technologies contribute to universal drinking water
Digital water technologies have an important role in ensuring universal access to safe drinking water by 2030, that is according to a new report from the World Health Organisation. …
Aug 05, 2024
News
Knowledge transfer on sustainable water infrastructure in India
India’s fast-growing cities need an efficient infrastructure for water supply and wastewater disposal. A research cooperation, is therefore supporting the development of a sustainable …
Contact
The Robbins Company
Desiree Willis
29100 Hall Street
44139 Solon
United States
Phone:
+1 253 872 4490