Numerical evaluation of the reliability of using single-story substructures to study progressive collapse behaviour of multi-story RC frames

Abstract

Progressive collapse is a global failure for a multi-story building. All stories above the removed column will consequently deform and help redistribute the loads initially withstood by the removed column. However, due to cost and excessive time to be involved, the majority of existing experimental researches regarding progressive collapse rely on single-story beam-column substructures or sub-assemblages. To date, how to use the results from single-story substructures or sub-assemblages to fully or confidently study the behavior of multi-story building is still unclear. Thus, it is imperative to investigate the relationship between the results of single-story substructures and the real behavior of multi-story buildings. Thus, for this purpose, in the present study, a series of planar multi-story reinforced concrete (RC) beam-column substructures were modeled using high-fidelity finite element software LS-DYNA. Firstly, the numerical models were validated by the test results of two three-story planar substructures with different design spans. Secondly, the validated models were explored on various load resistance of each story in the investigated multi-story frame. In addition, the effects of boundary conditions, missing column locations, story numbers on the variation of load resistance were studied in detail using the models.

Effect of loading methods on progressive collapse behavior of RC beam-slab substructures under corner column removal scenario

“…And the yield 125 surface is formed based on three stress invariants J1, J'2, and J'3. Previous studies [19][20][21][22][23] found that 126 erosion criterion based on the maximum principal strain is a suitable way to simulate concrete crushing of concrete after adjustments is shown in Fig. 7.…”

“…tensile membrane action (TMA) in slabs [20,21]. Zhou et al [4] conducted a series of static tests on a one-third scaled RC specimen and two PC specimens using dowel bars and corbel to investigate the load transfer mechanisms of these specimens under a middle column loss.…”

“…And the yield surface is formed based on three stress invariants J1, J'2, and J'3. Previous studies [19][20][21][22][23] found that erosion criterion based on the maximum principal strain is a suitable way to simulate concrete crushing or spalling under both quasi-static and dynamic conditions. However, it could not simulate shear failure well when only the maximum principal strain was adopted for the definition of erosion criterion.…”

“…Therefore, a few adjustments on the elasticity modulus and fracture energy of concrete were made to improve the numerical results. Previous studies [19][20][21]23] suggested that the tensile fracture energy Gft could be reduced to 80% of the default one when it is over predicted. If shear or compressive-based damage is significant, the shear fracture energy Gfs should be set as Gfs = 0.5Gft and Gfc = 50Gft.…”

“…In the past decades, numerous experimental studies [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and numerical simulations [19][20][21][22][23][24][25] have 35 been conducted to investigate the progressive collapse behavior of reinforced concrete (RC) and precast 36 concrete (PC) structures based on the ALP method. Remarkable efforts have been made towards deeper 37 understanding of load transfer mechanisms, such as compressive arch action (CAA) [4][5][6], tensile 38 catenary action (TCA) [7][8][9] developed in beams, and compressive membrane action (CMA) [11,12], 39 tensile membrane action (TMA) in slabs [20,21]. Zhou et al [4] conducted a series of static tests on a 40 one-third scaled RC specimen and two PC specimens using dowel bars and corbel to investigate the load 41 transfer mechanisms of these specimens under a middle column loss.…”