A Comparison of the Design of Special RC Moment Resisting Frames (SMRF) with Intermediate RC Moment Resisting Frames (IMRF) for Office Building

Abstract

In earthquake prone area, seismic risk may affect to residential buildings, office structures, and essential infrastructure systems. Previous investigations have revealed that buildings that have been built according to standard drawing may be inadequate to ensure seismic safety. The objective of this research was to compare the design of Special Moment-Resisting Frames (SMRF) with Intermediate Moment-Resisting Frames (IMRF) for a two-story symmetric RC office building with dimensions of 16.0 meters in width, 45.5 meters in length, and 8.2 meters in height, located in Mae Ai District, Chiang Mai Province. The seismic force was calculated using the equivalent static force method. In the case of IMRFs, the base shear was increased by 40% in accordance with design code recommendations. The results indicate that IMRF exhibited base shear forces and overturning moments approximately 1.6 times greater than those of SMRF, while the maximum lateral displacement of IMRF (93 mm) was 1.3 times greater than SMRF. But SMRF required 33% more longitudinal reinforcement and 36% more transverse reinforcement in columns due to the increase of moment capacity according to strong-column weak-beam concept. Conversely, IMRF necessitated 49% more longitudinal reinforcement in beams. Although the total reinforcement quantities between the two systems were comparable, from the structural stability perspective, SMRF is recommended for seismic design.