Behaviour of Base-Isolated Structures with High Initial Isolator Stiffness
Analytical seismic response of multi-story building
supported on base isolation system is investigated under real
earthquake motion. The superstructure is idealized as a shear type
flexible building with lateral degree-of-freedom at each floor. The
force-deformation behaviour of the isolation system is modelled by
the bi-linear behaviour which can be effectively used to model all
isolation systems in practice. The governing equations of motion of
the isolated structural system are derived. The response of the system
is obtained numerically by step-by-method under three real recorded
earthquake motions and pulse motions associated in the near-fault
earthquake motion. The variation of the top floor acceleration, interstory
drift, base shear and bearing displacement of the isolated
building is studied under different initial stiffness of the bi-linear
isolation system. It was observed that the high initial stiffness of the
isolation system excites higher modes in base-isolated structure and
generate floor accelerations and story drift. Such behaviour of the
base-isolated building especially supported on sliding type of
isolation systems can be detrimental to sensitive equipment installed
in the building. On the other hand, the bearing displacement and base
shear found to reduce marginally with the increase of the initial
stiffness of the initial stiffness of the isolation system. Further, the
above behaviour of the base-isolated building was observed for
different parameters of the bearing (i.e. post-yield stiffness and
characteristic strength) and earthquake motions (i.e. real time history
as well as pulse type motion).
[1] Kelly J M. Aseismic base isolation: review and bibliography. Soil
Dynamics and Earthquake Engineering 1986; 13:202-216.
[2] Stanton J, Roeder C. Advantages and limitations of base isolation.
Earthquake Spectra Vol. 7; No. 2; 1991; 301-324.
[3] Jangid RS, Datta TK. Seismic behavior of base isolated building: a stateof-
the-art-review. Structures and Buildings 1995; 110(2):186-203.
[4] Kelly J M. Earthquake-resistant design with rubber, 2nd ed. London:
Springer -Verlag; 1997.
[5] Cheng F Y, Jiang H, and Lou K. SMART STRUCTURES: Innovative
Systems for Seismic Response control, Taylor and Francis, New York,
2008.
[6] Jangid R S and Kelly J M Base isolation for near-fault motions.
Earthquake Engineering and Structural Dynamics, USA, Vol. 30, pp.
691-707, 2001.
[7] Makris N and Chang S P. Effect of damping mechanisms on the
response of seismically isolated structures. Report No. PEER-98/06, UC
Berkeley, Calif. (1998).
[1] Kelly J M. Aseismic base isolation: review and bibliography. Soil
Dynamics and Earthquake Engineering 1986; 13:202-216.
[2] Stanton J, Roeder C. Advantages and limitations of base isolation.
Earthquake Spectra Vol. 7; No. 2; 1991; 301-324.
[3] Jangid RS, Datta TK. Seismic behavior of base isolated building: a stateof-
the-art-review. Structures and Buildings 1995; 110(2):186-203.
[4] Kelly J M. Earthquake-resistant design with rubber, 2nd ed. London:
Springer -Verlag; 1997.
[5] Cheng F Y, Jiang H, and Lou K. SMART STRUCTURES: Innovative
Systems for Seismic Response control, Taylor and Francis, New York,
2008.
[6] Jangid R S and Kelly J M Base isolation for near-fault motions.
Earthquake Engineering and Structural Dynamics, USA, Vol. 30, pp.
691-707, 2001.
[7] Makris N and Chang S P. Effect of damping mechanisms on the
response of seismically isolated structures. Report No. PEER-98/06, UC
Berkeley, Calif. (1998).
@article{"International Journal of Architectural, Civil and Construction Sciences:51219", author = "Ajay Sharma and R.S. Jangid", title = "Behaviour of Base-Isolated Structures with High Initial Isolator Stiffness", abstract = "Analytical seismic response of multi-story building
supported on base isolation system is investigated under real
earthquake motion. The superstructure is idealized as a shear type
flexible building with lateral degree-of-freedom at each floor. The
force-deformation behaviour of the isolation system is modelled by
the bi-linear behaviour which can be effectively used to model all
isolation systems in practice. The governing equations of motion of
the isolated structural system are derived. The response of the system
is obtained numerically by step-by-method under three real recorded
earthquake motions and pulse motions associated in the near-fault
earthquake motion. The variation of the top floor acceleration, interstory
drift, base shear and bearing displacement of the isolated
building is studied under different initial stiffness of the bi-linear
isolation system. It was observed that the high initial stiffness of the
isolation system excites higher modes in base-isolated structure and
generate floor accelerations and story drift. Such behaviour of the
base-isolated building especially supported on sliding type of
isolation systems can be detrimental to sensitive equipment installed
in the building. On the other hand, the bearing displacement and base
shear found to reduce marginally with the increase of the initial
stiffness of the initial stiffness of the isolation system. Further, the
above behaviour of the base-isolated building was observed for
different parameters of the bearing (i.e. post-yield stiffness and
characteristic strength) and earthquake motions (i.e. real time history
as well as pulse type motion).", keywords = "base isolation, base shear, bi-linear, earthquake,floor accelerations, inter-story drift, multi-story building, pulsemotion, stiffness ratio.", volume = "3", number = "2", pages = "67-6", }