The cost efficiency by using outriggers in tall buildings

Tall buildings construction is in high demanding worldwide for many reasons such as the rapid growth in population together with limited space and the more requirement of the business activities to be localized in city centers. This need for buildings to be raised in height requires special lateral resisting systems to obey the provisions of the codes regarding deflection and human comfort. Outrigger system is one of these lateral resisting systems which have lately confirmed its efficiency as an economic system and having well structural advantages to tall buildings. However, the position and the number of outriggers are still under considerations. Therefore, this research aims to study the effect of the outrigger location on the building' cost. To satisfy this aim, a 35-story building was studied under both seismic and wind loads. The system of the building was taken as a dual system of steel frames and reinforced-concrete core. Then, outriggers in different positions were applied to the building to check the gain in the structural performance and cost through an optimum design. At the end of this work, it was shown that the outrigger can reduce the cost of the building significantly more than 25%.