THE EXPERIMENTAL STUDY OF COLUMN-PEDESTAL CONNECTIONS PERFORMANCE ON ONE-STORY STANDARDIZED METAL BUILDING WITH COLD-FORMED FRAMED STRUCTURE TO CYCLIC LOADING

• Main Author: Mutiara, Dinan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/36448
• Institution: Institut Teknologi Bandung

There is a new construction product in Indonesia nowadays which is named the one-story standardized metal building with cold formed framed structure. Cold formed structure is a structure which uses cold formed steel structural member as the main structural component (as a main frame). Application of such structure is for industrial building, commercial, residential, public facilities, aircraft hangar, etc. This type of structure will be varietly used in Indonesia due to its various advantages. Since Indonesia has a high seismic vulnerability, the behavior of such structure against earthquake loads must be observed. In order to study the behavior of the one-story standardized metal building with cold formed framed structure against earthquake load, an experimental test was conducted based on escape clause in AS/NZS 4600:2005 Cold-formed Steel Structures (adopted by the Indonesian Government to be SNI 7971:2013 Struktur Baja Canai Dingin). Before the test was conducted, two prototype structures of one-story standardized metal building with cold formed framed structure were designed with different span of columns at a main frame. These prototype structures are planned to be built in Bandung, with soft soil condition, as industrial building. Both prototypes are designed using the dimensions of the column profiles and connections which had been determined by the manufacturer. After both of the prototype structures were stated to be strong to withstand the loads that work on them, the design of the test model of these prototype structures could be started. The test was conducted on the columns and pedestal connections of prototype structures as the test model. The height of the columns taken for the test specimen was half of the prototype structure columns height (single curvature test). This area was selected because the prototype structures had a stiffener between the columns and rafters, so the mechanism of dissipation only possibly existed on the bottom of the columns. The pedestal-column connections which were used were the base cleat and the base cleat washer GRC350 bolted to the columns with high strength bolts (grade 8.8). They were manually tensioned and anchored to the concrete block as a pedestal. Double lip channels were used on the column profiles. There were two specimens which were tested, with the differences in the v dimensions of the column profiles. All dimensions and quality of the specimen components were same as the prototype structures (full-scale test specimens). The test results to quasistatic cyclic load indicated that the general behavior of both test specimens was in accordance with the desired behavior of the cold formed steel special bolted moment frames or CFS-SBMF. Inelastic behavior (dissipation mechanisms) of both test specimens happened through a slip mechanism and bearing (dominant in the second specimen (DC25019)). It also happened through the lifting of the base cleat (dominant in the first specimen (DC15024)). Column conditions remained elastic during the test and there were no cracks in the concrete block as a pedestal. So, the connection was the weakest point (the weakest link) on the specimen. The performances of both test specimens were also good, there was no significant degradation of stiffness and strength, not only in the whole cycle of loading which was given but also in the repeated loading cycle of the same amount. Energy dissipation of both test specimens was good, for it continously increased accompanied by the drift increase; in addition, the cumulative energy dissipation amount was almost same. The first test specimen (DC15024) showed the ductility values of 2.57, and the second specimen (DC25019) showed the ductility values of 3.51 (obtained by equivalent elasto-plastic method). The value of R? (ductility reduction factor) was 4.47 for the first test specimen (DC15024) and 7.95 for the second test specimen (DC25019). In both test specimens, the connections could accommodate a story drift angle of 0.04 radian, even until 0.05 radian. The capacity of the connections did not decrease by more than 20% on the story drift angle of at least 0.04 radian. At the 0.04 radian story drift, the specimens could last up to two full cycles. So, both test specimens met the requirements of AISC 341-10 acceptance criteria in the connections in special moment frame.