Integrated geophysical and building damages study of karst effects in the urban area of Alcalá de Ebro, Spain

Pueyo-Anchuela, Ó; Casas-Sainz, A.M.; Soriano, M.A.; Juan Pocoví, A.; Ipas-Lloréns, J.F.; Ansón-López, D.


Karst hazards caused by sinkhole development in the surroundings of the city of Zaragoza (Central Ebro Basin, Spain) have been an increasingly important research subject related to the vulnerability of man-made constructions. Karstic processes have been active during most of the Quaternary, developing an important record of alluvial karst that represents a serious problem for building projects. Karstic problems have been mitigated in many cases by filling and water-proofing of sinkholes. In this work, a multidisciplinary survey is presented, applied to characterize and analyse karst hazards in Alcalá de Ebro (25 km upstream and to the West of Zaragoza) after a sudden collapse in the main street of the village in 2007. The map of damaged structures, GPR surveys, borehole data and microgravimetry survey demonstrated to be a good methodology to be applied in urban settings with karst hazards. The results obtained show that the increase in the activity of karstic processes may have been caused by concrete injection initially intended to reduce the karst hazards.


karstsinkholekarst hazardurban settinggeophysical prospecting