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Hinman E.,Hinman Consulting Engineers Inc. | Patin D.L.,Bradley Arant Boult Cummings LLP
Forensic Engineering 2015: Performance of the Built Environment - Proceedings of the 7th Congress on Forensic Engineering | Year: 2015

The U.S. Department of Defense (DoD) mandates progressive collapse protection for all new military buildings that are three or more stories in height. Detailed information regarding acceptable design approaches are provided in relevant Unified Facility Criteria (UFC) documents. These documents are periodically updated as needed. Initially, when UFC progressive collapse criteria were released post-9/11, the extent of protection was typically limited to the building exterior. In 2009, the extent of protection became more dependent on internal security measures. Specifically, internal areas designated as "∼unsecured' required progressive collapse protection. Because the term "∼unsecured' is not well defined, this requirement can cause cost increases to a project if not resolved at the earliest opportunity. In this paper, a legal dispute concerning the extent of the progressive collapse protection required for a military facility is used as a case study to illustrate the issues that can arise. UFC requirements and documents pertaining to the acceptable methods of progressive collapse and the locations of this protection are outlined. © 2016 ASCE. Source

Marjanishvili S.,Hinman Consulting Engineers Inc. | Dogruel S.,Arup
Safety, Reliability, Risk and Life-Cycle Performance of Structures and Infrastructures - Proceedings of the 11th International Conference on Structural Safety and Reliability, ICOSSAR 2013 | Year: 2013

This paper presents a study to estimate structural robustness by uncertainties. Uncertainties are associated with the structural perturbations, where number and perturbation cases are predicted using evolutionary algorithm. A methodology to estimate uncertainties using Genetic Algorithms (GAs) for time efficient calculations is proposed. Finally, the proposed procedure is presented with an example to determine robustness of eight trusses and to rank them according to their respective robustness. © 2013 Taylor & Francis Group, London. Source

Marjanishvili S.M.,Hinman Consulting Engineers Inc.
10th International Conference on Shock and Impact Loads on Structures 2013 | Year: 2013

The possibility of a local structural failure to propagate into a global collapse of the structural system has fuelled the continued development of improved computational methods to model building behaviour. In spite of these efforts, recent events are bringing the issue of collapse mitigation to the forefront and highlighting the shortcomings of existing design practices. The catastrophic nature of structural collapse dictates the need for more reliable methodologies to quantify the likelihood of structural failures and strategies to minimize potential consequences. Focusing largely on the correlation between building configuration and robustness, this paper investigates the extent to which a given structural system results in volumetric changes in internal member forces resulting from initial system perturbations based on stochastic approach. The conclusions of this investigation highlight structural goodness in geometric terms and rate system robustness and the extent to which desired robustness can be achieved. To demonstrate the proposed approach we study four different moment-frame structural configurations to determine the relative quality of each system's configuration. Finally, recommendations are made as to how to quantify the quality of geometry and structural robustness in terms of uncertainty in the initial conditions defining the collapse event. Source

Carlton A.,Hinman Consulting Engineers Inc. | Li Y.,Michigan Technological University
Structures Congress 2015 - Proceedings of the 2015 Structures Congress | Year: 2015

The objective of this paper is to outline a Performance-Based Engineering (PBE) framework to address the multiple hazards of earthquake and Fire Following Earthquake (FFE). Fire codes in the United States are largely empirical and prescriptive in nature. The reliance on prescriptive requirements makes quantifying sustained damage due to fire difficult. The very nature of fire behavior (ignition, growth, suppression, and spread) is fundamentally difficult to quantify due to the inherent randomness present in each stage of fire development. The study of interactions between earthquake and fire is in its infancy with essentially no available empirical testing results. A generalized PBE framework for earthquake and subsequent FFE is presented along with a comparative hazard probability to performance objective matrix and a table of variables necessary to fully implement the proposed framework. Future research requirements, summary, and discussion throughout are provided to describe the cascaded hazards of earthquake and FFE. Source

Marjanishvili S.M.,Hinman Consulting Engineers Inc.
WIT Transactions on Ecology and the Environment | Year: 2011

The term reliability, resilience, risk and redundancy are often used to convey similar or the same concept in literature. Typically, none of these terms are defined in a computationally rigorous manner. Each of these terms has a unique mathematical meaning. However, resiliency and robustness have the special distinction of being particularly powerful because they are completely threat independent. Although it is possible to design structural systems to resist virtually any threat, it is impossible to design these systems to resist all possible threats. Even if all threats could be defined today, they cannot account for unknown future threats that may occur during the life of the structure. As a result robustness evaluation could be useful in prioritizing buildings and critical infrastructure for the purposes of allocating mitigation dollars potentially allowing for a way to optimize both sustainably and effectively. In this paper, the basic concepts used in probabilistic assessment approaches are described and an argument is made for using robustness and resiliency as the primary means for evaluating, repairing and replacing our structural systems in the 21st century. © 2012 WIT Press. Source

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