Behavior of reinforced concrete structure with foundation on sloping soil due to earthquake load.

Sometimes, in certain conditions, we have to build buildings on contours that have different elevations, such as in hilly areas. The building that is built must also be designed to withstand earthquakes in accordance with the applicable standard, namely SNI 1726 2019. The magnitude of this earthquake load is influenced by several factors, ranging from the gravity load on the building, building risk factors, soil site class, and the structural system used. In addition, the configuration of the building also has a significant influence. This is where the configuration of the building is determined by the architectural design and the existing natural conditions. With the advancement of technology, this research can be assisted by the ETABS application, which can see the behavior of the building model from several angles. The building model is made of 10 floors with a slope of 0, 5, 10, 15, and 20 degrees. From the results, it can be seen that the fundamental period decreased from 2.258 – 2.116 sec in the Y direction, which indicates that the increasing slope of the building causes the column to shorten on one side of the building, which makes the building stiffer on one side. The capital participating mass ratio also decreases for each mode, where the 2 translational and 3 rotational modes are almost interchangeable because the value is<50% which can cause a large torque. The center mass displacement diaphragm on the 6th floor and below exceeds the maximum limit with a max value of 80 mm, with the largest deviation value in the Y direction earthquake on the 4th floor with a value of 109 mm, and the irregular torsion on the ground floor exceeds the limit, especially in the Y direction earthquake, where the largest value of the torsion ratio in the Y direction is up to 1.758; with increasing slope, the value is greater. Frame forces also decreased at M2 and M3, but axial forces remained constant. The value can be reduced because the load will be transferred to the shortest side of the building. [ABSTRACT FROM AUTHOR]