As part of the 2026 Structural Maintenance Programme (KBU), several interventions are being carried out on structures located along National Road N21 connecting Martigny and the Great St. Bernard Pass. Following detailed technical assessments, appropriate maintenance measures have been defined to address the specific needs of each structure.

The retaining walls at MS Les Valettes 083, MS Gare Bovernier 090, MS La Fory downstream 3 and MS Rive Haute 261 are being rehabilitated as part of this programme.

The works notably include the repair of existing masonry, the construction of new coping elements, the replacement of kerbs and the reconstruction of restraint systems, as well as improvements to drainage systems. These measures help enhance the durability of the structures while meeting current safety requirements.

The A21 Bridge over the Swiss Federal Railways (SBB/CFF) and the Perche Bridge are also being rehabilitated. The interventions notably include the strengthening of structural components, the treatment of deteriorated areas and improvements to waterproofing. These works also make it possible to improve specific construction details in order to slow down deterioration mechanisms and extend the service life of the bridges.