Medium-rise RC framed apartment buildings with storey ranging from 8-12 are becoming popular in metropolitan areas of India. These are provided with shear walls to improve the lateral load resistance. Frequently, the shear walls are provided with openings for functional requirement. Therefore, in the present work, an analytical study on the effect of openings in shear walls was undertaken. The parameters studied are column shear, moments, deflections, stresses within the shear wall, peak storey shear and base shear. A 3D analysis of the shear wall structure was carried out using the STAAD.Pro 2006 software package.

Many medium-rise apartment buildings are being constructed in India using shear walls to provide resistance to earthquake. These shear walls may have openings for the windows, doors and duct spaces for functional reasons. The number, location and size of the openings affect the behavior of a structure.

Framed structures with shear walls are frequently adopted as the structural system for high-rise buildings. This structural system would also have many openings for the entrance to elevator or staircases, etc. Generally, plane stress elements and beam elements are used to model the shear wall and frames respectively in the analysis of this kind of building using STAAD.Pro 2004, but one can use surface element to model shear wall using STAAD.Pro 2006. The openings may be of large size in the case of function halls, conference halls and movie theaters. The number, location, size and shape of the openings affect the behavior of the structure in the form of deflection and stresses in the members. These openings seriously affect the performance of the building.

Several researchers have studied the behavior of shear walls with openings experimentally and analytically. Kent (1974) proposed a method for the analysis of coupled walls with door openings near the edge of the wall. The method was based on continuous connection technique. Khan and Stafford (1976) developed a simplified method by idealizing the basic structure as an assemblage of analogous plate modulus whose stiffness properties are evaluated from finite element analysis. The idealized structure of an unperforated cantilever wall with equivalent stiffness was analyzed by hand, using engineer's beam theory. The method was found to be suitable for wall-frame structure with height to width ratio greater than two and having more than two vertical bands of openings. Daniel et al. (1986) have tested two one-third scale wall specimens under severe earthquake loads to study the effect of centrally located openings at each floor level. Kobayanshi et al. (1995) have tested 26 wall specimens to study the effect of small openings on the strength and stiffness of shear walls in reactor buildings. Based on the test results, they proposed the method for predicting the shear strength of walls. Johnson (1997) tested different wall configurations containing various openings and one control wall with no openings to determine the ultimate capacity and stiffness of shear walls. Qamaruddin (1998) proposed an approximate method to determine in-plane stiffness of shear walls with openings, in which spandrels are assumed flexible and can translate and rotate under lateral load. The computed in-plane stiffness compares well with the stiffness computed by the elastic finite element method.

Structural Engineering Journal, Shear Walls, Framed Structures, Elastic Finite Element Method, Continuous Connection Techniques, Beam Elements, Plane Stress Elements, Structural Elements, Matrix Condensation Techniques, Medium-rise Apartment Buildings, Functional Requirements.