As part of the ongoing maintenance programme for the airport two new surface water drainage pipelines are required beneath the airport. Due to the complexities of construction and the high degree of security required at the airport as with all airports in the modern age, it was decided to utilise microtunnelling as the preferred option for the installation of the pipelines.
Joint venture contractor Valentin/Eiffage was appointed to complete the microtunnelling works and elected to use a Herrenknecht AVN microtunnelling machine for the job.
For the Charles de Gaulle Airport project the microtunneller was to install two drives of 2,500 mm in diameter as straight bores over lengths of 630 m and 580 m respectively.
To ensure accuracy of the drives the contractor decided to utilise VMT guidance systems for the drives selecting the SLS-Microtunnelling LT system as the best option. However having had no previous experience of the guidance system VMT provided an engineer to take care of the system installation and carry out all required surveys throughout the first of the two drives which took place between February and July 2017. The second drive was recently started in September 2017.
Whilst the first drive was planned to be a straight line bore, closer investigation of the prevailing conditions and the required location of the drive endpoints showed that the drive would be optimised by the introduction of a shallow curve. So, the VMT engineer on site helped to redesign the bore route with an 18,600 m radius curve which successfully achieved the optimisation of the drive route.
This realignment, the high degree of security at the airport and the prevailing conditions made for a challenging first drive in terms of both operations and access to ensure the safest working conditions for the airport staff and construction crew.
Ultimately the first drive was successfully completed in the required timeframe and the preparation for the second drive is at the time of writing well underway.
Die Intergeo fungierte wieder als sehr gutes Kommunikationsforum, um mit unseren Kunden, Interessenten und Partnern interessante Gespräche zu Projekten und Technologien zu führen.
Auf großes Interesse stießen unsere Systemlösung für die Erfassung, Prozessierung, Auswertung und Visualisierung von Deformationsmessungen (MODUS) sowie unser VMT Daten Management System, das webbasiert Prozessdaten komplexer Infrastruktur-Baumaßnahmenkorreliert analysiert, visulalisiert und in Echtzeit weltweit zur Verfügung stellt.
Weil unser Unternehmen kontinuierlich wächst, wird die Gewinnung gut ausgebildeter, motivierter Mitarbeiter immer bedeutender. Auf einem separaten VMT Recruitment Stand konnten sich angehende Techniker und Ingenieure im direkten Austausch ein Bild über das Unternehmen und unser Produktportfolio machen. Auch dieses Angebot stieß auf großes Interesse.
The WestConnex project has recently reached the first of several milestones that will mark the progress of the project with the breakthrough on first tunnelling section. Running for around 1 km between the Underwood and Concord sites, this first breakthrough is just one of a total of 25 tunnels (excluding xp’s) which are being constructed over four separate jobsites. In total there are some 21 Roadheaders operating that are scheduled to complete a total of 7 km of twin road tunnels with an intricate web of exit ramps.
For this particular tunnel, contractor CBPJHD utilised a Mitsui S200 Roadheader to drive tunnel of 10 to 30 m diameter through very challenging ground conditions.
To date some 70% of the tunnel excavation work is complete, with all such works being due to finish by the end of 2017.
For its part VMT has been required to develop, deliver, commission and support some 57 navigation systems, including both hardware and software, between May 2016 and 2019 across both the project areas mentioned above.
The navigation equipment contracts required VMT to supply:
- TUnIS Navigation equipment for all Roadheaders and Bolters
- TUnIS Navigation Office servers and software for each site office for the collection, analysis and management of machine data.
- Permanent service on site for system commissioning and support, plus training of Surveyors, Site Engineers and Operators.
In terms of performance, the VMT engineers on site agreed that with the newly developed TUnIS Navigation Roadheader software being used for the first time, the project was a real challenge. However, in the event, it was proven that the programmers had completed a great job to deliver the software before the start of tunnelling.
In terms of the new hardware, previous hardware used on Roadheaders had become obsolete, and needed to be updated. The extreme environment in tunnels and the continual vibration of the excavation machines had to be accounted for and again to date all hardware has proven to be most reliable.
Collection of data relating to the excavations and machine movements has risen in demand in recent times and was a vital part of the WestConnex programme. VMT had to firstly collect the machine data from different manufacturers and then develop a way to reliably display the huge amounts of captured data online.
One of the biggest challenges for VMT has been the sheer number of machines on which to install, survey and commission equipment and this was quite an intense operation. Having completed the installation, the second part of the process was to train all the people how to use it. With operators, surveyors, electricians and engineers all involved in some part with maintaining the VMT guidance, this involved more than 100 people that needed to learn the systems from VMT’s engineers.
Commenting on the progress to date VMT Project Engineer, Dan McPhail said:
“As with all underground construction projects there have been difficulties and challenges, but the VMT equipment provided, installed and supported by the onsite team has worked extremely well in the challenging conditions of the WestConnex operations. The team work between our own staff, the contractor and the client has proven to be a major contributing factor to the successes achieved to date.”
The Belchen tunnel runs along the A2, between Basel and Egerkingen in Switzerland and crosses the Juragebirge, a ridge that is interspersed with large amounts of gypsum. This has caused damage to the existing tunnel support structure due to ground swelling.
To alleviate the problem, a rehabilitation programme was developed for the two existing tunnels which date from 1970. To facilitate this work the new Belchen Restructuring Tunnel (STB) has been built as a relief road to minimise traffic restrictions associated with the renovation work on the existing tunnels. The construction process places high demands on the design, procedures, construction and maintenance of the north-south axis, which is important for traffic management.
After preliminary works in 2015, the main tunnel works started in February 2016, using what is to date the largest tunnel boring machine (TBM) ever used in Switzerland. The large diameter tunnelling machine (LDT) was 13.97 m diameter and was required to complete some 3,177 m of tunnel. To add to the complexity of the tunnel, it was required to include a curve of 1,250 m minimum radius and a formwork carriage which was pulled in behind the TBM.
Overall the tunnelling work was a very complex logistical operation inside the tunnel which also included the utilisation of a multi-service vehicle (MSV). All the spoil produced during the tunnelling works was transported from the tunnel via a conveyor belt, supplied by Marti AG, directly to a landfill site located some 1.6 km from the tunnel portal.
Maintenance of the correct tunnel alignment and level was therefore critical to the success of the operation, as was the correct installation of the tunnel lining ring segments. The contractor chose VMT systems to support these aspects of the work with the utilisation of TUnIS Navigation TBM Laser, TUnIS Ring Sequencing, Automatic Tailskin Clearance Measurement System SLuM Ultra which enhances the ring build process by measuring the ring position relative to tailskin axis of the TBM with millimetre-accuracy, TUnIS Navigation Office for the monitoring of the tunnel progress and IRIS.tunnel with a local server which offers a comprehensive data management and analysis tool for tunnelling machine data that then allows the TBM to be continuously adjusted and optimised to the prevailing geological conditions, all of which made the works compliant with EN 16191 standard.
After commissioning in 2021, the two existing 50 year old tunnels will be refurbished. Subsequently traffic will flow southwards through the renovated tunnel. After completion of the repair work, two tunnel tubes or four lanes will still be available for traffic.
The project is being undertaken by the Federal Roads Authority (ASTRA), Jürg Röthlisberger, the cantonal committees of the cantons of Basel-Landschaft and Solothurn.
The new line will travel some 8½ miles (13.7 km) to the Metro Green Line and will serve the cities of Los Angeles, Inglewood and El Segundo and portions of unincorporated Los Angeles County. The new Metro Rail extension will offer an alternative transportation option to congested roadways and provide significant environmental benefits, economic development and employment opportunities throughout Los Angeles County. The Crenshaw/LAX Project is one of 12 transit projects funded by Measure R, a 0.5 cent sales tax approved by Los Angeles County voters in 2008.
As part of the construction operation tunnelling works were recently completed that comprised the installation of two 18.8 ft (5.7 m) diameter, 5,400 ft (1,646 m) long tubes between Expo Station and Leimart Park, Los Angeles. The tunnelling works were completed by contractor Walsh/Shea Corridor Constructors using a Herrenknecht-manufactured Earth Pressure Balance (EPB) TBM.
The bores in question were both installed with included curves of 1,000 ft (305 m) radius and therefore required specialist navigation techniques to ensure the curves and tunnel alignment were precisely to specification.
This was achieved in conjunction with VMT GmbH, which has a long established reputation in the US tunnelling market, which provided a selection of navigation technology and data management systems that were used to provide navigation during the tunnelling operation.
VMT provided its latest navigation system TUnIS Navigation TBM Laser which comprises a total station and a target unit installed within the TBM shield which determines the current TBM advance position; TUnIS Navigation Office which provides real-time navigation and ring data from one or more TBMs allowing the navigation system to be directly monitored from the site office and TUnIS Ring Sequencing which automatically calculates the optimum ring sequence for tunnel advances that include segmental lining.
Further to this the tunnelling operation also utilised IRIS.tunnel and IRIS.geomonitoring software. IRIS.tunnel offers a comprehensive data management and analysis tool that allows TBM tunnelling to be continuously adjusted and optimised to the prevailing geological conditions. IRIS.geomonitoring is a comprehensive monitoring program which provides geotechnical measurements to monitor the stability of diaphragm walls, drainage measures, etc. at all times. Extensive sensing data from measurements on existing buildings, influenced by tunnelling projects must frequently be taken into account. Increasingly, these measurements are performed automatically, virtually in real time, thereby yielding large data volumes. Results from manual measurements recorded at regular time intervals must also be processed. IRIS.geomonitoring, can efficiently manage and make available this data in an intelligible and user-friendly format to all project participants.
The supplied equipment was required to meet Class 1 Div 2 – special components specifications.
The Crenshaw/LAX tunnels commenced in April 2016 and tunnelling was completed in April 2017 to the project specifications required.