Assessment of the effectiveness of cabling system configuration in retrofitting steel-concrete composite buildings

Steel cables have been extensively used in structural design. Even though their most prominent use is in the design of large span cable stayed or prestressed bridges, a variety of applications in buildings has also been realized. In structural design, cables are mainly used as components of (a) prestressed concrete or post-tensioned steel beams, in order to increase their resistance in bending moment, (b) self-centering systems as a means to restore the connected element to its initial position, or (c) bracing systems as an alternative to the typical steel sections. In the past decade, the use of cables has been proposed as a means of creating ties within a structure, in order to increase its collapse resistance. The mechanical behavior of steel cables and its numerical modeling has been extensively investigated experimentally and numerically [1-16]. However, a concise numerical investigation of their effectiveness in retrofitting steel-concrete composite buildings using three-dimensional models has not been performed. In this work, various cable system configurations are assessed with respect to their effectiveness in retrofitting steel-concrete composite buildings. The selected buildings have been found to be deficient regarding their progressive collapse resistance. Cables are installed (a) in various bays of the building, (b) parallel to its structural elements and (c) under the composite slab in order to improve their performance. The effect of post-tensioning on the efficiency of the steel cables is also evaluated. The results yielded illustrate the effectiveness of each configuration.