EVALUASI PERBANDINGAN PEMBEBANAN GEMPA PADA GEDUNG BERTINGKAT SERTA PENGARUH EFEK P-DELTA TERHADAP STABILITAS STRUKTUR BAJA
Abstract
The standard for earthquake resistance regulations in Indonesia which until now have been used, provide two approaches to analyzing structural responses due to earthquakes, namely static equivalent method and dynamic methods (spectrum response and time history) where static equivalent methods are only specific to relatively simple structures and are not recommended for structures high-rise so that to overcome these limitations requires dynamic analysis. The influence of lateral forces due to earthquakes can also cause large deformations in the structure of high-rise buildings, so that the static load in structures distributed into axial forces in the column will provide additional force effects, namely the influence of non-linear geometry (P-delta effect). For this reason, a study of the comparison of steel structure responses to typical multi-storey buildings with 2D portal models to the lateral earthquake force with static equivalent method and time history and the effect of P-delta effects were analyzed with the help of SAP2000 V14.2.1 program on the stability of steel structures and steel end-plates through variations in the number of levels, namely 7, 9, 10 and 15 levels. From the results of the study, it was concluded that the equivalent static method can be used in the structure model 7 and 9 levels because it gives results greater than the dynamic time history method. However, for the 10 and 15 level structure models, the time history method is recommended because it provides greater results so that it is considered safer. If viewed from the effect of the P-delta effect, the 7-level structure gives great results because the planned distance between columns is relatively far. This causes the distributed load in the column to be quite large so that when the structure is deformed due to lateral forces, the effect of additional forces due to axial forces in the column will experience a considerable increase. The 15-level structure model also provides a large P-delta effect. This is because the axial force in the column which causes the P-delta effect, is based on a large structural load distribution due to the relatively high level of the building. In the 9 and 10 level structure models, the effect of the P-delta effect that occurs is not so dominant that it can be ignored.