26-08-2016, 04:00 PM
Abstract
Some of the important causes of damage and collapse in concrete building can be classified under general causes to facilitate analysis. These causes are overstress, bad design, faulty construction, foundation failure, unexpected failure modes and combination of causes. In the present work, a case study of an existing building under construction found around Cairo greater area is presented. Methods of strengthening the existing foundation of the buildings to resist lateral and vertical loads are presented. The building consists of a basement, ground floor, and 11 typical floors. The building has been tilted to one side more than 10%. However, the inclination is due to the fact that the foundation design was incorrect. The thickness of raft was 0.95 meters while the required one should be 1.30 meter. In addition, there is a great eccentricity on the raft due to lake of raft design that makes the stresses on soil reaches 5 kg/cm2 at some areas while the allowable is 1.5 kg/cm2 . The increasing area and thickness as well as strengthening of the existing raft foundation are presented. In addition, new reinforced concrete shear walls inside the building connected to the foundations are chosen for strengthening the existing structure to resist lateral forces.
Some of the important causes of damage and collapse in concrete building can be classified under general causes to facilitate analysis. These causes are overstress, bad design, faulty construction, foundation failure, unexpected failure modes and combination of causes. In the present work, a case study of an existing building under construction found around Cairo greater area is presented. Methods of strengthening the existing foundation of the buildings to resist lateral and vertical loads are presented. The building consists of a basement, ground floor, and 11 typical floors. The building has been tilted to one side more than 10%. However, the inclination is due to the fact that the foundation design was incorrect. The thickness of raft was 0.95 meters while the required one should be 1.30 meter. In addition, there is a great eccentricity on the raft due to lake of raft design that makes the stresses on soil reaches 5 kg/cm2 at some areas while the allowable is 1.5 kg/cm2 . The increasing area and thickness as well as strengthening of the existing raft foundation are presented. In addition, new reinforced concrete shear walls inside the building connected to the foundations are chosen for strengthening the existing structure to resist lateral forces.