Porr Bau GmbH and MC-Bauchemie are awarded the innovation prize at tunnel day 2014

The Austrian national committee of the ITA honours new method for the production of earth pulp in tunnel construction.

Vienna, 18 November 2014 - In the course of this year's Tunnel Day on 8 October 2014, the Austrian national committee of the International Tunnelling Association (ITA) has awarded its Innovation Prize to PORR Bau GmbH and MC-Bauchemie Müller GmbH & Co. KG. PORR and MC-Bauchemie con-vinced the independent panel of experts with a novel method for improving the production of earth pulp for earth pressure balance shields, broadening the range of application and significantly reducing the strain on the environment through the addition of conditioning agents. The two companies have already registered this method for patent approval. Also, the method is already being applied - at the construction of the world's most modern sewage water system, the Emscher project.
 
Norbert Hörlein, project manager at PORR Bau and Eugen Kleen, graduate mineralogist and Head of Research and Development at MC-Bauchemie, have jointly developed this method and registered it for the Innovation Prize. They came out on top of a field of fierce competitors and received the award from Prof. Dr. Robert Galler, Head of the Department of Subsurface Engineering at Montanuniversität Leoben (Austria).
 
The panel, consisting of the two Heads of ITA's Austrian national committee and three other main members, praised the far-reaching significance of this innovation in tunnel construction and empha-sised its positive effect on the environment.
 
With the 3rd place at the Tunnel Construction Innovation Prize 2014, PORR, together with the joint-venture Tunnel Albaufstieg, received another pleasing award: The joint-venture Tunnel Albaufstieg (PORR-Hinteregger-Östu/Stettin-Swietelsky), together with Rombold & Gfröhrer GmbH & CO. KG in Ditzingen (Germany), developed a device for reducing the amount of heavy labour in the course of cement stabilisation work - especially for anchoring work inside tunnels. This new cement stabilisation device is currently already in use at project DB new section Wendlingen - Ulm - Albaufstiegtunnel.
 
Starting point and motivation for the innovation
When using earth pressure balance shields in tunnel construction, it is necessary to condition the soil in such a way that a supporting medium can be produced from it. This is generally carried out by adding so-called conditioning agents in the digging chamber of the shield machine. These conditioning agents contain tensides, polymers and other additives. During tunnelling, foam lances, together with said conditioning agents are used to create a foam which is injected into the digging chambers. The foam is conventionally produced "haphazardly" and the process can therefore not be controlled. Thus, foam mixtures with foam bubbles of different sizes and, in turn, earth pulps of varying quality are produced.
 
The innovation
In 2013, PORR Bau GmbH and MC-Bauchemie have, in various laboratory tests, mutually developed a method which allows the production of uniform foam whose characteristics can be controlled. Using pressured air and a gassing line, the medium to be foamed is being put in a foam generator, in which the foam is being created. The innovation is that the special characteristics of the foam generator guarantee the production of a foam which contains a uniform quality of foam bubbles. The number and size of the foam bubbles can be chosen freely and can be adapted to the geological conditions on location.
 
This was subsequently tested in the field: A shield tunnelling machine was equipped with the new foam generators and a special foam creating device - the so-called liquid - developed by MC-Bauchemie. This significantly improves and facilitates the conditioning of the soil. Over several hundred meters of tunnelling, data was collected and evaluated. At constant geological conditions and performance of the tunnelling machine the tests showed a significant reduction in the required amount of foam creation agents - by as much as two thirds compared to the previously used amount. At the same time, the earth pulp produced could be optimally adapted to the soil on location and the desired geo-technical function.
 
"Using this method, we will be able to broaden the range of application of earth pressure balance shields in difficult geological conditions", Norbert Hörlein says and Eugen Kleen adds: "Furthermore, we have found an efficient controlling element for the use of earth pressure balance shields which yields a higher level of biodegradability, is friendlier to the environment and more sustainable due to the fact that less chemicals need to be used."
 
About theTunnel Day Innovation Prize
ITA's (International Tunnelling Association) Austrian national committee with its members ÖGG, ATA, ÖVBB, FSV and ÖIAV stages the the Austrian Tunnel Day every two years in Salzburg, alternating with the Geomechanics Colloqium. They have made it their mission to present Austrian and international engineering concepts in the context of planning and execution of the latest state of technology. Apart from expert speeches, the most innovative contribution in the area of tunnel construction planning and execution is being selected from the pool of submitted projects. The one project that has the most significant practical implications for tunnel construction - also in the context of environmental stress - is picked and honoured with the Innovation Prize by a panel of experts.
 
About PORR
With more than 11,000 staff and a production volume of some EUR 3.4 billion (2013), the PORR group is one of the largest production companies in Austria and one of the leading in Europe. With numerous locations in its home markets of Austria, Germany, Switzerland, Poland and the Czech Republic as well as its international one in Qatar, it is also involved in the realisation of forward-looking construction projects – from residential building construction to complex infrastructure projects in all areas of the construction industry.
 
About MC-Bauchemie
MC-Bauchemie Müller GmbH & Co. KG is one of the leading international manufacturers of products and methods in the area of construction chemistry. With more than 2,000 employees, the group of companies with headquarters in Bottrop operates in more than 40 countries of the world and has stood for game-changing solutions for the modification of concrete and for building maintenance for more than 50 years.