الفهرس | Only 14 pages are availabe for public view |
Abstract High-rise buildings have become increasingly important in the new era, and therefore many new developments appear in the structural systems of high-rise buildings with increasing heights around the world. As a result, this study gives light on the systems used in resisting lateral loads, especially the tube systems, which are characterized by their great efficiency in resisting lateral loads, and this system has many categories, which are tube-in-tube, framed, hybrid, and bundled tube. This study is based on evaluating and comparing the seismic characteristics of these systems according to the Egyptian and American codes, as well as studying and calculating the seismic response coefficient (R-reduction factor) represented in the ductility coefficient and the over-strength coefficient through an analytical study of the tube systems and comparing the resulting values with the values used in the international codes. But this study is not limited to that; it also studies the natural frequency and natural period of the building by creating a Fortran program using the direct stiffness method, Dived and Conquer, conjugate gradient method to determine the frequency, mode shape and lateral seismic displacements of the building in an effort to obtain the greatest advantage and benefit from the tube systems and keep up with modern developments in the field of highrise buildings. The study was carried out on two buildings, one framed tube and the other mega tube frame with 15 floors, using software programs, ETABS. The two buildings were designed in accordance with ECP and ACI, and a pushover analysis was carried out using the two programs to determine the response modification factor. in addition, in this study we developing a new solver to perform dynamic analysis for high-rise buildings based on two numerical methods: the divide-and-conquer method and the conjugate gradient method. The Divide and Conquer method were used to calculate all the natural frequencies and mode shapes for tubular-tall buildings, and the displacements due to lateral forces were calculated using the conjugate gradient method. |