Failure Probability
Bijan SayyafZadeh; Saeedeh Kouhestani; Mahdi Sharifi
Abstract
Today oil, gas and petrochemical plants risk mitigation and management due to various aspects such as energy supply, financial implications, life loss and repairs has become a primary concern. One of the approaches that can be used for risk assessment of such these plants which are composed of different ...
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Today oil, gas and petrochemical plants risk mitigation and management due to various aspects such as energy supply, financial implications, life loss and repairs has become a primary concern. One of the approaches that can be used for risk assessment of such these plants which are composed of different types of equipment and structures that have different responses and consequences is the probabilistic analysis. Flare is a process equipment that is widely used in oil, gas and petrochemical plants and depending on the height and type of lateral stability is categorized into self-supported, guy-supported and derrick-supported. In this article seismic behavior of a derrick-supported flare is investigated using finite element method and incremental dynamic analysis as a case study. For this purpose, various limit states were considered and for each of them a fragility curve is calculated and also presented with statistical parameters. The results showed that in ordinary seismic intensities there is no significant seismic demand on the investigated structure but in the range of rare intensities that can trigger technological disasters, there is probability of failure and consequently escalating the disaster.
Failure Probability
George Uwadiegwu Alaneme; Gregory C. Ezeokpube; Elvis M. Mbadike
Abstract
Building-failure usually results to collapse if not discovered and properly addressed. Building-collapse/failure most times cause loss of properties and lives. A case study of a partially-collapsed one-story building is presented for emphasis with technical-assessment of the actual collapse cause so ...
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Building-failure usually results to collapse if not discovered and properly addressed. Building-collapse/failure most times cause loss of properties and lives. A case study of a partially-collapsed one-story building is presented for emphasis with technical-assessment of the actual collapse cause so as to proffer remedy of the structure. This is achieved through detailed engineering-analysis of the building’s structural-elements and identification of remedial-options. Field-inspection through excavation of the soil to assess the foundation condition, taking soil-samples from the collapsed-building for laboratory study and non-destructive test. From inspection, it was observed that the building construction was not properly supervised and as a result were under-reinforced, which led to excessive cracks and deflection. The soil is classified by AASHTO as A-2-4; maximum-dry-density of 2.15mg/m3 and optimum-moisture-content of 9%. The compressive-strength of the structural elements were measured using the rebound-hammer and a mean compressive-strength of 13N/mm2 was obtained which indicates a low-compressive-strength concrete. Analytical-hierarchical-process is utilized as the multi-criteria decision making method to derive the actual cause of the collapse and from the priority vector 6%, 56%, 26% and 12% was obtained for soil/foundation, under-reinforcement, low-compressive-strength and overloading alternatives respectively. The consistency-ratio was obtained to be 0.065 this showed that the decision-maker’s subjective assessment is consistent. The summary of the failure investigation underscored the importance of ensuring proper supervision and quality control in the construction of framed structures. The remediation measures outlined are engagement of experts to re-design the structure using relevant-codes; then cracking, chiseling, and excavation to re-build the structure with thorough supervision.
Failure Probability
Saran Srikanth Bodda; Abhinav Gupta; BuSeog Ju; Minho Kwon
Abstract
Safety of critical industrial facilities such as Nuclear power plants has gained significant attention against external events in the last decade. Fukushima Daiichi nuclear power station disaster occurred due to flooding of the plant which was caused by the Great East Japan earthquake and the subsequent ...
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Safety of critical industrial facilities such as Nuclear power plants has gained significant attention against external events in the last decade. Fukushima Daiichi nuclear power station disaster occurred due to flooding of the plant which was caused by the Great East Japan earthquake and the subsequent tsunami. In the US, failure of floodwall system during hurricane Katrina caused widespread damage. Floodwalls are essential to mitigate the effects of rising sea-levels due to climate change. Critical industrial facilities are being increasingly protected from the effects of floods through the use of flood protection systems such as floodwalls, dams, and weirs. This paper evaluates the fragilities for failure of a concrete floodwall due to various failure modes under a multi-hazard scenario (flooding and seismic events). Structural failure of the concrete floodwall is characterized by excessive deformation failure mode for seismic loads. The failure modes considered for flooding loads are rigid body failure and foundation failure.
