Abstract. The earthquake resistant steel frame structure is designed to be able to withstand large inelastic deformations in the case of an earthquake. The applicable regulations still allow the use of elastic design methods in the form of pushover analysis and time history analysis evaluation as the basis for the design. The building under consideration consists of six floors with the function as an office building. The location of the building is in Banda Aceh with soft soil conditions. The structural analysis used the help of the Extended Three Dimensional Analysis of Building System Program (ETABS). The method of analysis of steel portal structures used was pushover analysis. Analysis of the given load was static loading based on 1987 PPPURG, and earthquake dynamic loading used a variety of response spectrum procedure analysis based on SNI 03-1726-2012. Structural analysis was assumed to be the strong column weak beam concept. From the results of calculations, it is found that the steel portal structures (with and without braces) designed based on allowable interstory drift limits have met the requirements. The performance level of the steel portal structure without bracing was LS, while the performance level of the steel portal structure using bracing was IO. The largest amount of steel used in terms of weight was found in the case of a portal without braces.

The development of earthquake analysis towards structures is required to prevent damages and loss in buildings due to earthquakes. The base isolation system is a simple design approach for earthquake-resistant buildings to protect the structures and components from the risk of earthquake damages by using the concept of reducing earthquake forces. This research aims to analyze the performance of a general hospital building in Labura Regency area in order to know the safety of the building in terms of period, frequency, base shear force, displacement and earthquake force, used the base isolators and without the base isolators. The method used is response-spectrum dynamic analysis by ETABS v2016 program. From the calculation of structural analysis, the application of base isolation is able to build up the period of the structure, therefore, the maximum acceleration of earthquakes can be reduced at certain period. There is an average increase by 48.21% of the structural period compared to non-isolated base structure, and the frequency that occurs in structures using base isolators is smaller than without base isolators. The friction force obtained is smaller compared to the structures without dampers. Base-isolated building structures observed have bigger displacement than non-base isolated structures. The average rise of the building displacement is 27.14% at x and 2.74% at y directions. In base-isolated structures, earthquake forces are reduced averagely by 57.51% at x and 82.73% at y directions. The analysis of structural performance, General Hospital in Labura Regency is categorized to Immediate Occupancy (IO) in which the building structures are safe with no significant risk of fatalities due to structural failures, there are no any significant damages and the building can be used and functioned/operated again immediately.