Geotechnical Isolation of Pile-Supported Bridge Piers Using Eps Geofoam


Abstract eng:
A novel method for reducing the seismic forces imposed on pile-supported bridge piers, is presented. To this end, a flexible bridge pier founded on a single pile is enhanced by adding an annular zone of soft viscoelastic material, such as EPS geofoam, over the upper portion of the pile. It is shown that the annular zone operates as an isolation mechanism, increasing the fundamental natural period of the system and altering its damping. The problem is treated analytically and a simple, design-oriented analysis procedure is developed. Analytical closed-form solutions are derived for: (a) the overall compliance of the pier-pile-geofoam-soil system by means of a dynamic Winkler model of pile-soil interaction, (b) the fundamental natural period, and (c) the overall damping of the system. Based on a response spectrum method, the inertial forces acting at the pile head are determined. The increase in displacements due to the presence of the geofoam is acknowledged, but not investigated here. The influence of problem parameters such as stiffness, thickness and depth of inclusion are examined.

Contributors:
Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



Record appears in:



 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 2278.:
Download fulltext
PDF

Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)