Simulation of the Dynamic Response of Steel Moment Frames following Sudden Column Loss. Experimental Calibration of the Numerical Model and Application

by | Feb 8, 2018 | Journals

Significant research effort has been devoted in recent years to the evaluation of the capacity of steel frame structures to resist progressive collapse after sudden column loss. Due to the complex load-structure interaction and material behaviour, it can be very difficult to evaluate the ultimate capacity of structural components using current analytical methods. Therefore considerable research effort has been directed to experimental testing and sophisticated numerical simulations. Although sudden column loss is a dynamic process, most experimental studies on fullscale or scaled down specimens were performed under quasi-static loads. This paper presents the results of a study devoted to the evaluation of steel frame response following the loss of a column. Advanced numerical models are calibrated using experimental test results and dynamic increase factors are studied. Several full-scale structures are investigated for a sudden column loss scenario.

Seismic Vulnerability Assessment Of “Sion Cathedral” (Switzerland): An Integrated Approach To Detect And Evaluate Local Collapse Mechanisms In Heritage Buildings

by | Oct 11, 2017 | Conferences

Seismic assessment of existing heritage buildings remains a challenging task. There is a high level of complexity and uncertainty compared with the assessment of standard buildings. Heritage masonry churches are usually prone to partial collapses during earthquake due to local loss of stability, and exhibit particular seismic vulnerabilities. An important step in the seismic analysis of heritage masonry buildings is the detection of local mechanisms. The Italian Building Code provides a simplified approach (LV1-churches) to assess the vulnerability of heritage churches evaluating and comparing 28 potential mechanisms. A general index of vulnerability and hierarchy between mechanisms is thereby provided. Verification of safety against local mechanisms can also be carried out using the kinematic approach. This procedure is based on evaluating the horizontal action needed to activate out-of-plane collapse mechanisms. Based on a full-scale study (Sion Cathedral), this paper evaluates the reliability of the “LV1-church” approach and of the kinematic approach through a comparison with the results obtained with a complex 3D model using the Applied Element Method.