Theoretical investigation of geotechnical seismic isolation of bridge piers on footings and piles

• Main Author: Καρατζιά, Πολυξένη
• Other Authors: Μυλωνάκης, Γεώργιος
• Format: Thesis
• Language: English
• Published: 2017
• Subjects: Dynamic impedance; Geotechnical isolation; Surface footing; Liquefiable soil; 3-Layer soil profile; Pile foundation; Bridge pier; Geofoam; Period elongation; Δυναμική δυσκαμψία; Γεωτεχνική σεισμική μόνωση; Επιφανειακό θεμέλιο; Ρευστοποιήσιμο έδαφος; Τρίστρωτο έδαφος; Πάσσαλος; Βάθρο γέφυρας; Γεωαφρός; Επιμήκυνση περιόδου; 624.252

The objective of this dissertation is to investigate the feasibility of using alternative methods for seismic protection of pile- and spread footing-supported bridge piers, which actually aim at ensuring foundation isolation. The method involves using modern industrial materials (such as geofoam) around the upper part of a pile, for reducing the seismic forces imposed to the system, and exploitation of the existing liquefiable soil layer as a natural base isolation system for structures founded on a shallow foundation. Based on elastodynamic theory, the problem of the pier-pile-geofoam-soil interaction is treated both analytically and numerically. The interaction of the pier-foundation-liquefied soil system is explored via equivalent linear analysis using pertinent values for the liquefied soil.