Tunnelling involves risks associated with ground instability, which are often difficult to predict and which significantly affect the development of the project. Due to these geological instabilities, it is necessary to resort to ground improvement treatments to resolve incidents such as: presence of water pressure, instability of the excavation face, consolidation in fault crossings, advances in karst areas, junctions between the main tunnel and connecting galleries, etc. These treatments are often not included in the design phase, which means that they are not initially planned activities and have a negative impact on the execution time and cost of construction projects.

The implementation of new ground improvement treatment techniques in tunnelling projects presents a significant opportunity to reduce downtime in unplanned events, which in turn improves competitiveness in tenders. The use of more sustainable materials and the reduction in their consumption are essential in this approach, aligning with the current trend towards greener construction practices. In addition, these techniques contribute to the optimisation of processes and systems, thus minimising wasted time and increasing operational efficiency. These advances in ground treatment not only improve the technical and economic feasibility of tunnel projects, but also enhance environmental sustainability and construction safety.

ACCIONA is launching this challenge to identify solutions that offer innovative alternatives in the area of ground improvement treatments in tunnels. The aim of this challenge is to find new ground improvement treatment techniques that improve current treatments from an economic, implementation and sustainability point of view. To this end, any aspect related to the treatment technique can be addressed: design, inspection, materials, equipment, procedures, digitalisation, data management, etc.