Due to the repetitive progressive collapse events, it became necessity to form theories of designs against those cases of loadings. Prestressed reinforced concrete elements become widely used in construction field due to various properties that contribute to enhancing the overall structural stiffness, increasing the loading capacity, and elevating the crack resistance threshold compared to the non-prestressed elements. However, few researches in prestressing members and its capacity towards progressive collapse is covered. According to the Unified Facilities Criteria (UFC) and the General Services Administrations (GSA) guidelines, the pre-stressed precast structure’s assessment under progressive collapse are taken into consideration using approximate solutions for analysis. The UFC stated the types of the structure under progressive collapse assessment regardless of the structural system used. This is a great challenge needs a lot of experimental and numerical testing and validation. In this research, a numerical analysis is carried out for a typical five-story framed prestressed precast reinforced concrete structure subjected to column loss (corner column, edge column and internal column near to the structure’s edge), and designed according to Precast/Prestressed Concrete Institute (PCI) and (ACI 318−14). Non-linear dynamic analysis for the structure was carried out using Extreme Loading for Structures (ELS) software depending on the AEM. The investigation was done on two levels. Total collapse took place in case 1. As a result, the necessity of extending the research to include case (2) is essential for having an overview assessment of this type of structures. Case 2 showed high capability to resist progressive collapse against all column removal scenarios. The results are indicated in terms of; prestressed beam behavior, prestressing cable contribution, and flexure and axial loads’ changes with respect to time. Beam and column rotations are calculated and compared to the UFC limitations to assess its safety towards progressive collapse.
Keywords: Applied Element Method; Precast concrete connections; Progressive collapse analysis; Structural failures; Prestressing
ASI’s Extreme Loading for Structures was used by these researchers to perform their 3D nonlinear dynamic time-history based structural analysis. ELS is capable of modeling complex structures with detailed reinforcement in without the need to smearing or remeshing allowing engineers and researchers to more efficiently model real-world structures.
M. Alanani, M. Ehab, H. Salem (2020). Progressive collapse assessment of precast prestressed reinforced concrete beams using applied element method, Case Studies in Construction Materials, Volume 13, 2020, e00457, ISSN 2214-5095, https://doi.org/10.1016/j.cscm.2020.e00457.