Seismic behaviour of infilled and pilotis RC frame structures with beam–column joint degradation effect

Abstract The influence of the exterior joints capacity deterioration on the local and global failure mechanisms of reinforced concrete structures with infills is investigated. Exterior beam–column joints with reduced capacity is the common case for the majority of RC structures designed according to older design standards. Nevertheless in common practise the response of these regions is typically assumed as rigid. A key parameter of this investigation is the inclusion of the joints strength and stiffness degradation in the study of the seismic performance of the structures. In this direction, a special-purpose rotational spring element that incorporates a special behaviour model is employed for the simulation of the exterior joints’ local response. The spring element has been incorporated in a well-established general program for nonlinear static and dynamic analysis. The effectiveness of the used joint element model has been demonstrated in a previous paper through comparisons with experimental data reported in literature. In this paper an attempt is presented for the investigation of the influence of the exterior joint damage on the seismic behaviour of bare and infilled RC frame structures. Two types of masonry infilled structures are considered: (a) infilled frame and (b) infilled frame without infills at the base storey (pilotis frame). A parametrical study of the overall seismic response using push over analyses and step-by-step analyses is performed. Results in terms of interstorey drifts, base shear, failure mode, ductility requirements and joints rotational requirements demonstrate that neglecting the possible local damage of the exterior joints may lead to erroneous conclusions and unsafe design or seismic behaviour evaluation that subsequently may become critical in some cases. Furthermore the influence of exterior joints degradation has been proven of vital importance for the overall behaviour of pilotis frames.

[1]  Salah El-Din E. El-Metwally,et al.  Behaviour of reinforced high-strength concrete beam—column joint. Part II: numerical simulation , 2004 .

[2]  Laura N. Lowes,et al.  Evaluation, calibration, and verification of a reinforced concrete beam-column joint model , 2007 .

[3]  Chris G. Karayannis,et al.  Modelling exterior beam–column joints for seismic analysis of RC frame structures , 2008 .

[4]  Constantin E. Chalioris,et al.  EFFECTIVENESS OF RC BEAM-COLUMN CONNECTION REPAIR USING EPOXY RESIN INJECTIONS , 1998 .

[5]  A. Carr,et al.  Modelling of shear hinge mechanism in poorly detailed RC beam-column joints , 2003 .

[6]  Stefano Pampanin,et al.  RELEVANCE OF BEAM-COLUMN JOINT DAMAGE AND COLLAPSE IN RC FRAME ASSESSMENT , 2002 .

[7]  Ahmed Ghobarah,et al.  Dynamic analysis of reinforced concrete frames including joint shear deformation , 1999 .

[8]  T. Paulay,et al.  Seismic Design of Reinforced Concrete and Masonry Buildings , 1992 .

[9]  Alexander-Dimitrios G. Tsonos,et al.  Performance enhancement of R/C building columns and beam–column joints through shotcrete jacketing , 2010 .

[10]  Amr S. Elnashai,et al.  Advanced Nonlinear Formulation for Reinforced Concrete Beam-Columns , 1994 .

[11]  Amr S. Elnashai,et al.  Application of Adaptive Analysis to Reinforced Concrete Frames , 1994 .

[12]  A. G. Tsonos.  Cyclic Load Behavior of Reinforced Concrete Beam-Column Subassemblages of Modern Structures , 2007 .

[13]  A. G. Tsonos.  Effectiveness of CFRP jackets in post-earthquake and pre-earthquake retrofitting of beam-column subassemblages , 2007 .

[14]  Stefano Pampanin,et al.  Seismic response of gravity-load designed frame systems with masonry infills , 2004 .

[15]  B. Izzuddin,et al.  Nonlinear dynamic analysis of framed structures , 1990 .

[16]  D. J. Kakaletsis,et al.  Experimental Investigation of Infilled Reinforced Concrete Frames with Openings , 2009 .

[17]  P. Bakir.  Seismic resistance and mechanical behaviour of exterior beam-column joints with crossed inclined bars , 2003 .

[18]  Alexander G. Tsonos,et al.  Effectiveness of CFRP-jackets and RC-jackets in post-earthquake and pre-earthquake retrofitting of beam–column subassemblages , 2008 .

[19]  A. Ghobarah,et al.  Modelling of shear deformation and bond slip in reinforced concrete joints , 1999 .

[20]  Myoungsu Shin,et al.  Modeling of cyclic joint shear deformation contributions in RC beam-column connections to overall frame behavior , 2004 .

[21]  Hyo-Gyoung Kwak,et al.  Nonlinear dynamic analysis of RC frames using cyclic moment-curvature relation , 2004 .

[22]  S. Kunnath,et al.  Modeling Inelastic Shear Deformation in RC Beam-Column Joints , 1995 .

[23]  Craig D. Comartin,et al.  Evaluation of Earthquake-Damaged Concrete and Masonry Wall Buildings , 2000 .

[24]  L. Lowes,et al.  Modeling Reinforced-Concrete Beam-Column Joints Subjected to Cyclic Loading , 2003 .

[25]  Rolf Eligehausen,et al.  A new model to simulate joint shear behavior of poorly detailed beam–column connections in RC structures under seismic loads, Part I: Exterior joints , 2011 .