EFFECT OF BLAST LOADING ON CFRP-RETROFITTED RC COLUMNS Â A NUMERICAL STUDY

Abstract

THIS STUDY AIMS TO INVESTIGATE THE EFFECT OF BLAST LOADS GENERATED AS A RESULT OF EXPLOSIVE CHARGES ON THE EXISTING EXTERIOR RC CIRCULAR COLUMNS OF A TYPICAL BUILDING IN THE CITY OF RIYADH. A PROCEDURE HAS BEEN DEVELOPED FOR EVALUATING THE DYNAMIC CHARACTERISTICS OF THE CIRCULAR COLUMN WITH AND WITHOUT RETROFITTING. A WIDE RANGE OF PARAMETRIC STUDIES HAVE BEEN PERFORMED AS PART OF THIS INVESTIGATION TO EXAMINE THE EFFECTS OF STAND-OFF DISTANCE, CHARGE WEIGHT AND THE PRESENCE OF CFRP RETROFITTING ON THE LEVEL OF DAMAGE TO THE RC COLUMN. THE NONLINEAR FINITE ELEMENT ANALYSIS WAS CARRIED OUT USING LS-DYNA SOFTWARE WITH EXPLICIT TIME INTEGRATION ALGORITHMS. DIFFERENT CHARGE WEIGHTS OF 100, 200, 500 AND 1000 KG EQUIVALENT WEIGHT OF TNT AT STAND-OFF DISTANCES OF 1, 4 AND 15 M WERE CONSIDERED. RESULTS DESCRIBED IN THIS PAPER INDICATE THAT CFRP STRENGTHENING COULD BE AN EFFECTIVE SOLUTION TO LIMIT THE DAMAGE CAUSED BY MODERATE EXPLOSIONS. THE STAND-OFF DISTANCE WAS FOUND TO PLAY A VERY IMPORTANT ROLE IN MITIGATING THE ADVERSE EFFECTS OF A BLAST. THE RESULTS ALSO INDICATE THAT THE MAXIMUM LATERAL DEFLECTION EXPERIENCED BY THE COLUMN DECREASED EXPONENTIALLY WITH THE INCREASE IN THE STAND-OFF DISTANCE AND ALSO DECREASED FOR THE COLUMNS STRENGTHENED WITH CFRP, COMPARED WITH THE UN-STRENGTHENED COLUMNS.