In this paper, the progressive collapse performance analysis of precast reinforced concrete (RC) structures is performed. A numerical simulation framework for precast RC structures is developed on the basis of the OpenSEES software, where the fiber frame element is used for beam and column type members and Joint2D element is used for the beam-to-column connections. The conjugated material models are then introduced, and a min-max failure criterion is imposed on the original models to reflect the steel fracture and concrete crushing when the structure is undergoing progressive collapse. In addition, to overcome the computational difficulties arisen from progressive collapse behavior, two enhanced nonlinear solutions , that is, the consistent quasi-Newton algorithm and the explicit KRalgorithm, are employed, respectively, for static and dynamic analysis. A 10-storey prototype precast RC structures is designed to verify the developed numerical framework, and the progressive collapse resisting mechanism of the structures is investigated through both static pushdown analysis and dynamic column-removal analysis. Finally, influences of some typical parameters in precast RC structures on their progressive collapse performance are studied.
KEYWORDScolumn removal, nonlinear analysis solution, numerical simulation, precast, progressive collapse, pushdown analysis, reinforce concrete structures
INTRODUCTIONPrecast reinforced concrete (RC) structures are widely used in practical structural engineering due to its various advantages, for example, high efficiency, product quality, and low environmental pollution. Especially, in some developing countries such as China, the government has attached great importance to promote precast RC structural systems in recent years, because there exists a large demand of industrial and civilian buildings in their rapid process of urbanization. Therefore, it is of significant value to study the actual performance of the precast RC structures subjected to external loadings for better understanding the failure mechanism and developing appropriate design methods.In the past three to four decades, most studies on precast RC structures were focused on their seismic performance. The conventional way is to conduct cyclic loading tests [1,2] of the precast beam-to-column connections and/or develop high-fidelity finite element models [3,4] to assess the seismic performance (e.g., failure mode, cyclic behavior, and energy dissipation) of the corresponding precast structures. Nevertheless, as a new concern, progressive collapse performance of structures has attracted more and more attentions, [5][6][7] because the unexpected accidental events, for example, malicious attacks, gas explosion, vehicle impact, and human error, were frequently happening around the world in recent years and caused great loss of human lives and public properties. Although the probability of these extreme events is relatively small, the consequences are unbearable.The most common and effective way to assess the progressive col...