Performance Based Earthquake Assessment of an Industrial Silos Structure and Retrofit With Sliding Isolators

Abstract

Abstract. Recent seismic events pointed out the high vulnerability of existing industrial facilities, stressing on safety and high losses inherent to interruption of economic activities and release of environmentally hazardous materials. These structures often have irregular geometry and structural configuration, are subject to aging and corrosion, and are designed without specific performance-based or seismic design criteria. Due to these inherent complexities, retrofit using friction isolators can be a viable and practical solution for performance improvements. This work presents a case study of irregular industrial storage plant structure consisting of a group of six elevated silos resting on a steel frame on one side and connected to a vaulted RC structure on the other. A computational model is built incorporating nonlinearities from the components (braces, beams, columns, etc.) and from the mitigation devices. Retrofit using friction isolators is analyzed and evaluated through linear and nonlinear dynamic analyses under a set of natural ground motions. Results show the effectiveness of the mitigation strategy in terms of performance improvement. 5926

Seismic retrofit design and risk assessment of an irregular thermal power plant building

“…The drift hazards of the original design and Retrofit Design A are close when θ max is less than 0.6%. Assuming that the occurrence of earthquakes follows a Poisson process, [57] the probability of exceeding the designated damage states over t years can be computed by using Equation (5). The results for a period of 50 years are presented in Table 8.…”

“…Seismic damages were observed both in structural and nonstructural components such as column supports, girders, mechanical equipment, piping systems, and storage racks. The resulting consequences ranged from the complete collapse to temporarily shut down and included a high likelihood of triggering uncontrolled fires and possible environmental damage . Electric power system is an essential part in an urban community.…”

“…The resulting consequences ranged from the complete collapse to temporarily shut down and included a high likelihood of triggering uncontrolled fires and possible environmental damage. [5] Electric power system is an essential part in an urban community. Nowadays, the majority of global electricity generation is using fossil fuels.…”

“…The simulation results showed that the base isolations reduced the story drift demands as well as the collapse risk under strong earthquakes. Similarly, Rossi et al introduced friction pendulum isolators at the top of columns of supporting silos, and they found that the use of isolations eliminated the torsional effect and protected steel braces from buckling. In addition, a torsional hysteretic damping device was used into the retrofit design of existing silo structures in studies by Pinkawa et al The conducted incremental dynamic analysis results showed its effectiveness in preventing the global sideway collapse failure mode.…”

Performance-Based Nonlinear Response History Analysis Framework for the "Proindustry" Project Case Studies

“…This would decouple the definition of the action from the evaluation of the response, and render the seismic input not strictly structure-specific. A major drawback of using unscaled GMs is that a higher number of records need to be used.The project focus is on the assessment of the structural behavior [38] and on proposing retrofit solutions [39], and the interest is on capturing the mean response. To achieve this goal at least 7 GMs are needed but, considered the high variation of the selected GMs (Approach n.1) a higher number of GMs is to be preferred, at least 11 GMs.…”