1. student at Interdisciplinary Doctoral School , Lodz University of Technology , Żeromskiego 116 , Łódź ; Division of Geotechnics and Engineering Structures Department of Concrete Structures Lodz University of Technology , Al. Politechniki 6 , Łódź
2. Division of Geotechnics and Engineering Structures Department of Concrete Structures Lodz University of Technology , Al. Politechniki 6 , Łódź