1. Department of Construction, School of Engineering, University of Extremadura, Avenida de la Universidad, s/n, 10003 Cáceres, Spain
2. Department of Civil Engineering, Technical University of Cartagena, Paseo Alfonso XIII 52, 30203 Cartagena, Spain
3. Department of Civil, Environmental and Geomatic Engineering, University College London, Gower Street, London WC1E 6BT, UK