Seismic Isolation of Bridges Using the Principle of Electromagnetic Attraction and Repulsion

Open access

Abstract

This paper presents a new type of seismic isolator that uses the principle of electromagnetic attraction and repulsion, to control the friction force between two electromagnets during earthquakes. The two electromagnets are used in conjunction with a secondary high friction dissipating and damping mechanism composed from a 10mm thick neoprene ring layer and two steel surfaces coated with Si3N4 that are used to dissipate the kinetic energy in the bridge deck at some maximum ground accelerations. The isolator utilizes tri-axial accelerometers embedded in the abutments, high current rechargeable batteries and an automated controlling unit. The presented isolator was developed specifically for a concrete bridge deck with a span of 36 meters and simple supported on two abutments, using time history electromagnetic and structural analyses. The paper presents the advantages of using this active seismic isolation system, compared to classical passive devices and the important results obtained in terms of decreasing internal forces on the substructure elements cross sections together with the reduction of relative displacements between the two electromagnets.

[1]. S. USUBA, R.B. HEIMANN: “Dense Si3N4 Coatings with High Friction Coefficient Deposited by High-Velocity Pulsed Plasma Spraying”, Journal of Thermal Spray Technology, Volume 15(3) September 2006

[2] AMERICAN SOCIETY FOR METALS: „Metals Handbook”, 8th edition, Vol. 1, p792, 1966

[3]. R.A. MATULA: „Electrical Resistivity of Copper, Gold, Palladium and Silver” J. Phys. Chem. Ref. Data, Vol. 8, No. 4, 1979

[4]. U.T.C.B.: „Cod de Proiectare Seismică P100-1”, 2013

[5]. G. RODOLFO SARAGONI, GARY C. HART: „Simulation of Artificial arthquakes”, Earthquake Engineering & Structural Dynamics, Vol. 2, Issue 3, pages 249-267, 1973

[6]. R.W. McCune, C. G. ARMSTRONG, D.J. ROBINSON: „Mixed Dimensional Coupling in Finite Element Models”, Int. Journal for Numerical Methods in Engineering, Vol 49 pp. 725-750, 2000

[7]. DASSAULT SYSTEMES: „Abaqus Analysis User’s Guide”, 2012

[8]. COMPUTER SIMULATION TECHNOLOGY: „CST EM Studio Manual”, 2012

[9]. FARZAD NAEIM, JAMES M. KELLY: „Design of Seismic Isolated Structures–From Theory to practice”, John Wiley&Sons, Inc., N.Y., 1999

[11]. SR-EN 1998-2: „Design of Structures for Earthquake Resistance. Part 2:Bridges”, Eurocodes, 2006

[12]. GARG ANUPAM KUMAR: „Classical Electromagnetism in a Nutshell”, Princeton University Press, 2012

[13]. ASM: „Properties and Selection: Iron, Steels and High Performance Alloys”, ASM International Handbook Committee, USA, 2005

Romanian Journal of Transport Infrastructure

The Journal of Technical University of Civil Engineering Bucharest

Journal Information

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 118 118 35
PDF Downloads 39 39 12