International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online), Volume 6, Issue 4, April (2015), pp. 01-12 © IAEME 1 PUNCHING SHEAR RESISTANCE OF FLAT SLABS WITH OPENING Dr Samal M. Rashied Faculty of Engineering, University of Sulaimani Kurdistan of Iraq ABSTRACT There are numbers of methods have been proposed to evaluate the influence from opening on punching shear resistance in flat slabs in the vicinity of columns. In the present paper, the aims are going to compile this state of review on the evaluation of the predicted punching shear strength. A total of 79 tested slabs without shear reinforcement were selected from literature to study the treatments by these methods. The comparisons from their failure loads comparing to their reference specimens without opening shows that the punching shear resistance is inversely proportional to the opening size, location and distance to the face of the related columns. The predictions by ACI-318 and EC2 are investigated to give unsafe punching shear resistance in most cases. Keywords: Punching Shear Resistance, Opening, Critical Shear Perimeter, Perimeter Reduction, Compressive Strength, Effective Depth. INTRODUCTION The earliest design proposal for slabs with holes near supporting columns seems to be that in Kinnunen and Nylander (1) (1960), which reads “A rough estimate of the effect produced by a hole in a slab at a column can be formed by excluding that portion of the imaginary shell, which is cut through by hole. Then if ‘ o ’ denotes the circumstance of the column and if use is made of the rotation given in Fig.36, we obtain the reduced punching load: o s o P P red / ) ( - = ………………. (a) Where P is the calculated punching load of the slab without hole. Fig.36 is replaced here as Fig.1. As printed in (1) the equation is s s o P P red / ) ( - = which must be an error. INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND TECHNOLOGY (IJCIET) ISSN 0976 – 6308 (Print) ISSN 0976 – 6316(Online) Volume 6, Issue 4, April (2015), pp. 01-12 © IAEME: www.iaeme.com/Ijciet.asp Journal Impact Factor (2015): 9.1215 (Calculated by GISI) www.jifactor.com IJCIET ©IAEME