پژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Identification of Optimization-Based Probabilistic Scenarios for Seismic Loss Analysis of Qom Lifelinesارائه سناریوهای لرزهای احتمالاتی مبتنی بر بهینهسازی جهت تحلیل خسارت لرزهای شریانهای حیاتی شهر قم114240416FAسید محمد مهدیغفوریدانشکده فنی و مهندسی، دانشگاه قم، قمحمیدزعفرانیپژوهشگاه بین المللی زلزله شناسی و
مهندسی زلزله، تهران0000-0002-4431-9692محمد رضاعدل پروردانشکده فنی و مهندسی، دانشگاه قم، قمJournal Article20181031A fully Monte Carlo Simulation (MCS) that applies to the across region in each step, allows incorporation spatial correlations in each step conditional on the previous step and each simulation must repeat each several times; therefore, the size of computation is concern. The size of computation can be reduced at each step by developing scenarios. The relatively small set of probabilistic scenarios represents the full set obtained from a MCS.<br />In order to consider spatial correlation of individual earthquake scenarios as well as when computational demands are of concern, the optimization-based probabilistic scenario (OPS) method are presented. This method is very appropriate approach that could be applied to a region with high seismicity and effect on the regional loss estimation and regional policy decisions. The OPS method can be important: 1- It is easy for users to understand, 2-The spatial correlation of the ground motion is recorded across the region, 3- It also eliminates concerns about the computation size. This method has a simple concept to record the temporal changes of vulnerability model. We use source–magnitude combination to obtain hazard-consistent annual occurrence probabilities.<br />The OPS method produces a small set of probabilistic seismic scenarios instead of the millions number of scenarios to estimate the seismic hazard and loss estimation of lifelines. This method has a clear framework, includes a step-by-step method for producing earthquake scenarios and ground motion maps. After producing a relatively small set of seismic scenarios, the hazard-consistent annual occurrence probabilities of scenarios are estimated; so that their effect on the across the region approximates that described by given return period maps. For each ground motion map, a set of damage maps are then calculated. Finally, for each damage map, the lifeline system performance is estimated as a function of the system damage. The resulting database of performance levels and associated occurrence probabilities then describe the lifeline risk. Evaluation metrics for computation of the hazard curve errors and spatial correlations errors, introduced by Han and Davidson (2012).<br />We apply the optimization-based probabilistic scenario method to identify the minimum number of scenarios. These scenarios can be used to loss estimation of Qom lifelines. The city of Qom is situated approximately in central Iran. Hazard curves for nine control points have been provided by PSHA, to generate probabilistic scenarios. These nine control points have been located on the study area boundary and equal distance of 12.5 km from each other.<br />Using OPS method, open source solvers and time-independent hazard analysis, has been presented a set of probabilistic seismic scenarios for Qom. First, the output of the conventional Monte Carlo simulation for 1 million years includes 1609087 simulated scenarios. Then scenarios have reduced to 55645 scenarios based on the ‘true’ hazard curve. Finally, the reduced set of earthquake scenarios based on optimization includes three scenarios. The scenarios obtained by the PULP_CBC_CMD and Gurobi 8.0 solvers are the same.<br />Based on the evaluation metrics, the errors are in the appropriate range and there is no unintended bias in the results. The errors are small, 81% of errors in range of ±10%, 91% in range of ±30% and mean hazard curve error is 7.34%. By comparison of the ‘true’ and the reduced set hazard curves in all sites, site 9 has highest average HCEir. For the city of Qom, have been ensured that the difference between the ‘true’ hazard and the reduced set is minimum.<br />It is now possible to extend the probabilistic scenarios for Qom, thus overcoming limitations of the other hazard-consistent probabilistic scenario approaches. In this paper, the hazard is only measured by the PGA, but other terms (such as PGV, SA…) can be considered for the city of Qom.در این مقاله از روش سناریوی لرزهای احتمالاتی مبتنی بر بهینهسازی1 برای تعیین تعداد حداقلی از سناریوهای مناسب که میتواند در تخمین خسارت منطقهای شریانهای حیاتی گستره شهر قم بهکار گرفته شود، استفاده شده است. در روش سناریوی احتمالاتی مبتنی بر بهینهسازی، بهجای میلیونها یا صدها هزار سناریو، مجموعه کوچکی از سناریوهای لرزهای احتمالاتی جهت نشان دادن خطر لرزهای و تحلیل زیرساختهای با توزیع مکانی نظیر شریانهای حیاتی، تولید میشود. پس از تولید مجموعه کوچک سناریوهای لرزهای از پایگاه دادههای چنین رخدادهایی، احتمالات وقوع سالانه سازگار با خطر تخمین زده میشود. این احتمالات بهگونهای است که اثرات ترکیبی آنها روی منطقه مورد نظر همه رخدادهای ممکن بر مبنای روابط باز رخداد مبتنی بر دادههای زلزلهشناسی و زمینشناسی را حفظ میکند. این روش تکرارپذیر و از نظر محاسباتی قابل مدیریت بوده و به سناریوهای زلزله قابلفهم منجر میشود. در نتیجه میتوان سناریوهای مختلف خسارت را جهت تصمیمگیری و سیاستگذاری در خصوص شریانهای حیاتی در نظر گرفت. معیارهای ارزیابی و نیز تطابق منحنی خطر اصلی و منحنی خطر سناریوهای کاهشیافته نشان میدهد که خطاهای سناریوهای تولیدشده برای گستره شهر قم در محدوده مناسبی بوده و انحراف ناخواستهای در نتایج وجود ندارد.https://www.bese.ir/article_240416_47fa769381b2789823c5d5ce0f684512.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Estimation of the Seismicity Potential, Based on Geodetic, Seismic and Geological Moment Rate in the Lut Blockارزیابی توان لرزهخیزی پهنه لوت با مقایسه نرخ گشتاورهای ژئودتیک، لرزهای و زمینشناسی1536240420FAسعیدزارعیدانشگاه بیرجندمحمد مهدیخطیبگروه زمین شناسی، دانشگاه بیرجندمهدیزارعپژوهشگاه بینالمللی زلزله شناسی و مهندسی زلزله، تهران0000-0003-1036-4265سید مرتضیموسویگروه زمین شناسی، دانشگاه بیرجندJournal Article20171015The Lut Zone, with about 900 km length, is in the eastern part of central Iran. The eastern boundary of this zone is specified by the Nehbandan fault and the eastern Flysch of Iran and its western border by the Nayband fault and the Tabas block. East of Iran consists of a series of strike-slip and step-down faults that are fractured-crustal deformable and its evolution is influenced by processes that dominated on the strike-slip shear zones. In other words, the potential energy accumulated in this region is used as a slip along the strike-slip faults of the region, folding and non-slip creep.<br />Earthquake occurrence rates are an essential part of seismic-hazard analysis. Estimate of moment rate is comparatively reckoned as a new method for dealing with tectonic activities rate in different regions and it prepares the way for putting together different methods. There are now three major types of data available to estimate these occurrence rates: Geodetic moment rate, seismic moment rate (on the basis of historical and instrumental earthquake data) and geologic moment rate are estimated for Lut block in east of Iran. Lut block was affected by several large earthquakes in the past causing heavy damage in this region. Each approach has limitations, but in principle they should all yield similar estimates.<br />Firstly, a catalog of historical and instrumental earthquakes was used. Then, while preparing the fault maps of the region, regarding the geometric information of the active faults, the latest information on the geometrical characteristics of the faults has been collected. Finally, geological, seismic and geodetic moment rates for the region were estimated and the results were compared. Depending on the type of deformation and geometry of fault, the study area divided to the five zones: northwestern (zone 1), southwestern (zone 2), north and northeastern (zone 3), southwestern (zone 4) and southern zone (zone 5). Then we compare the value of three types of moment rate in these zones to each other. The most moment rate in the Lut block belongs to geodetic approach (1.2119x1018 Nm/yr) and then seismic moment rate (3.9455x1018 Nm/yr), and finally the least quantity belongs to geologic moment rate (2.4882x1016 Nm/yr).<br />Each of these calculating methods of moment bring from a different perspective that can show different patterns in the style and extent of tectonic activity in the region. Geodetic moment rates include both seismic and non-seismic deformations and cover a highly short time range. Therefore, it is obvious that it shows higher values than the other two methods. The most of seismic moment rate was obtained respectively in Zone 3, 1, 4, 5 and 2. According to seismic map, maximum seismic moment is along Abiz, Dasht-e Bayaz and Tabas Faults. These faults are responsible for large earthquakes in the study area. Maximum geologic moment rate is related to West-Neh, East-Neh, Kahoorak, Abiz and Nosrat-abad Faults. According to values of geological and geodetic moment rates in the southeastern of Lut area and based on the value of the release seismic energy in the north and western part of Lut area, it seems that in the next time, the most of seismic potential and seismic hazard are in the southeastern part of the study area.<br />According to the ratio of seismic to geodetic moment rate can be concluded that the northern part and northwestern part with ratio 2.36 and 0.69 are fast strain areas and south, southwestern and southeastern part with ratio: 0.055, 0.02 and 0.03 are fast strain areas, respectively. Ratio of the geodetic moment rate to the seismic moment rate obtained more than 3.07, which reflects the important role of the interseismic deformation in this area. Ratio of seismic moment rate to geological moment rate is 0.63 %. This value indicates that 0.63 % potential of the faults for seismic energy has been released ant not been released a significant part of the elastic energy in the area.نرخ گشتاور بیانگر میزان انرژی است که در سامانههای دگرریختی صرف میشود و به سه روش ژئودتیکی، لرزهشناسی و زمینشناسی به دست میآید. در این پژوهش پهنهی لوت به پنج ناحیه ساختاری تقسیم شده است. بیشترین مقدار نرخ گشتاور بهدستآمده مربوط به گشتاور ژئودتیک میباشد که برابر با Nm/yr 1019×2118/1 میباشد. نرخ گشتاور لرزهای Nm/yr 1018×9456/3 و در نهایت نرخ گشتاور زمینشناسی نیز معادل Nm/yr1016×4882/2 محاسبه شد. مقایسه نرخ گشتاور ژئودتیک و لرزهای نشان میدهد دگرشکلی بین لرزهای در پهنه لوت 07/3 برابر دگرشکلی لرزهای در این منطقه میباشد. نسبت نرخ گشتاور لرزهای به ژئودتیک در ناحیههای 1 تا 5 بهترتیب برابر با 69/0، 55/0، 36/2، 03/0 و 02/0 برآورد شده است که نشان میدهد واتنش در بخشهای شمالی سریع و در بخشهای جنوبی کند میباشد. نسبت نرخ گشتاور زمینشناسی به لرزهای نشان میدهد 63/0 درصد از کل انرژی پتانسیل موجود در گسلها بهصورت زمینلرزه در طی کاتالوگ زمینلرزهای آزاد شده است و بخش زیادی از انرژی همچنان باقی است و میتواند در آینده آزاد شود. با بررسی نرخهای گشتاور ژئودتیک، لرزهای و زمینشناسی در ناحیههای مختلف پهنه لوت، به نظر میرسد خطرناکترین بخش پهنه لوت از لحاظ پتانسیل لرزهخیزی ناحیه جنوب خاور لوت باشد که منطبق بر سیستم گسل نهبندان از جنوب گسل آبیز تا مرزهای جنوبی پهنهی لوت میباشد.https://www.bese.ir/article_240420_0ccb39826d03ca30d7f1d29f3bf672d7.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Introduction and Structural Study of the Ezedin-Rahjerd Transverse Fault Zone, One of the Seismic Potential Structures in Tafresh Areaمعرفی و بررسی ساختاری پهنه گسلی عرضی- برشی عزالدین- راهجرد؛ یکی از ساختارهای با توان فعالیت در گستره شهرستان تفرش3752240424FAزینبداودیگروه زمینشناسی، دانشکده علوم پایه،
دانشگاه بینالمللی امام خمینی (ره)، قزوینJournal Article20180527Accurate identification of seismic potential is the first step and one of the most important for seismic studies in each region. The study area, located in the middle part of the Urmia-Dokhtar magmatic arc belt, is one of the areas where identify and study of its seismic sources is necessary. In this study, for the first time, the Ezedin-Rahjerd fault system is introduced according to the interpretation of satellite images, field study and tectonic surveys of the area. The Cenozoic (Eocene) volcanic rocks of the Tafresh area, which are covered with Lower and Upper Red Formations have been cut by this N-150 transverse fault of 70 km. This fault system, like other transverse faults such as the Bidhend, Qom-Zefreh and Dehshir-baft faults, has cut volcanic rocks of the magmatic arc belt. Geometry pattern detection of the structures using satellite images and field observations in the area showed that the effect of this fault are observed as the change of the main structure trends such as the reverse faults and fold axes bending and the formation of minor structures with a different trend from the main structures trends of the Urmia-Dokhtar belt. The slicken lines of the fault plane and the right-lateral bending of the main fold axes along the fault zone and the formation of minor structures indicates the right lateral movement of the Ezedin-Rahjerd fault zone.<br />One of the prominent features of the study area is the existence of several parallel dyke sets that are not very distant and sometimes outcropping at a distance of less than 200 m. These dykes with a thickness of about 2-5 m and a length of about 15-20 m with dip of more than 80 degrees are divided into two sets with dominant trends N40-45W and N20-30E. The first set of dykes with N40-45W trending are a semi-deep dolerite and porphyro gabbro diorite that exposed around the Gyan and Lalaein villages and cutting Eocene and older units. Whereas, the second N20-30E trending shallow dikes with combining of hornblende, andesite and basaltic andesite also cuts Miocene volcanic-sedimentary rocks, Qom Formation and Lower Red Formation. Alteration of the second dyke set is significant. The trend, including rocks and tectonic setting of the dykes, show their influence in several stages. These intrusive dikes also show tension fractures, so will assist in structural analysis of the area. In such a right lateral transverse fault zone, development of the tension fractures with N20-30E trend is not unexpected. Therefore, the second shallow N20-30E dyke set are formed in these tension fractures due to the Ezedin-Rahjerd transverse fault activity. While the first set with N40-45W trending that is older than the second one, has been created due to the main structures of the Urmia-Dokhtar magmatic belt.<br />The most important geomorphological feature observed along the Ezedin-Rahjerd fault is the conformity of the Kamar (Tafresh) river as the main river of the area with the fault trend. The Kamar River flows north-south along the Ezedin-Rahjerd fault, passing through the Barezjan, Dadghan, and Ezedin villages, and then reaches the Ghareh-Chai River in Jalaier. Instrumental earthquakes of the area show 2شناسایی دقیق چشمه و پتانسیلهای لرزهای از مهمترین اقدامات لازم و قدم نخست برای مطالعات لرزهخیزی هر منطقه به شمار میرود. گستره مورد مطالعه که در بخش میانی کمان ماگمایی ارومیه دختر واقع است، یکی از مناطقی است که شناسایی و مطالعه دقیق چشمههای لرزهای آن ضروری به نظر میرسید. در این پژوهش با تفسیر تصاویر ماهوارهای و بازدیدهای میدانی و بررسیهای ریختزمینساختی منطقه، برای نخستین بار سامانه گسلی عزالدین- راهجرد با روند 150-N و طول بیش از 70 کیلومتر معرفی میشود. این پهنه گسلی، همروند با گسلههای عرضی- برشی دیگر همچون گسلههای بیدهند، قم- زفره و دهشیربافت، سنگهای آتشفشانی کمان ماگمایی را بریده است. خش لغز گسلی، خمش راستبر روند محور چینهای اصلی در راستای گسله و تشکیل ساختارهای فرعی مرتبط با آن بیانگر حرکت راستبر این گسله است. بررسی زمینریختشناسی و جابهجایی راستبر آبراههها با گسله، بیانگر فعالیت گسله در زمان کواترنری است. انطباق مرکز سطحی زمینلرزهها بر روی این گسله، اهمیت شناسایی و معرفی این پهنه گسلی را در مطالعات لرزهخیزی منطقه نشان میدهد. لذا احتمال وقوع زمینلرزه ویرانگر در اثر فعالیت پهنه گسلی عرضی-برشی عزالدین- راهجرد بهعنوان گسلی که فعالیت کواترنری داشته است، دور از انتظار نیست و ممکن است در خطر لرزهای شهرستان تفرش و مناطق همجوار نقش تعیینکننده داشته باشد.https://www.bese.ir/article_240424_d88de1a2adab52bac28d95c12bcb81ff.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Evaluation of Shear-Wave Velocity in Granular Soil Using Bender Element and Resonant Columnارزیابی سرعت موج برشی در خاکهای دانهای با استفاده از المانهای خمشی و ستون تشدید5369240425FAمیثمبیاتگروه مهندسی عمران، واحد نجفآباد، دانشگاه آزاد اسلامی، نجفآباد0000-0001-5525-5199عباسقلندرزادهگروه مهندسی عمران، دانشکده فنی، دانشگاه تهران، تهران0000-0001-9939-7842Journal Article20190101Shear wave velocity, Vs, is a useful soil mechanical property for determining the low shear strain (γ ≈ 0.0001%) elastic shear modulus, which is required for both static and dynamic response analyses of earth structures. It is an important geotechnical soil property for the design and analysis of geotechnical structures. It can be employed to determine the maximum or small-strain (≤10-3%) dynamic shear modulus (Gmax or G0) of the soil mass. Vs can be easily obtained using laboratory or in situ testing techniques. Laboratory tests can be carried out on undisturbed soil samples by simulating the field stress conditions or reconstituted soil samples from a site. However, obtaining good quality undisturbed samples of granular soil deposits is very difficult and moderately expensive. In most geotechnical investigations, the seismic properties (P- or S-wave velocity and the dynamic elastic properties) of granular soil layers from in situ tests (such as the seismic cone penetration test) cannot be determined because of the high cost of undisturbed specimens and the need for highly specialized personnel and equipment. There is increasing interest in the use of Vs to study soil particle properties (e.g. shape, elastic properties, gradation) and the soil state and fabric (e.g. void ratio, boundary stress). In the current study, the bender element and resonant column tests were conducted on sand-gravel specimens. A bender element is an electro-mechanical transducer composed of two-layers of piezo-ceramic plates that are cross-sectionally polarized. This allows for straightforward wave velocity measurement of soil specimens. The BE converts electrical energy to mechanical energy (movement). The resonant column device is commonly used in the laboratory to measure the low-strain properties of soil. This includes the dynamic properties (shear modulus and damping ratio) of soil specimens at strain levels of 10-6 to 5×10-3 conducted according to ASTM standards. In the RC test, Vs can be calculated using the solution of the equation for the linear vibration of a column-mass system. The RC device is the most reliable laboratory method for measurement of Vs. The aim of this research was to explain the effects on Vs of the relative density, mean effective stress, grading characteristics, consolidation stress ratio and initial fabric anisotropy produced during specimen preparation. Five gradations of gravelly and sandy material were used to study the influence of grading characteristics, consolidation stress ratio, depositional method, relative density and mean effective stress on the dynamic properties of granular soil. The pure sand was clean, uniformly-graded fine sand with a mean grain size of 0.6 and a silt content of less than 1% that was classified as SP according to the unified soil classification system (USCS). The pure gravel was uniformly-graded soil with a maximum particle size of less than 16 mm that was classified as GP according to the USCS. The measured values from the resonant column and bender element tests also were compared. Comparison of Vs-BE and Vs-RC shows that the results obtained by both techniques were in acceptable agreement for all specimens; however, there was a slight difference between the two techniques at low values of Vs in which Vs-BE was consistently lower than the corresponding values of Vs-RC. The results of these tests were employed to develop a generalized relationship for predicting the Vs of granular soil. The Vs model was validated using experimental data from the current study and from previous studies. The results indicate that the proposed model is capable of predicting the Vs of granular soil.سرعت موج برشی در خاکها یکی از پارامترهای مهم در مطالعات دینامیکی خاکها محسوب میشود. این پارامتر در نمونههای المانی خاک از طریق آزمایشهای المانی یا در محل از طریق آزمایشهای ژئوفیزیک قابل ارزیابی است. از جمله روشهای پرکاربرد در آزمایشگاه جهت تخمین سرعت موج برشی در خاکها استفاده از المانهای خمشی و آزمایش ستون تشدید است. در این مقاله با مقایسه نتایج بهدستآمده از المانهای خمشی و ستون تشدید، مقادیر فرکانس مناسب در آزمایش المان خمشی در خاکهای دانهای به دست آمده است. از طرف دیگر تأثیر نسبت منافذ، تنش همهجانبه و درصد شن بر روی سرعت موج برشی مورد بحث قرار گرفته است. نتایج نشان میدهد که با کاهش نسبت منافذ یا افزایش تنش همهجانبه، سرعت موج برشی بهصورت غیرخطی افزایش مییابد. از طرف دیگر با افزایش مقدار شن تا 50 درصد به ماسه میزبان، سرعت موج برشی افزایش یافته و بعد از آن با افزایش شن، سرعت موج برشی کاهش مییابد.https://www.bese.ir/article_240425_a983e742ac3b5f5a66af8ee13a05a07c.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Comparison of the Performance of Metaheuristic Algorithms in Optimal Selection of LQR Weighting Matricesمقایسهی عملکرد الگوریتمهای فراکاوشی در انتخاب بهینهی ماتریسهای وزنی LQR7191240427FAجوادکاتبیدانشگاه تبریز، گروه مهندسی عمران، تبریزموناشعاعی پرچیندانشگاه تبریز، گروه مهندسی عمران، تبریزJournal Article20180415Active control acts as an effective strategy to improve the seismic behavior of structures by calculating and applying the external forces and leads to the adaptive change in dynamic properties of the structure during the earthquake. In the LQR method as the most common control algorithm, the second-order performance index has been optimized to establish a balance between response and control force reduction. In defining the performance index, the relative importance of response reduction and control force reduction is regulated by the selection of Q and R weight matrices. Q and R are the weight matrices for the response and control forces, respectively, and their values indicate the relative importance of response or control force decrement. There is no systematic way to determine these matrices so far these weights are chosen based on trial and error and designer experience. This study has concentrated on metaheuristic algorithms in optimal active control of structures. In this paper, to facilitate the process of controller design, R and Q weighting matrices are considered as design variables and wavelet-based performance index as objective function of metaheuristic optimization. Imperialist competitive algorithm (ICA) as a socio-politically motivated algorithm, differential evolution (DE) as an evolutionary method, bat (BA) and firefly (FA) as natural-inspired algorithms, colliding bodies (CB) as physics-inspired algorithm and harmony search (HS) as music-inspired metaheuristic are used in this study to compare different aspects of metaheuristics in dealing with the optimal active control problem. Some of these metaheuristics have not been explored in control problem yet. In this study, in order to enhance the controller performance, DWT has been applied to decompose the excitation into different frequency bands. For decomposition process, signal is decomposed using Daubechies wavelet of order 10 (db10) mother wavelet in five levels. Defined wavelet-based performance index has been selected as objective function and weighting matrix elements considered as design variables of optimization process. Then, metaheuristic algorithm has been employed to search the optimum weights for each frequency band to calculate the control force in each domain. In addition to wavelet-based LQR performance index used as objective function of optimization, nine benchmark indices obtained from the results are calculated to evaluate the controller-performance by reduction of different design parameters such as interstory drift, story displacement, acceleration, base shear and needed control force compared to the uncontrolled cases. The best solution, convergence rate and computational effort of aforementioned optimization methods for a three-story structure under different artificial earthquakes have been compared. According to the results of simulations, the effectiveness of each algorithm in vibration reduction through various seismic excitations has been evaluated by numerical simulations. This formula is able to be easily performed with any metaheuristic algorithm providing the great flexibility in the active controller design. The results for active control of structures have shown the potential of wavelet and metaheuristic algorithms in vibration control for building structures depending on the user to select the appropriate algorithm or on the problem types and its requirements such as the quality of solution, convergence rate, computational effort, and consuming time. The results indicate the effective role of metaheuristic methods in reducing responses and control forces simultaneously over the LQR method. Considering total cost value, CB, ICA and DE have produced better results compared to all the mentioned algorithms. FA and BA have good convergence tendency compared to other algorithms. Each metaheuristic algorithm has advantages and disadvantages in solving active control problem, whiles the superiority of CB, ICA and DE over other methods in finding the optimal responses for active control problem has been shown as well.کنترل فعال بهعنوان استراتژی مؤثر بهبود رفتار لرزهای سازهها از طریق محاسبه و اعمال نیروی خارجی سبب تغییر تطبیقی مشخصات دینامیکی سازه هنگام وقوع زلزله میگردد. در روش LQR بهعنوان رایجترین الگوریتم کنترل، شاخص عملکرد مرتبهی دومی بهینه میگردد تا توازنی بین کاهش پاسخ و نیروی کنترل برقرار شود. در تعریف شاخص عملکرد اهمیت نسبی کاهش پاسخ و نیروی کنترل با انتخاب ماتریسهای وزنی تنظیم میگردد. تاکنون روشی سیستماتیک برای تعیین این ماتریسها ارائه نشده و انتخاب وزنها بر اساس سعی و خطا و تجربیات طراح صورت میگیرد. در این پژوهش جهت تسهیل روند طراحی کنترلر، عناصر ماتریسهای وزنی R و Q بهعنوان متغیرهای طراحی روشهای فراکاوشی در نظرگرفته شده و شاخص عملکرد مبتنی بر موجک بهینه میگردد. با توجه به تعدد روشهای فراکاوشی، در این مطالعه از شش الگوریتم رقابت استعماری، تکامل تفاضلی، خفاش، کرم شبتاب، اجسام در حال برخورد و جستجوی هارمونی در طراحی کنترلر استفاده شده و عملکرد این روشها مقایسه میشود. نتایج اعمال کنترلر بر سازهی سه درجه آزادی تحت زلزلههای مصنوعی بیانگر نقش مؤثر روشهای فراکاوشی در کاهش پاسخها و نیروهای کنترلی نسبت به روش LQR است. در این مطالعه کنترلرهای اجسام در حال برخورد، رقابت استعماری و تکامل تفاضلی عملکرد بهینهتری از خود نشان دادهاند.https://www.bese.ir/article_240427_32ba49184f9e231628214a5c5ea54ba1.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Sensitivity Analysis of Friction Tuned Mass Damper and its Performance Compared to Tuned Mass Damper at Different Seismic Hazard Levelsتحلیل حساسیت میراگر FTMD و بررسی عملکرد آن در مقایسه با TMD در سطوح مختلف خطر لرزه ای93105240418FAحسینتاجمیر ریاحیگروه مهندسی عمران، دانشکده عمران و حملونقل، دانشگاه اصفهانراحلهشمس فلاورجانیمؤسسه آموزش عالی دانشپژوهانJournal Article20180521One of the most up-to-date seismic control devices are friction tuned mass damper (FTMD). This type of damper is a combination of a tuned mass damper (TMD) and a nonlinear frictional damper. In this paper, the governing equations for a single-degree-of-freedom (SDOF) structure equipped with a FTMD and effective parameters on these systems performance are expressed first. Then, SDOF structures with linear behavior equipped with a FTMD are modeled and validated in OpenSEES software. Finally, the sensitivity analysis of these models to their effective parameters is performed. The structures mass is assumed to be 10 tons, their period is 0.5 second and their damping ratio is assumed to be 2%. Nonlinear time history analyses are done for these structures using 40 strong ground motions from the SAC project. These ground motions consist of 20 records (La01-La20) at design basis earthquake (DBE) level and 20 records (La21-La40) at maximum considered earthquake (MCE) level for the Los Angeles area. Effective parameters on the performance of FTMD assumed in this study are the friction coefficient of the damper, the mass ratio of the damper to the structure and the frequency ratio of the damper to the structure. Average of the structures' maximum displacement is determined for two ground motion records sets and effects of the mentioned parameters on the structural performance are discussed. Results show that the responses are more sensitive to frequency ratio rather than friction coefficient and mass ratio. The best value for the friction coefficient varies between 0.1 and 0.3 at DBE level, and varies between 0.2 and 0.4 for MCE level.<br />Based on the results obtained for SDOF structures, application of FTMD on multi-degree-of-freedom (MDOF) is discussed in the next step. This is done for short period structures because this type of damper is more effective on these structures. Three MDOF structures with linear behavior and period of 0.3, 0.5 and 1 second are selected and the seismic performance of these structures equipped with FTMD is investigated and compared with the same structures equipped with tuned mass damper (TMD). The mass of stories is uniformly distributed among structure and the mass of each story is 10 ton. In addition, the damping ratio for the main structure in all models is assumed to be 2% and the stiffness of the stories is decreased linearly with the triangular pattern. Same ground motion records are used for the nonlinear time history analysis of MDOF structures and the results for the mean maximum relative displacement of the stories under DBE and MCE levels are compared for structures with FTMD and TMD. Results show that the structures equipped with FTMD have better performance than the structures equipped with TMD, but with increasing structures period, performance of two systems approach each other. In addition, 3 and 5 story structures equipped with FTMD have better performance at DBE level while a 10-story structure equipped with this damper has better performance at DBE level.<br /><br />از جمله بهروزترین وسایل کنترل لرزهای، میراگرهای جرمی تنظیمشده اصطکاکی (FTMD) هستند. این نوع میراگر، ترکیبی از میراگر جرمی تنظیمشده (TMD) با سختی خطی و یک میراگر اصطکاکی خالص با رفتار غیرخطی است. در این مقاله، ابتدا به تحلیل حساسیت پاسخهای سازه مجهز به این میراگر در اثر تغییر در نسبت فرکانس، ضریب اصطکاک و نسبت جرمی میراگر پرداخته شده است؛ سپس به کمک این نتایج، پاسخهای لرزهای برای سه سازهی برشی 3، 5 و 10 طبقه در سه حالت سازه بدون میراگر، با FTMD و با TMD مورد بررسی قرار گرفته و در دو سطح خطر لرزهای مقایسه شده است. تحلیلهای انجام شده در نرمافزار OpenSEES و تحت 40 شتابنگاشت پروژه SAC، در دو سطح خطر لرزهای 1 و 2 است. نتایج بهدستآمده حاکی از حساسیت بالاتر پاسخها به نسبت فرکانس، در مقایسه با ضریب اصطکاک و نسبت جرمی است. بهترین مقدار برای ضریب اصطکاک در سطح خطر یک عددی بین 1/0 تا 3/0 و در سطح خطر دو، 2/0 تا 4/0 است. همچنین رفتار سازه با بهکار بردن FTMD در هر سه سازهی 3، 5 و 10 طبقه بهتر از TMD است؛ لیکن با افزایش زمان تناوب سازه تأثیر FTMD به TMD نزدیک میشود.https://www.bese.ir/article_240418_528cf8fa3b49a15721e863be3489592f.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Experimental Investigation of Conventional Methods of Anchoring Masonry Infills to Steel Frames in Iranمطالعه آزمایشگاهی روشهای متداول مهار دیوارهای میانقاب بنایی به قابهای فولادی در ایران107121240419FAمهدیکهریزیگروه عمران، واحد کرمانشاه، دانشگاه آزاد اسلامی، کرمانشاه، ایرانمهرزادتحملی رودسریگروه عمران، واحد کرمانشاه، دانشگاه آزاد اسلامی، کرمانشاه، ایرانJournal Article20171025Depending upon whether or not they are connected to the frame, infill walls display different performances and have varying effects on the structure and the force distribution between building frames. In most of buildings with steel or reinforced concrete frames, to partition the internal space and also to separate the inside of the building from outside, walls with masonry materials are used as infills. Masonry infill walls are composed of small, distinct elements which collectively act as a single unit. Videlicet, the masonry infill wall consists of discrete materials and since discrete materials generally exhibit a brittle behavior, they crack or fail during earthquakes which in most cases results in the loss of lives and capital. Thereupon, predicting solutions for bracing infill walls and preventing them from being destroyed in such a way that the structure can maintain its desirable performance seems necessary. The specifications of infills and the way they are connected to frames can exert considerable influences on the seismic behavior of the structure. In this study, to investigate the conventional methods of anchoring masonry infills to steel frames in Iran, the experimental results of four single-story, single-bay steel frames with the scale of 1:3 are presented, with a special focus on the different details of the connection between the infill wall and the surrounding frame. Three frames with masonry infills and one frame without an infill were constructed using conventional materials in Iran. All of the samples were tested by applying a lateral load on the upper beam. Different details regarding the connection of the infill to the frame including how the infill is connected to an un-anchored frame, connecting the infill to the frame using vertical separating angles, and the use of embedded rebars in the infill. The results showed that using the mentioned details to anchor the infill to the frame is not only quick and convenient, it also suitably delays the cracking of the infill panel, changes the failure modes of the wall, decreases the level of damage and maintains stability in the wall. The employment of these details also exerts a significant influence on the cracking patterns, failure modes, stiffness, strength, ductility, out-of-plane deformations, and energy dissipation.مشخصات میانقابها و نوع اتصال آنها به قاب، میتواند اثرات قابلتوجهی بر رفتار لرزهای سازه داشته باشد. در این مقاله بهمنظور بررسی روشهای متداول مهار دیوارهای میانقاب بنایی در ایران، نتایج آزمایش چهار نمونه قاب فولادی یک طبقه و یک دهانه با مقیاس ، با تمرکز بر جزئیات مختلف اتصال دیوار به قاب ارائه میگردد. سه نمونه دارای دیوار میانقاب بنایی ساخته شده با استفاده از مصالح متداول در ایران هستند و یک قاب بدون میانقاب است. تمام نمونهها با اعمال بار جانبی تنها در تراز تیر فوقانی مورد آزمایش قرار گرفتند. جزئیات مختلفی از تماس و اتصال میانقاب و قاب شامل تماس دیوار و قاب بدون مهار، اتصال و مهار میانقاب با استفاده از نبشیهای جداکننده قائم و میلگردهای مدفون در دیوار بررسی و رفتار آنها در هریک از این موارد بررسی گردید. نتایج نشان میدهد جزئیات ذکر شده جهت اتصال و مهار دیوار میانقاب به قاب، ضمن امکان اجرای سریع و آسان، به نحو مطلوبی سبب تأخیر در ترکخوردگی پانل میانقاب، تغییر حالات شکست دیوار، کاهش میزان آسیبدیدگی و حفظ ایستایی دیوار در جابهجایی جانبی قاب میگردد. همچنین تأثیر قابلتوجهی بر الگوی تشکیل ترکها، مدهای شکست، سختی، مقاومت، شکلپذیری، تغییر شکل خارج از صفحه و میزان اتلاف انرژی دارد.https://www.bese.ir/article_240419_e3b82805c6fa21c1d13b1d38d79e8b78.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Comprehensive Assessment of Damage Indices of RC Frames in Conventional and Novel Seismic Design Approachesارزیابی جامع شاخصهای خسارت قابهای خمشی بتنآرمه در روشهای طراحی لرزهای متداول و نوین123138240421FAزهرهجباری سلمیگروه مهندسی عمران- زلزله، مؤسسه غیرانتفاعی دانشپژوهان پیشرو، اصفهان، ایراناسماعیلایزدی زمان آبادیدانشکده مهندسی عمران، واحد نجف آباد، دانشگاه آزاد اسلامی، نجف آباد، ایرانJournal Article20180519Experience of the past earthquakes reveals that conventional force based design (FBD) approach, only provide minimum requirement for life safety performance level of structures. While these methods do not capable to control structural seismic damages. In recent years, displacement based design approaches have been proposed as the main tools of performance based design. Direct displacement based design (DDBD) is recognized as one of the most efficient methods. In this method, an inelastic multi degree of freedom structure is substituted with an equivalent elastic single degree of freedom. The substitute structure is designed for a target displacement and an equivalent viscous damping using elastic displacement response spectrum. The effectiveness of this method has been examined in controlling the overall seismic demands of many structural systems, while the least attention has been paid to the effects of local damages.<br />In this study, seismic performance of a set of RC frames designed with DDBD and FBD approach (based on Iranian seismic code) has been investigated and compared with a focus on local damages. DDBD and FBD method was applied to four reinforced concrete regular frames of 3, 5, 7 and 11 story and performance of the methods was compared using inelastic time history analysis (ITHA). In the seismic assessment process, in addition to general structural responses, the distribution of local damages has also been investigated. The Park–Ang damage index was selected as the seismic damage index and probability of exceedance of the damage limit state was compared using fragility curves developed for five damage levels.<br />Results show that very good control of displacement and inter-story drift of RC frames designed with DDBD approach. Evaluation of the plastic hinge rotation shows, DDBD unlike FBD approach has been satisfied expected performance level. Furthermore DDBD approach provided more control on selected seismic damage index and distribution of damage index at height of structures is more uniform than FBD approach. The cost analysis shows that consumable rebar is increased 6.6%-52.11% and consumable concrete is up to 3.4% in DDBD approach compared with FBD approach, which is more exponential in frames with higher elevations.عدم رضایت در کنترل ایمنی و پایایی سازههای طراحی شده به روشهای متداول، دلیل گرایش محققین به روشهای طراحی بر اساس عملکرد است. طراحی مستقیم مبتنی بر تغییر مکان یکی از محبوبترین این روشهاست. تحقیقات گذشته در بررسی شاخصهای کلی سازهها تا حد زیادی کارایی این روش را تأیید میکنند. لیکن بررسی جامعتر آن مستلزم برآورد خسارت المانها و وارد شدن به حیطه ارزیابیهای احتمالاتی میباشد. هدف از این مطالعه بررسی روش طراحی مستقیم از چهار دیدگاه مختلف شامل تغییر مکان جانبی نسبی، خسارتهای موضعی، ارزیابی احتمالاتی و هزینه ساخت میباشد. بهمنظور بررسی پاسخ تغییر مکانی و خسارتهای موضعی سازهها از چهار قاب خمشی بتنآرمه با ارتفاع 3، 5، 7 و 11 طبقه استفاده شده است. نتایج نشاندهندهی تأمین سطح عملکرد انتخابی در خصوص پاسخهای تغییر مکانی و عدم تجاوز دوران مفاصل پلاستیک از سطح ایمنی جانی در روش طراحی مستقیم برخلاف روش نیرویی میباشند. نتایج ارزیابی احتمالاتی در پنج حالت خرابی در دو دسته از قابها نشاندهندهی احتمال خرابی کمتر در روش طراحی مستقیم برخلاف روش نیرویی میباشد. ضمن اینکه تحلیل هزینه نشاندهندهی افزایش آرماتور مصرفی بین 6/6 تا 11/52 درصد و افزایش بتن مصرفی تا 4/3 درصد در روش طراحی مستقیم نسبت به روش نیرویی میباشد.https://www.bese.ir/article_240421_f05965f26f8d0f6dcc2b7998f7da8fd3.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Vulnerability Assessment of Retrofitted Weak Reinforced Concrete Frames with Different Methods and Levels Using Fragility Curves and Cost-Benefit Analysisارزیابی آسیبپذیری قابهای ضعیف بتن مسلح مقاوم شده با روشها و ترازهای مختلف به کمک منحنی شکنندگی و تحلیل هزینه فایده139157240422FAپیاماسدیدانشکده عمران، دانشگاه صنعتی اصفهانحسینبهارلودانشکده عمران، دانشگاه صنعتی اصفهانJournal Article20180224Purpose<br />Different structural solutions are employed to enhance the capacity of weak structures under the earthquake excitations to satisfy the target of the rehabilitation regulations. These retrofitting methods include adding new seismic-resistant components or increasing the strength and ductility of existing components. Given the probability of the earthquake occurrence, it is necessary to evaluate the effect of different retrofitting scenarios on the probabilistic performance of the structure. In this paper, a framework using fragility curves is presented to select the most efficient retrofit scenario in terms of the cost-benefit analysis. For this purpose, two methods of adding reinforced concrete (RC) shear walls and use of polymeric reinforced carbon fiber (CFRP) sheets are employed to retrofit weak RC frames of 5, 8 and 12-stories. Different retrofitting scenarios for RC frames were compared using the proposed framework.<br />Methodology<br />Following the presented framework, the damage indices of structures of each scenario are extracted from the incremental nonlinear dynamic analysis. Then, the fragility curve, the damage probability matrix, and the expected annual damage costs are obtained. In the last step, different scenarios were compared using cost-benefit analysis. The benefits and costs included in the cost-benefit analysis were the reductions of the annual damage cost and cost of each structural retrofitting scenario, respectively. The higher the benefit-cost ratio, the more economical the scenario is. IDARC [1] software was employed for dynamic nonlinear structural analysis. For modeling the hysteresis deteriorations in dynamic analyses, stiffness, resistance, and pinching deterioration parameters were employed. These parameters are obtained based on the relationships proposed in [2] to accommodate the hysteresis of the numerical modeling with the experimental one. The weak RC frames were retrofitted with the basis rehabilitation target by the Iranian rehabilitation Guidelines [3], signifying that the performance level of the structure is life safety (LS) under the design seismic risk (0.25 g). Also, for better evaluation of the retrofitting methods, retrofitting was conducted at two higher levels.<br />Conclusions<br />The results of the nonlinear dynamical analysis showed that shear walls can reduce the inter-story drift ratios significantly more than CFRP sheets do. The results of the cost-benefit analysis revealed that retrofitting with the CFRP sheets is a more preferable method than retrofitting with the shear walls in terms of the economic approach, especially for the shorter height structure (5-story frames). It is because the cost of executing shear walls and shear wall foundations is very expensive. By increasing the structural height (from 5 to 8 and 15 stories), CFRP sheets outperformed shear walls, while for the 15-story frame, adding the CFRP sheets was a better solution than adding the shear walls. For high- and middle-height structures (8- and 15-story frames), the differences in the cost-benefit ratio of the two methods were ignorable. The CFRP sheets further reduced the exceedance probability of damages at low earthquake hazard levels, while shear walls further reduced the probability of damage occurrence and damage exceedance (especially high-performance levels such as collapse prevention). This is especially the case for higher-rise structures where the collapse probabilities are higher than for the shorter structures, leading to a close cost-benefit ratio of the two retrofitting methods.
References<br />1. Valles, R.E., et al. (2009) IDARC2D Version 7.0: a Computer Program for the Inelastic Damage Analysis of Buildings. NCEER, State Univ. of New York at Buffalo, technical report MCEER-09-0006.<br />2. Bakhshi, A. and Asadi, P. (2013) Probabilistic evaluation of seismic design parameters of RC frames based on fragility curves. Scientia Iranica, 20(2), 231-241.<br />3. Strategic Oversight Deputy, Technical System Affairs (2013) Guideline for Seismic Rehabilitation of Existing Buildings, Publication No. 360, (1st revision) (in Persian).با کمک راهکارهای مختلف سازهای مانند افزودن عناصر جدید لرزهبر و یا افزایش مقاومت و شکلپذیری عناصر موجود، ظرفیت سازههای ضعیف در برابر تحریک زلزله تا حد پذیرش آییننامه بهسازی افزایش مییابد. اما با توجه به احتمالاتی بودن اثر تحریک زلزله، لازم است اثر این مقاومسازی بر روی عملکرد احتمالاتی سازه سنجیده شود. در این مقاله، با توجه به تنوع راهکارهای مقاومسازی و امکان انجام آن در ترازهای مختلف، چارچوبی با استفاده از منحنیهای شکنندگی استفاده شده است، تا ضمن لحاظ اثرات احتمالاتی رخداد زلزله، به کمک تحلیل هزینهفایده بهترین و مناسبترین راهکار مقاومسازی انتخاب گردد. بدینمنظور، دو روش اضافه کردن دیوار برشی بتنآرمه و استفاده از ورقهای الیاف کربنی مسلح پلیمری (CFRP) برای مقاومسازی سازههای ضعیف بتنی استفاده شده است. آسیبپذیری سازههای مقاوم شده در ترازهای مختلف مقاومسازی، نسبت به سازه ضعیف اولیه ارزیابی شده است. نتایج تحلیلها برای سازههای 5، 8 و 15 طبقه مورد بررسی، نشان داده است که استفاده از ورقهای CFRP همواره اقتصادیتر است، ولی چون دیوارهای برشی در شدتهای بالای زلزله، احتمال فراگذشت از حدود عملکردی آستانه فروریزش را بیشتر کاهش میدهند، در سازههای بلند که آسیبپذیرتر هستند، نسبت فایده به هزینه، دو روش به یکدیگر نزدیک شدهاند.https://www.bese.ir/article_240422_43e63298ff802b6b0f75286880727353.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Damage Detection in Beam Structures Using Statistical Analysis of Hilbert-Huang Transformation of Measured Responseتشخیص خرابی سازه تیر با استفاده از تحلیل آماری پاسخهای اندازهگیری شده و تبدیل هیلبرت-هوانگ159174240423FAمحمدجوادخسرویانیگروه مهندسی عمران، واحد قزوین، دانشگاه آزاد اسلامی، قزوین، ایرانمجیدقاسمیگروه مهندسی عمران، واحد قزوین، دانشگاه آزاد اسلامی، قزوین، ایرانJournal Article20180908One of the main concerns for structures and infrastructures is to evaluate their reliability and functionality as they can suffer long-term damage due to gradual deterioration over time, or they can be imposed to natural or manmade hazards and overloading during their lifetime. Thus, Structural Health Monitoring (SHM) has been a hot research topic in order to introduce efficient methods and feasible techniques for evaluating, monitoring and improving structural reliability and life cycle management. The SHM process typically includes three stages: a) data acquisition: measurement of the structural responses using an array of sensors; b) extraction of damage-sensitive features; and c) analysis of extracted features to develop statistical models and estimate structure health condition.<br />During the last decades, vibration-based damage detection methods have been greatly developed. The purpose of these methods is to determine the resulting changes in structural properties including stiffness, natural frequency, mode shape and damping ratio of the structure. For example, the basis of the Fourier Transform (FT) method is to determine the structural modal parameters from the random vibration data in the frequency range. Since local damages mostly impact higher frequency modes which are hard to excite and detect, most of FT based methods are unable to detect local or light damages accurately. Therefore, time-frequency analysis is introduced to overcome the limitations of the Fourier method, the most important of which is not providing a frequency-time range of a signal. The first case of frequency-time analysis was the short-time Fourier transform method based on the Fourier transform of the data divided by the time window function. According to this method, the interaction between time and frequency is difficult due to the existence of the time window function. If the windows are smaller in the time segment, its accuracy increases and in the frequency domain it becomes less accurate.<br />The signal processing techniques such as wavelet transform and the Hilbert-Huang transform are playing an increasingly important role in structural health monitoring. Hilbert-Huang transform (HHT) is a novel signal-processing technique for analysing nonstationary and nonlinear signals. HHT method consists of empirical mode decomposition (EMD) and Hilbert transform (HT). According to this theory, the primary signals can be decomposed into different basic time-dependent intrinsic mode functions (IMFs) through the empirical mode decomposition (EMD). Afterward, instantaneous frequency and amplitude of each IMF can be obtained as Hilbert–Huang spectrum. The application of HHT based approaches in structural health monitoring has been widely studied through the numerical and experimental researches.<br />This paper proposes a damage detection method based on the amplitude coefficient correlation of responses of damaged and undamaged structures using Hilbert–Huang transform (HHT). Structural responses have been decomposed to intrinsic mode functions (IMFs) through the empirical mode decomposition (EMD) method and the changes appear in the first IMF. Therefore, every change on the original signal can be revealed on IMFs, since the original signal depends on IMFs. Also, these changes have an effect on the analytical signal and the Hilbert transform. The instantaneous amplitude in measured joints on the structure is calculated using the Hilbert transform of the first IMF of response. The coefficient correlation matrix of the damaged and undamaged elements is demonstrated by graphical diagram in order to estimate the location of the damage. In this research, the accuracy of proposed damage detection method has been verified by applying the method on a finite element model of two-span continuous concrete beam structure.
The concrete beam is 80 m long with two equal 40 m span bays covered by a concrete deck with 0.5 m thickness. The dynamic responses of the beam at all sensors have been obtained by numerical analysis of finite element model under triangular pulse loading. The responses were also contaminated with 2% random noise to consider measurement uncertainties. The damage has been modelled as stiffness reduction in a 1.25 m long segment of finite element model of beam. To evaluate the efficiency of the proposed method, different damage scenarios are studied.<br />IMFs of all responses at sensor locations were obtained by combination of EMD and HT, and the instantaneous frequency and amplitude of Hilbert were derived. Auto correlation of instantaneous amplitude of undamaged and damaged structures were calculated and introduced as Damage Index Correlation. According to the results, this method is able to trace the location of the damage by the comparison of the correlation coefficients. Therefore, the locations of damages in different scenarios were located with a variety of coefficients correlation in sensors. The results show that the proposed method can determine the location of the damage with an acceptable accuracy for low and moderate damage intensities in all damage scenarios.در این مقاله یک روش جدید تشخیص خرابی بر اساس تبدیل هیلبرت- هوانگ پاسخهای اندازهگیری شده سازه تیر ارائه شده است. توابع مودی ذاتی پاسخهای دینامیکی سازه با استفاده از تجزیه مودی تجربی در نقاط مشخص محاسبه شده و تبدیل هیلبرت برای محاسبه دامنه آنی بر روی هر تابع مودی ذاتی به کار برده شده است. ضریب همبستگی و تابع همبستگی متقابل دامنه آنی پاسخهای سالم و خراب سازه محاسبه شدهاند. محل خرابی از طریق تعریف پارامتر شاخص خرابی و مقایسه نمودار آنها در حالتهای سالم و خراب به دست آمدهاند. برای ارزیابی و دقت روش یک مدل المان محدود سازه تیر بتنی دو دهانه مدل شده است. پاسخهای دینامیکی تیر با استفاده از تحلیل عددی تحت بارگذاری مثلثی مشخص به دست آمدهاند. با توجه به نوفههای اندازهگیری، به پاسخهای دینامیکی مقادیر نوفه اضافه شده و نتایج مورد بررسی قرار گرفته است. نتایج حاصل نشان دادند که روش ارائه شده محل خرابی را با دقت خوبی تشخیص میدهد.https://www.bese.ir/article_240423_252e58e3c9c506a9bf3444ef00aab2fb.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Accurately Estimaion of Story Drifts of Stell Medium moment Frame Buldings, Considering Panel Zone Effectsدر نظرگیری اثر چشمه اتصال در برآورد دقیق تغییر مکان لرزه ای طبقه در قاب های فولادی خمشی متوسط175187240426FAزیبادارابیدانشگاه علم و فرهنگمجیدمحمدیپژوهشگاه بینالمللی زلزله شناسی و مهندسی زلزلهJournal Article20171226In seismic design codes, the maximum real relative displacement due to nonlinear behavior of the structure is estimated from variation coefficient of the relative linear displacement multiplied by the coefficient of deflection amplification factor (Cd). This coefficient is obtained by considering nonlinear displacement of the members of the structure and depends on the lateral load-resisting system. The previous studies indicate that the panel zone can have a significant effect on the behavior of a frame, and in particular, its lateral displacement. Therefore, to predict the precise behavior of the frame, the effect of the panel zone should be considered, but this factor has not been included in the estimation of the Cd value so far. Therefore, the storey drifts are under-estimated. The main purpose of this study is to consider the effect of the panel zone on Cd for Intermediate Moment Resisting Steel Frames (IMRSF). In this regard, two buildings have been designed based on the Iranian seismic design codes in ETABS software. A 4-story building is designed twice, once by I-section columns, and the other by box section columns. The structure with IPE sections has an IMRSF and, a Concentric Bracing Frame (CBF) with conventional ductility in two main directions. However, the structure of the box section has an IMRSF in both directions. After designing the structures, a flexural frame was selected from both structures and was modeled in the OpenSees Software for two conditions: with and without modeling panel zones. Incremental Dynamic Analyses (IDA) has been performed for 46 ground motion records.<br />To determine a correction factor for Cd in order to consider the panel zone effects, the ratio of the nonlinear maximum drift that of the model without panel zone effects is calculated for each ground motion. The results of the analyses show that in general, considering the effect of the panel zone in the analytical model, leads to an increase in the maximum drift values and ignoring the effect of the panel zone in the structure with the I or Box sections, causes the displacement of the floors to be 28% and 16% less than actually estimated, respectively. This effect for the structure with IPE sections is greater than Box sections, for its smaller web thickness and thus lower thickness of the panel zone. Therefore, it can be concluded that the thickness of the panel zone plays a key role in the structural response. Finally, it is recommended to increase Cd coefficient of intermediate moment resisting frames as 1.28 and 1.16 for the structures with I-section and Box-sections in their columns, respectively.در آییننامههای طراحی لرزهای، بیشینه تغییرمکان نسبی واقعی ناشی از رفتار غیر الاستیک سازه، از حاصلضرب تغییرمکان نسبی حاصل از تحلیل الاستیک خطی در ضریب افزایش تغییر مکان(Cd) برآورد میشود. این ضریب با در نظرگیری تغییر مکانهای غیرخطی اعضای سازه بهدست آمده و مقدار آن تابع نوع سیستم سازهای میباشد. اثر چشمه اتصال، یکی از عوامل مؤثر در افزایش تغییر مکان جانبی طبقات میباشد ولی این عامل در برآورد مقدار ضریب Cd لحاظ نشده است. هدف اصلی این مطالعه، درنظرگیری اثر چشمه اتصال در این ضریب برای ساختمانهای دارای قاب خمشی فولادی متوسط میباشد. به این منظور، یک ساختمان چهار طبقه، یکبار با مقطع I شکل و یکبار با مقطع قوطی طراحی شده است. قابهای خمشی مورد نظر تحت تأثیر 46 رکورد با خصوصیات لرزهای متفاوت قرار گرفته و از روش دینامیکی غیرخطی برای تحلیل استفاده شده است. نتیجه این مطالعه نشان میدهد که صرفنظر کردن از اثر چشمه اتصال در سازه با مقطع I شکل و قوطی، باعث میشود جابهجایی طبقات بهترتیب 28 و 16 درصد کمتر از واقع تخمین زده شود. بنابراین بر اساس فرضیات و نتایج حاصل از این تحقیق، باید ضریب Cd موجود در آییننامهها را برای قابهای خمشی متوسط فولادی دارای اینگونه مقاطع به همین میزان افزایش داد.https://www.bese.ir/article_240426_869cdcfa49fdf185c550d2fe87fd4bee.pdfپژوهشگاه بین المللی زلزله شناسی و مهندسی زلزلهفصلنامه علوم و مهندسی زلزله2476-60977120200320Investigation on the Effect of Near and Far Field on the Strongback Bracing Systemمطالعهی اثر زلزلههای حوزهی دور و نزدیک بر روی سیستم سازهای مهاربند ستونفقراتی189204240417FAعلیرضاتورانی، دانشکده مهندسی عمران، دانشگاه سمنان، سمنانمجیدقلهکیدانشکده مهندسی عمران، دانشگاه سمنان، سمنانرضاوهدانیدانشکده مهندسی عمران، دانشگاه سمنان، سمنانJournal Article20180203This paper examines a newly developed seismic force-resisting system. To achieve improved seismic performance, the strongback system combines aspects of a traditional concentric braced frame with a mast to form a hybrid system. The mast acts like a strongback to help resist the tendency of concentric braced frames to concentrate damage in one or a few stories during severe seismic excitations. The purpose of the strongback system is to promote uniform story drifts over the height of a structure. For this purpose, in this paper, the design principles for achieving the desired goal, along with a new relationship for controlling the amount of story drift uniform index for this system is presented and the nonlinear dynamic behavior of structures 3, 6 and 12 stories with three seismic force-resisting system with different configuration at the intersection of the braces to the beam under seven acceleration of far and seven acceleration of near field for achieving the correctness of the design principles and comparing the effects of the near and far field earthquakes has been studied. The strongback bracing system is specifically designed to prevent the uniform story drift and alleviate the soft-story mechanism [2]. The design procedure is such to keep strong-back aspects elastic and stress ratio less than 0.5. Although the seismic codes specify limits for story stiffness and resistance ratio, this limitation does not guarantee to avoid damage concentration. It should be noted that the concept of uniformity is a relative concept and all stories can never have equal and uniform drift in a structure under earthquake. However, a structure can be designed such that the drifts are distributed uniformly in all stories approximately. For uniform story drift and prevention of soft-story in this system, it is not just enough to keep the stress ratio less than 0.5 so as to completely design this system, and the necessary examinations were carried out to reach a relation between conventional braces and aspects of strongback. In addition, studies by Lai and Mahin [2] show that the simple design strategy used does not result in adequate member sizes near the top of the strongback systems and limited yielding of the strongback spine occurs at these levels. According to the ratio of the braces length and Dimensions of their sections, when the stress ratio in strongback should be less than 0.5, this result was obtained some limitation must be considered about conventional braces stiffness ratio and the aspects of strongback. Therefore, by considering the issue of elastic state of the components of strongback in earthquakes, conventional braces were designed for code earthquakes force and stiffness ratio of strongback braces to conventional braces is in each story equal to or more than 2.5 and section of strongback zipper member was considered equal to section of strongback brace member in the story. During these tests, which were performed using the trial and error method, various earthquakes were used to perform the nonlinear time history analysis and various values were considered for the stiffness ratio of strongback braces to conventional braces and were evaluated, which revealed that the stiffness ratio of 2.5 would cause a more uniform distribution of drift along the height of the structure and was the basis for the design of the braces of this system. Results show that the proposed design principles, which are proportional to the stiffness ratio of bracing, are presented by providing an index of uniformity distribution error in structures 3, 6 and 12 stories, which occurred less than 6, 4.8 and 8.6 respectively. Also by creating a difference of 0.5% between the maximum and minimum of the story drift ratio in most of the structures studied, it has been able to hold the strongback truss in elastic to nonlinear analysis, reduce the concentration of deformations and prevent the creation of a soft story structure.این مقاله یک سیستم جدید توسعهیافتهی نیرو- مقاومت لرزهای را بررسی میکند. سیستم ستونفقراتی برای رسیدن به بهبود عملکرد لرزهای، اعضای قاب مهاربندیشده هممرکز متعارف را با یک خرپای قوی به شکل سیستم مختلط ترکیب میکند. خرپای قوی مانند یک ستون فقرات در برابر تمایل قابهای مهاربندیشده هممحور به تمرکز آسیب در یک یا چند طبقه در طول تحریک شدید لرزهای مقاومت میکند. هدف از سیستم ستونفقراتی توزیع یکنواخت دریفتهای طبقه در ارتفاع یک ساختمان است. بر این اساس، در این مقاله مبانی طراحی جهت رسیدن به هدف مورد نظر به همراه رابطهی نوینی برای کنترل میزان شاخص یکنواختی دریفت طبقات برای این سیستم ارائه شده و رفتار دینامیکی غیرخطی سازههای 3، 6 و 12 طبقه با سه نمونه سیستم نیرو- مقاوم لرزهای دارای پیکربندی مختلف در محل تقاطع مهاربندها به تیر تحت هفت شتابنگاشت دور و هفت شتابنگاشت نزدیک گسل جهت رسیدن به صحت مبانی طراحی و همچنین مقایسهی اثرات زلزلههای دور و نزدیک گسل مورد بررسی قرار گرفته است. نتایج نشان میدهد که مبانی طراحی پیشنهاد شده که متناسب با نسبت سختی مهاربندها میباشد، با ارائهی شاخص درصد خطای توزیع یکنواختی مناسبی در سازههای 3، 6 و 12 طبقه که بهترتیب کمتر از 6، 8/4 و 6/8 درصد رخ داده و همچنین با ایجاد اختلاف 5/0 درصد بین بیشترین و کمترین دریفت طبقات در اکثر سازههای مورد مطالعه، توانسته خرپای ستونفقراتی را در تحلیل غیرخطی بهصورت الاستیک نگه دارد، تمرکز تغییر شکل را کاهش و از ایجاد طبقهی نرم در سازه جلوگیری کند.https://www.bese.ir/article_240417_d0a5730daa8247433dbac92ae91f6ff2.pdf