مهندسی عمران شریف (Aug 2019)
بررسی رفتار سیستم دیوار برشی فولادی با ورق نازک با درنظر گرفتن اندرکنش خاک – سازه تحت زلزلههای دور و نزدیک گسل
Abstract
The methods for regulations of the analysis of structures are based on the assumption that the structures are located on a rigid substrate, while the studies demonstrate that the soil effect causes a significant change in the structural response. Apart from the discussion of soilstructure interaction, the nature of near-field and far-field earthquakes is at focus here. Nearfield earthquakes are different from far-field earthquakes in terms of both amplitude and frequency content. In this study, the impact of soil-structure interaction between near-field and far-field earthquakes on the structures whose lateral load-bearing system is the thin steel plate shear wall has been investigated. The models applied in this study include six-, twelve-, and twenty-five-storey structures with the system of thin steel plate shear wall, and there are two types of soft and hard soil beneath these structures which respectively have the properties of soil types 3 and 4 and have been modeled according to Iranian Earthquake Standard No. 2800. To analyze these structures, nonlinear dynamic time history analysis method has been used for seven accelerograms of far-field earthquake and seven accelerograms of near-field earthquake. Analysis of both cases of the fixed base and the base of interaction was carried out, and the results showed that shear-to-weight ratio of the effective cumulative story on soils of harder classes (Type 3), in both near- and far-field earthquakes, inconsiderably changed. However, in softer soil classes (Type 4), in both near- and far-field earthquakes, this ratio decreases. The relative structures of stories displacement (drift) in hard soil classes to soft soil classes have a lower rise, and this problem in soft soil classes can result in further damage to the structures. The results showed that the effect of the behavior of steel-plate shear wall systems with thin sheets in near-field earthquake is proven to be high.
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