Modifications proposed in IS: 13920 (2016) regarding shear wall design following the limit state design philosophy of national and international standards Anasuya Mondal, Santanu Bhanja

In shear walls, the vertical reinforcements being generally uniformly distributed over the section are represented by a continuous steel plate along the length of the wall. Hence, stress blocks for steel in tension and compression with the stress block of concrete are used for solving the equilibrium equations. For checking the safety of the sections which are simultaneously subjected to flexure and axial compression like columns, interaction charts are necessary. The present Indian Standards do not provide such design aids or tools for design of shear walls. Rather some expressions based on simplified assumptions which are not fully conforming to the requirement of LSM of design as per IS: 456 (2000)^[1] are provided. The present work makes a humble effort to overcome the short comings of the design methodology for shear walls as prescribed by IS: 13920 (2016)^[3]. force moment (P-M) interaction diagrams for different grades of structural concrete permitted by IS: 456 (2000)^[1] and four grades of high yield strength deformed (HYSD) steel namely Fe415, Fe500, Fe550, Fe600 have been proposed conforming to the fundamentals of limit state method (LSM) of design as per IS: 456 (2000)^[1]. In addition, P-M interaction charts have been prepared conforming to the requirements of IRC: 112 (2020) ^[29], which is having similar requirements as per EN 1992-1-1 Euro Code: 2. The moment capacities calculated from two sets of P-M interaction charts prepared as per IS: 456 (2000)^[1] and IRC: 112 (2020)^[29] have been compared with the corresponding values obtained from the closed form expressions available in IS: 13920 (2016)[3]. The discrepancies have been clearly highlighted. IS: 456 (2000)^[1] is on the verge of revision whereby significant changes are likely to be introduced. It is most likely that the modified standard will be in line with the RC design provisions of IRC: 112 (2020)^[29], which are in line with international standards. It may be stated that the proposed P-M interaction charts which are more convenient to use than closed form equations, cater not only to the present version of IS: 456 (2000)^[1] but are expected to find useful application for the revised version of the standard also.