Collapse Performance of Three-Dimensional Steel Modular Buildings under Edge Column Loss

Steel modular buildings (SMBs) have gained prominence in the construction industry due to their rapid construction, significant economic benefits, and minimal environmental impact. However, the collapse behavior of SMBs under extreme events remains a critical concern in both engineering and academic fields. To address this issue, a static collapse test is carried out on a three-dimensional modular steel substructure. The responses of the test specimen, including the load-displacement curve, lateral displacements, and strain variations, are analyzed. The experimental results reveal that the load-displacement curve of the specimen exhibits two distinct phases, with the failure mode characterized by the fracture of bolt holes on the beam flanges. The ultimate load of the specimen is about 2.1 times the yield load. The lateral displacement of the specimen remains relatively small before yielding, but increases substantially once the specimen enters yielding phase. Specifically, the lateral displacement of the double-span beam is approximately 2.4 times that of the single-span beam. Furthermore, the influence of secondary beams and boundary primary beams on the collapse performance of SMB is also investigated. The findings indicate that, although these components have a limited impact on the collapse resistance of SMBs, they can significantly reduce the lateral displacement of the columns under large deformations. Moreover, an analytical method for calculating the yield and ultimate loads of SMBs under edge column loss is proposed, offering valuable insights for both design optimization and performance assessment of SMBs in future studies.