Sep 11, 2017
Custom Robbins Machine finishes on a High Note under Low Cover
The TBM, known an XRE—a Crossover (X) between Rock (R) and EPB (E) TBMs—navigated fault zones, variable ground, low cover, and more to achieve a national record of 57 m (187 ft) in one day as well as maximum rates of 231 m (758 ft) in one week and 702 m (2,303 ft) in one month.
“The XRE has a great advantage as it is designed to work in open and/or closed mode (EPB); allowing it to excavate the tunnel either in soil or in rock. We’ve verified that its performance was very efficient,” said Ing. Juan Alberto Herrera Moro y Castillo, TEP II Section Chief for owner CONAGUA, Mexico’s National Water Commission.
“The benefits of the design are in its exceptional thrust power and in the ease of changing the cutterhead torque. This makes the process much easier should the machine become stuck in difficult ground,” said Alberto Martinez, head of the tunneling department for RECSA.
The XRE machine was launched in August 2015 to bore the 5.8 km (3.6 mi) long wastewater tunnel. The machine was set up in a hard rock configuration and mounted with 20-inch diameter disc cutters. Early in 2016 the TBM hit the first of several contact zones, a 30 m (98.4 ft) wide fault of fractured and blocky rock. While the excavation through the contact zone was slow going, progress picked up again in the more competent andesite rock. After an intermediate breakthrough in March 2016 into an 80 m (262.5 ft) deep shaft followed by inspection and maintenance, the TBM continued on.
While boring in fractured andesite rock in autumn 2016, the TBM encountered a naturally occurring cavern believed to be the result of either a rock fall in a transition zone, or an old, underground lake body that had eroded the rock away. The cavern was estimated at 90 cubic meters (3,200 cubic ft) in size, including about 57 cubic meters (2,010 cubic ft) of unstable floor area. The TBM was stopped and immediate measures were taken to stabilize the ground in front of the machine with polyurethane foam before filling the cavern with a mixture of pea gravel and grout.
“We were able to do this without causing damage to property owned by neighbors in the zone bordering the path of TEP II, or to the road or the urban infrastructure installed in that area,” explained Ing. Francisco Miguel Lopez, Jobsite Manager TEP II for contractor Aldesa.
Now that tunneling is complete, the tunnel will receive a secondary concrete lining of 35 cm (14 in) thickness before going into service. The wastewater tunnel will overhaul the current system in western areas outside of Mexico City and serve to prevent recurrent flooding in Valle Dorado. In particular, the tunnel will benefit the cities of Cuautital Izcalli, Tlalnepantla, and Atizapan de Zaragoza, which altogether are home to 2.1 million inhabitants.
Sep 20, 2017
Lake Geneva offers heating energy for its local communities. By means of heat pumps it can be put to good use. The pipelines installed for transporting the water from the lake consist of ductile iron pipe systems which are perfect ...
Sep 18, 2017
Vertical Pipe Repair offers new CIPP technology
Sep 15, 2017
Projects in Ohio, California, & Vermont will improve performance and save maintenance costs
Sep 13, 2017
HRADIL’s new 300 V New Generation Coaxial Cable 4.0 for sewer relining robots with UV-curing unit permits the use of two independently operated camera systems. The technical solution behind this employs two internal 75 ohm coaxial conductors.
Sep 08, 2017
Salini Impregilo and The Lane Construction Corporation have won a $580-million contract to build the Northeast Boundary Tunnel (NEBT) project in Washington, D.C. The NEBT will be a large, deep sewer tunnel that will increase the capacity of the District’s ...
Sep 06, 2017
In June West Virginia American Water filed an application with the Public Service Commission (PSC) of West Virginia seeking approval of its 2018 infrastructure replacement program and associated Distribution System Improvement Charge (DSIC). The detailed plan includes $29.9 million in ...
Sep 04, 2017
Design-build of a 10 km water transmission pipeline to supply the centre of Ho Chi Minh City, the economic capital of Vietnam / Contract with a value of $69 million (€60 million)
Sep 04, 2017
With the breakthrough of the last two tunnel boring machines into the target pit in Oberhausen-Biefang on June 12, 2017 the tunnel and pipe jacking work for the Emscher sewer has been completed. Over a period of 25 years numerous ...
Sep 01, 2017
AMIBLU headquarters for sustainable water solutions in Klagenfurt
Sep 01, 2017
An energy-positive industrial wastewater treatment system and a company specialising in online sensing and real-time analysis are winners of the 2017 BlueTech Forum Technology Awards. Delegates to the high-level event, held in Dublin on 7 June, selected the winners from ...
Aug 31, 2017
With the new slogan "The Entire World of Underground Infrastructure" UNITRACC welcomes the users with a new and modern design. "Our previous layout did not satisfy the demands of modern mobile devices anymore”, says Dr.-Ing. Robert Stein CEO of visaplan ...
Aug 30, 2017
British Water members now have unlimited access to the Exporters Helpline hosted by the Institute of Export & International Trade (IOE&IT). The telephone support service is just one of the benefits of the trade association’s new membership of the IOE&IT.