We evaluate the seismic performance of a 3-story historical unreinforced brick masonry (URM type building) in Indonesia using the Japan and the US seismic evaluation methods for existing buildings. The previous seismic evaluations in Indonesia were conducted using seismic design code, in which the latest code was published in 2012. The Japan method consists of the first level screening of JBDPA Standard and the AIJ Standard, while the US method consists of Tier 1 and Tier 2 Special Procedure (Tier 2 SP). They are used since they have been widely applied to brick masonry buildings in both countries.
The target building has the total wall height of 17.2 m, with dimension 76.0 m x 25.8 m (main building) and 29.1 m x 25.8 m (wing buildings). The thickness of the wall varies from 1.04 m in the base floor (BF) to 0.45 m in the second floor (2F). The evaluation shows that 2 of 3 stories in x-direction and all stories in y-direction are failed by the Japan method, and 1 of 3 stories in x direction and 2 of 3 stories in y-direction are failed by the Tier 1 evaluation of the US method. The roof and floor diaphragms are failed to resist lateral forces as given by the Tier 2 SP evaluation. Further evaluations using the AIJ Standard and Tier 1 checklists show that the potential deficiencies are found: vertical proportion, floor area and total width of openings.
We propose to retrofit using steel diaphragms and steel frames to strengthen the building, fiber-reinforced plastic (FRP) for the 1F and 2F piers of exterior walls, and base isolating system. The proposals are not yet analyzed and can be object for future studies. The Japan method and the US method are applicable for the quick assessment of brick masonry buildings in Indonesia. However, for more accurate result, they need to be modified, especially related with material property and construction system requirements.