@article { author = {Kalani-Sarokolaee, L. and Khanmohammadi, L. and Navayi Neya, B.}, title = {Effect Of Base Isolation On Seismic Response Of Concrete Elevated Tanks Subjected To Both Translational And Rotational Components Of Far And Near-Field Earthquakes}, journal = {Sharif Journal of Civil Engineering}, volume = {37.2}, number = {3.2}, pages = {59-71}, year = {2021}, publisher = {Sharif University of Technology}, issn = {2676-4768}, eissn = {2676-4776}, doi = {10.24200/j30.2021.57110.2882}, abstract = {Water storage tanks are one of the vital and essential arteries whose immediate operational performance after an earthquake is of special importance and interruptions in their operation can indirectly increase the damage and losses caused by earthquakes. Due to the significant effect of earthquakes on structures located in the vicinity of faults and, also, the unknown effect of the simultaneous transitional and rotational components of these earthquakes, present study investigated the behavior of concrete elevated tanks with central shaft and lead rubber bearing base isolation, under simultaneous excitation of translational and rotational components of near- and far-field earthquakes using nonlinear time history analysis. Base shear force and normal stress of tanks were determined considering dynamic interaction of water and tank. The corresponding rotational component of each translational pair of accelerograms was generated using the classic formulation of the theory of elasticity and wave propagation simultaneously, taking into account the frequency-dependency of wave velocity. To model the base isolator in the present study, an equivalent simplified link and combination model, based on 3D model of reference [32], has been suggested and its performance accuracy has been evaluated. The results of dynamic analysis show that the presence of the base isolator in all the studied conditions causes a reduction of about in base shear and in normal stress of the elevated tanks. Increasing the tank volume will reduce the decreasing effect of the isolator on the normal stress of tanks, but will improve the performance of the seismic isolator in reducing the base shear. Also, increasing the angular acceleration of rotational component of near-field earthquakes weakens by about the decreasing effect of the base isolator on the seismic response of elevated-tanks. Thus, neglecting rotational component of the earthquakes in analysis of tanks located near the faults will magnify the decreasing effect of the base isolator on seismic demands and the poor design of structure. Therefore, use of the isolator to reduce the seismic response in these areas will not be economically justified.}, keywords = {Concrete elevated tanks,Fluid-Structure Interaction,Lead rubber bearing base isolation,Far and near field earthquakes,Translational and rotational components of earthquake}, title_fa = {اثر جداساز پایه بر پاسخ لرزه‌ای مخازن بتنی هوائی تحت اثر همزمان مؤلفه‌های انتقالی و دورانی زلزله‌های حوزه دور و نزدیک گسل}, abstract_fa = {در پژوهش حاضر، رفتار مخازن بتنی هوایی دارای شافت مرکزی و جداساز پایه‌ی لاستیکی هسته‌ی سربی، تحت تحریک همزمان مؤلفه‌های انتقالی و دورانی زلزله‌های حوزه‌های نزدیک و دور از گسل با استفاده از تحلیل تاریخچه‌ی زمانی غیرخطی با احتساب اندرکنش آب و مخزن بررسی شده و نتایج نشان داده است که وجود جداساز پایه در تمامی حالت‌های بررسی شده سبب کاهش حدود ۴۰ تا ۶۰ درصدی برش پایه و ۶۰ تا ۹۰ درصدی تنش بلندشدگی می‌شود. با افزایش حجم مخزن، اثر کاهنده‌ی جداساز در تنش بلندشدگی مخازن کاهش می‌یابد، در حالی که عملکرد جداساز لرزه‌یی در کاهش برش پایه‌ی مخازن هوایی با افزایش حجم مخزن بهبود خواهد یافت. همچنین، افزایش شتاب زاویه‌یی مؤلفه‌ی دورانی زلزله‌های حوزه‌ی نزدیک، سبب تضعیف حدود ۲۰ تا ۳۰ درصدی اثر کاهشی جداساز پایه در پاسخ لرزه‌یی مخازن می‌شود. بنابراین، عدم اعمال مؤلفه‌ی دورانی زلزله در تحلیل مخازن واقع در نواحی نزدیک گسل که پتانسیل مؤلفه‌ی دورانی زلزله‌ها قابل‌توجه است، موجب بزرگ‌نمایی اثر کاهشی جداساز پایه در نتایج می‌شود.}, keywords_fa = {مخازن بتنی هوایی,اندرکنش آب و سازه,جداساز لاستیکی هسته‌ی سربی,زلزله‌های حوزه‌های نزدیک و دور از گسل,مؤلفه‌های انتقالی و دورانی زلزله}, url = {https://sjce.journals.sharif.edu/article_22334.html}, eprint = {https://sjce.journals.sharif.edu/article_22334_4ed73fc79a239a00efc452596cf60176.pdf} }