First Experiences of a New Generation of Trench Cutter – Contributing to Reducing Carbon Emissions

Diaphragm walls are known as underground structural elements commonly used as retention systems for excavation pits and shafts and permanent foundation walls or elements. It can be anticipated that global urbanization and increasing demands on environmental considerations will need to be accommodated in underground space in the future. These trends show an increasing requirement for diaphragm walling in even more complex conditions, especially in inner-city applications with limited space. For the construction of one of the iconic stations on the Toulouse metro Line C, notable for its exceptional dimensions and the critical scheduling challenges associated with its construction, a new generation of D-wall equipment was launched for the first time in Europe to contribute to the success of this jobsite. Usually, trench cutters are mounted on multi-functional duty-cycle cranes. For those who doesn’t require a multi-functionality but needs equipment that is specially optimized for trench cutting, the extended portfolio will become an alternative. The special design combines proven technology with a vast variety of other useful features as well as the necessary modularity for today’s ever stricter transport requirements. Easier and faster assembling, disassembling and reduced number of transports provide a more cost effective and efficient solution. This contribution and the future possibility to run the system using an electric driven power pack will reduce the local carbon emissions. For that reason, the development can contribute to zero emission sites, which will become demanded more numerously in the future. At first the paper will describe the first finalized projects, e.g., the construction of the 53-meter deep and 1.5-meter-thick walls of La Vache station at the Toulouse metro line C. Furthermore, it will give a general outlook on future developments.