VMT on the “embedded world”

The building project: a pedestrian tunnel which connects the district Barangaroo with the Wynyard Station – with the aim to shorten the walk to about 6 min. The 180m long tunnel with a width of 9m and a height of 3.5m was excavated with conventional construction methods using a road header. The accurate navigation of the machine has been assured by the VMT Navigation System SLS-Roadheader. After an advance period of about 10 months the breakthrough was announced – finalization of the entire project is scheduled for 2016.

From the beginning the challenge in this project has been and still is the exact monitoring of the directly above town center: stability and functionality of all buildings and infrastructure must be constantly and reliably monitored, since only very small reduction tolerances apply. In addition, all major parameters of the construction process must be recorded and made available in real time for various evaluations. VMT has risen to this challenge with its deformation monitoring system in combination with the information system IRIS and mastered so far. Essential components and functions of the deformation monitoring, which is supervised by a three-member survey team, are:

• Automatic 3D surveillance of buildings, roads and structure with motorized total stations
• Manual geodesic supervision of the reference network, various buildings and structures
• Two automatic hydrostatic level systems with a total of 17 sensors
• Automatic and manual tilt control to buildings and structural components
• Well logging with portable inclinometer along the pit

The recorded measurements and the derived time series are transferred to the web-based information system IRIS. All users depending relevant data of the central database can be accessed browser-based. The information system thus provides a convenient platform for consolidation and presentation of monitoring results from various disciplines. In Wynyard Walk project, these are geodesy and measuring technology. Therefore a customized tool is placed at the disposal of the responsible site managers which provides the necessary information for timely decision process in a convenient and reliable manner.

Our client Wayss & Freytag named a reach of the TBM 6 after the responsible VMT project engineer Nadine Fenrich and rose her to the tunnel patroness of the section “Nadine”.

Of course we are very proud that Wayss & Freytag let us – respectively Nadine bestowed such an honor.

The construction phase of the BA30 “Emscher sewer” is on its last legs. The waste water will derived in closed channels in the future, in order to counteract the further pollution of the river Emscher.

This advance was quite challenging for our navigation system SLS Microtunnelling LT. Due to a sharp S-curve with a radius of 150m and 120m at an advance length of 270m, the conditions were very difficult. In addition, the work has been hampered by the small diameter of 1.6m. The excavation lasted 4 months.

In the U.S. state of Nevada, a machine from Herrenknecht has bored a tunnel for the Las Vegas water supply.  In the process, new world records were set: the high-tech boring machine (Ø7.2 meter) had to withstand water pressure of 15 bar. Las Vegas draws 90% of its water from Lake Mead, the largest reservoir in the country. But its water level is dropping, the existing water intakes are at risk. In order to tap the water deep down in the lake in future, for three years the tunnel boring machine bored its way through extremely adverse ground conditions.

On December 10, 2014, with centimeter accuracy the Herrenknecht Multi-mode TBM reached its target at the bottom of Lake Mead. Within three years it has dug a 4.4 kilometer tunnel under the largest reservoir in the U.S.A

VMT has its share at this success by providing several products on the machine that cared for an advance as accurately and efficiently as possible. Thanks to our proven TUnIS TBM^Laser the usually good breakthrough accuracy could be achieved here, too. During tunneling, our TUnIS Navigation Office and IRIS.tunnelviewer guaranteed uninterrupted provision of engineering and navigation data in real time.

The Las Vegas machine launched in late 2011 from a 180 meter deep shaft at the lakeside. For months it struggled through shattered rock and clay with full hydrostatic pressure caused by water from the lake. In doing so it had to withstand pressures of up to 15 bar, an absolute novelty in mechanized tunnelling. As a comparison: 15 bar is like diving at 150 meters or at a pressure of 15 kg per cm². With a diameter of over 7 meters and a length of 190 meters, immense forces were applied on the machine.

Work on Intake No.3 is due for completion in the summer of 2015. The new extraction tunnel will then take the lake water via Intake No.2 to a drinking water treatment plant, from where it will be supplied to households and businesses.

From 24 – February 26 “embedded world” took place in Nuremberg. At the exhibiton our latest product development , Hades Control Center HCC, which we have developed with our partner Zühlke, could be admired.