The Influence of Subsidence Angle to Column Demand-Capacity Diagram of a Multistory Building

Abstract

Earthquake is an unpredictable natural disaster, and land subsidence is one of the followed impacts of this disaster. This occurrence can endanger buildings on the disaster area, especially the columns as the central element in the superstructure. This study aims to discover the influence of the inclination angle resulting from the settlement to the axial-moment interaction ratio of the column in a multistory building. The object of this research was Building E functioning for educational purposes and located in the Special Region of Yogyakarta (DIY), Indonesia, with sandy soil conditions. The numerical analysis was simulated by applying the displacement in all supporting systems linearly corresponding to one side-end of a building. Six typical column types in Building E were sampled for investigation, and six variations of inclined subsidence were simulated. Earthquake response spectrum was loaded in all variations of subsidence angle and simulated. The analysis results revealed that several types of columns in Building E was unable to withstand the force after suffering a slope of 0.04°. At the largest simulated angle, 0.1°, only the interior column around the building could be categorized as safe, while several other column types close to the outer perimeter of the building were in critical condition, and some have exceeded their capacity.