Progressive Collapse Resistance Analysis of Precast Concrete Frames with Infill Walls

The infill wall has a significant influence on the progressive collapse resistance of the precast concrete (PC) frame, and there is no corresponding design method at present. In order to obtain a reliable calculation method for progressive collapse, a numerical and analytical analysis of progressive collapse resistance of PC frames with infill walls was conducted. According to the 3∶1 scale test of PC frames with and without infill walls after removing middle column, and considering the displacement of middle column under the asymmetric distribution of infill walls, a mechanical model based on equivalent strut was established by introducing asymmetry coefficient. Based on the finite element (FE), numerical models of the sub frames with the asymmetric infill walls were established, and displacement-load curves of the middle column were obtained, based on which, the analytical solutions were compared with the test results of bare, double, and single infill wall PC frames, and the results were found in good agreement. A comparison of the calculation results with the recommended values in current codes indicates that the displacement of PC frames under the peak load of catenary is increased when considering the infill wall. The recommended value of the displacement, whose middle column is 0.2 times of the span, is suitable for the bare PC frames, but conservative for the PC frames with infill walls. The results provide a basis for the calculation of the progressive collapse resistance of PC frames with infill walls.