SEISMIC RESPONSE OF REINFORCED CONCRETE FRAMES ON FLEXIBLE FOUNDATIONS SUBJECTED TO BOTH HORIZONTAL AND VERTICAL GROUND MOTIONS
DOI:
https://doi.org/10.11113/mjce.v24.15835Keywords:
horizontal and vertical accelerations, Shallow foundation, spring couple, Gap, nonlinear.Abstract
This paper investigates the effect of combined horizontal and vertical accelerations on the seismic response of reinforced concrete resting on shallow foundations. Five and nine-storey buildings are considered to represent low- and medium- rise buildings. The building was assumed to be founded on shallow foundation with soil class corresponding to soft soil deposits, The soil of foundation was modeled by an equivalent massless spring coupled with a gap, located at the base of the structure, allowing for the inelastic bearing capacity of the soil and the loss of contact (uplift) of the base from the supporting soil. The accelergrams used in this investigation in the nonlinear range are the horizontal and vertical components of the New Hall earthquake. Although most building codes postulate that SSI generally decreases the force demand of buildings, and increases the deformation demand, it was found that the inclusion of the vertical ground motion with SSI, the horizontal displacement are decreased compared to the case with only the horizontal component.References
Allotey NK, El Naggar MH. Analytical moment–rotation curves for rigid foundations based on a Winkler model. Soil Dyn Earthquake Eng 2003;23(5): 367–81.
Applied Technology Council, ATC-40. Seismic evaluation and retrofit of concrete buildings, vols. 1 and 2. California; 1996
Anderson DL. Effect of foundation rocking on the seismic response of shear walls. Can J Civil Eng 2003;30(2):360–5.
Antoniou, S., (1997). “Shear Assessment of R/C Structures under Combined Earthquake Loadingâ€, MSc Dissertation, ESEE, Imperial College.
Chaallal O, Ghlamallah N. Seismic response of flexibly supported coupled shear walls. J Struct Eng 1996;122(10):1187–97.
Chen X, Lai Y. Seismic response of bridge piers on elasto-plastic Winkler foundation allowed to uplift. J Sound Vib 2003;266(5):957–65
Collier, C.J. and Elnashai, A.S., (2001). “A Procedure for Combining Vertical and Horizontal Seismic Action Effectsâ€, Journal of Earthquake Engineering, Vol. 5 (4), 521-539.
Computers and Structures Inc; 2002.RPA 2003, Réglement Para-Sismique Algérien, DTR, 2003.
CSI. SAP2000 V-14. Integrated finite element analysis and design of structures basic analysis
reference manual. Berkeley (CA, USA)
Clough, R.W, (1966), „„The Effect of Stiffness Degradation on Earthquake Ductility Requirements,‟‟ Report N66-16, Structural Engineering Laboratory, University of California, Berkeley, California, 1966.
FEMA 256, (2003). “NEHRP Guidelines for the Seismic Rehabilitation of Buildingsâ€, Federal Emergency Management Agency, 1996.
Filiatrault A, Anderson DL, DeVall RH. Effect of weak foundation on the seismic response of core–wall type buildings. Can J Civil Eng 1992;19(3): 530–9.
Ghobarah, A. and Elnashai, A.S., (1998) . “Contribution of Vertical Ground Motion to the Damage of RC Buildingsâ€, 11 th European Conference on Earthquake Engineering, Paris.
H. Shakib , A. Fuladgar (2003). « Effect of vertical component of earthquake on the response of pure-friction base-isolated asymmetric buildingsâ€, Journal of Engineering Structures,
Proceeding of ELSEVIER, Vol 25 (2003),pp. 1841–1850.
Housner GW. The behavior of inverted pendulum structures during earthquakes. Bull Seismol Soc Am 1963;53:403–17.
Javeed A. Munshi and Satyendra K. Ghosh (1997). †Analyses of seismic performance a code designed reinforced concrete buildingâ€, Journal of Engineering Structures, Proceeding
of ELSEVIER, Vol 20 (1997),pp.606-618.
Mwafy, A.M. and Elnashai, A.S., (2006). “Vulnerability of Code-Compliant RC Buildings under Multi-Axial Earthquake Loadingâ€, 4th International Conference on Earthquake
Engineering, Taipei, Taiwan, Paper No. 115.
Mehmet Inel, Hayri Baytan Ozmen. Effects of plastic hinge properties in nonlinear analysis of reinforced concrete buildings. Engineering Structures 2006 ; 28 : 1494–1502
Newmark, N.M., Blume, J.A. and Kapur, K.K. (1973). “Seismic Design Spectra for Nuclear Power Plantsâ€, Journal of the Power Division, Proceedings of ASCE, Vol. 99, No. PO2, pp. 287–303.
Psycharis IN, Jennings PC. Rocking of slender rigid bodies allowed to uplift. Earthquake Eng Struct Dyn 1984;11:57–76.
Prakash V, Powell GH, Campbell S. Drain–2DX base program description and user guide version 1.10. Structural engineering mechanics and materials report no. UCB/SEMM93-18.
Berkeley: University of California; November 1993.
Prakash V, Powell GH, Campbell S. Drain–3DX base program description and user guide, and element description version 1.10. Structural engineering mechanics and materials report
no. UCB/SEMM-94-07 and 94-08. Berkeley: University of California; August 1994.
RAM International. Perform-2D. West Carlsbad, CA 92008 at http://www.ramint.com.
Song Y, Lee D. Improved two-spring model for foundation uplift analysis. Comput Struct 1993;46(5):791–805.
Wilson, E.L. (1998). Three Dimensional Static and Dynamic Analysis: A physical Approach with emphasis on Earthquake Engineering. 2nd edition. Computer and Structures, Inc.
Berkeley, California.
