The consolidation and stabilization of the embankment located in the railway line CALATAYUD-VALENCIA, at the section between P.K. 208/100 ANDP.K. 208/200 (within BARRACAS – MASADAS BLANCAS sector) was assigned toAZVI as general contractor. The transit in this line includes trains for the transportation of passengers and freight. The latter, because of their lower frequency of actions, gave rise to sizeable deformations of the track, requiring frequent corrections of ballast thickness, for achieving its adequate levelling. The problem was solved using hydraulic fracture grouting, through sleeve pipes, that was performed by Obras y ProyectosGeotécnicos, S.L. (OPG), specialized firm subcontracted by AZVI. The control of the improvement achieved was effected by obtaining the values of Vs (velocity of shear waves) within the grouted volume of soil, using the cross-hole technique. All the values obtained for Vs werehigher than 400 m/s.

 

It has to be pointed out, that the professional team of OPG in charge of the grouting improvement was the same that, through the use of the same technique had improved, in 2005, the transition zone to the southern abutment of the railway bridge over the Ebro river at Amposta (Tarragona). This job was part of the Spanish contribution to the European SupertrackProyect, and it was carried out simultaneously with the railway traffic (passenger and freighttrains) operating at its normal speed. The passenger trains included the Euromed, which operated at 200 km/h as the track structure (below the ballast layer) and the underlying embankment were being grouted down to a 7 m maximum depth, under the requirement of comfortable operation (movements of rail less than 3 mm in 5 m length).