ABSTRACT
The General Directorate of Roads of the Spanish Ministry of Transports asked the Geotechnical Laboratory of CEDEX for technical assistance for the study of a pathology detected at a section, between stations 12+625 and 12+860, of the Burgos ring highway (BU-30). Just after the inauguration of this highway section in 2016, some longitudinal cracks appeared on the right carriageway. Here, the highway runs on embankment which is contained on its right side by earth reinforced wall that in some sections is founded on a stone wall. The cracks reached a vertical gap of about 5-10 cm and were coincident with the vertical plane where the reinforcement strips of the existing reinforced earth wall ended. To prevent accidents these cracks were fixed several times by sealing, milling, and replacing the pavement, but reappeared shortly after. The evolution of movements has been controlled by topographic procedures and by auscultation devices (inclinometers and sliding deformeters). A terrestrial laser scanner (TSL) has also been used to analyse the wall movements, showing a substantial tilting of the wall face, exceeding 0.5 m at wall crest. From the monitoring results it was inferred that the reinforced earth wall has been tilting at a constant rate of up to 60 mm/year, without tendency to stabilize over time. In this paper the highway pathologies, and the methods to characterize them, are described. The analyses of the probable causes and the recommended remedial actions are also presented.
