27 research outputs found

    Probabilistic seismic vulnerability assessment of the structural deficiencies in Iranian in-filled RC frame structures

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    A majority of Iranian residential buildings have RC frame structures which are in-filled with masonry walls. Structural deficiencies of in-filled RC frame structures are focused in this probabilistic seismic assessment. The seismic design of 3, 5 and 8 story RC frame structures are carried out according to the current Iranian seismic code and then 3 dimensional analytical models analyzed based on Incremental Dynamic Analysis (IDA) in OpenSEES. The demand statistics in terms of maximum inter-story drift ratio are obtained for 20 sets of ground motion records and the capacity is determined according to the HAZUS-MH limit states and finally the corresponding fragility curves are developed. The results represent the effect of the story numbers, structural deficiency and masonry infill walls in the seismic vulnerability of this subclass of structures

    Evaluation of NSP and MPA Methods to Optimize Special Truss Moment Frames (STMF) Using Island Genetic Algorithm

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    The purpose of the present study is to evaluate the Pushover (NSP) and Modal Pushover (MPA) analysis methods in optimizing Special Truss Moment Frames (STMF) using island genetic algorithm. For this purpose, the optimization program is written and developed in Matlab software, and OpenSees software is used for structural analysis. The design variables of truss arrangement, cross section of members, truss height values and length of special zone of truss moment frame are considered. The constraints of the optimization problem are based on the rules and restrictions of AISC341-16. Case studies were performed on five frames of 3, 6, 9, 12 and 15 stories with a story height of 3 meters and span length of 18 meters with the aim of minimizing weight and maximizing the response modification factor. The results of these analyses are compared with nonlinear dynamic time history analyses as the most accurate method available, which could be used to finally identify and introduce the most efficient method in these structures. The MPA method was able to show better performance than the NSP method in estimating the maximum response of the structure. Despite the excellent performance of this method, Evaluation of numerical results of this study indicates the non-economic nature of MPA method for low-rise structures, and the acceptable efficiency of this method for medium-height to high-rise structures

    Probabilistic Seismic Performance Assessment of Tall RC Special Moment-resisting Frame Buildings Equipped with Buckling-restrained Braces under Near-field Excitations

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    Many tall buildings have already been constructed near faults throughout the world, several of which have sustained casualties and economic losses during strong ground motions. This study investigates the effect of near-fault excitations on the vulnerability of tall, reinforced concrete (RC) special moment-resisting frame (SMRF) buildings equipped with buckling-restrained braces (BRBs) using seismic fragility curves. After attaining the structure’s response modification factor (R), three-dimensional (3D) models of 15-, 25- and 35-story frames were developed by the OpenSees software according to the Iranian code provisions. Thus, the seismic response of the elements was obtained. Subsequently, incremental dynamic analysis (IDA) was conducted by selecting a suitable number of compatible accelerograms in two near-field and far-field groups. Considering the maximum story drift as the demand parameter and selecting the interstory drift ratios (IDR) for the slight, moderate, extensive, and complete collapse seismic performance levels proposed by Hazus, IDA curves were plotted. Then, the seismic fragility curves were produced using the structural reliability relations. The median fragility at complete collapse damage level reduced from 0.73g, 0.62g, and 0.61g to 0.68g, 0.59, and 0.57g for the 15-, 25, and 35-story near-field and far-field earthquake models, respectively. This was attributed to increasing vulnerability and seismic fragility of the structures as a result of both height increase and distance reduction from fault. Based on the results, the most vulnerable structure, i.e., the 35-story near-fault model, experienced a 40, 17, 18, and 6% increase in median fragility at slight, moderate, extensive, and complete collapse damage levels, respectively

    Function of Irony in Two Stories of Rumi's Masnavi

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    In Literary Terms, Irony is a way of Speaking which could be Equivalent to Satire, Metaphor, Opposition, Image, Jest and ect. In other Words, Sarcasm or Implying Something unreal that Teases your Audience or makes them Bewildered could be Called Irony. This Concept began in Greece a long Time ago and then came into its Literalized and Reinforced Concept in Europe. Rumi’s Masnavi is an Ironic Works which to Understand it, the Ironical Parts Need to be Recognized and new Concepts Need to be Achieved. In the Article Ahead, after Defining Irony and an Introductory Statement of that, Classifying all Types of Irony and its Elements to Comprehend Irony has been Accomplished and at the end, the Function of Irony in the Stories of Rumi’s Masnavi has Surveyed and Brought in. In this Article the Basis of the Text Considered to Prove Irony in Masnavi was two Stories: “Parrot and Merchant” and “Grocery and Parrot”. Reading this Article came the Reader into the Conclusion that Masnavi Includes Involute and deep Layers which we can Pass them and find out more Precise Concept of Masnavi. At the end of this Article, it is Concluded that Masnavi Contains Nested and deep Layers that can be Traversed Through Irony and more Precise Concepts can be Understood

    The Effect of Near-Fault Earthquake on Seismic Behavior of Concrete Buildings

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    Due to losses and damages incurred by earthquake in seismic countries, necessity of design of earthquake- resistant structures seems inevitable. For design of a building to resist against earthquake, it is necessary to have comprehensive information about the behavior of building against forces resulted from earthquake. It must be noted that following terms and conditions of seismic design regulations do not ensure the resistance of buildings against seismic forces. For this reason, behavior of structures must be taken into account generally and accurately. In this study, effect of near-fault earthquakes on plasticity of the concrete buildings will be studied in accordance with regulation 2800. For this end, three near-fault earthquakes were selected and matched with Seismo Signal software according to regulations and then, the effect of these earthquakes on three 5, 10 and 15-storey concrete buildings is analyzed

    Expanding the application of haplotype-based genomic predictions to the wild: A case of antibody response against Teladorsagia circumcincta in Soay sheep

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    BackgroundGenomic prediction of breeding values (GP) has been adopted in evolutionary genomic studies to uncover microevolutionary processes of wild populations or improve captive breeding strategies. While recent evolutionary studies applied GP with individual single nucleotide polymorphism (SNP), haplotype-based GP could outperform individual SNP predictions through better capturing the linkage disequilibrium (LD) between the SNP and quantitative trait loci (QTL). This study aimed to evaluate the accuracy and bias of haplotype-based GP of immunoglobulin (Ig) A (IgA), IgE, and IgG against Teladorsagia circumcincta in lambs of an unmanaged sheep population (Soay breed) based on Genomic Best Linear Unbiased Prediction (GBLUP) and five Bayesian [BayesA, BayesB, BayesC pi, Bayesian Lasso (BayesL), and BayesR] methods.ResultsThe accuracy and bias of GPs using SNP, haplotypic pseudo-SNP from blocks with different LD thresholds (0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.00), or the combinations of pseudo-SNPs and non-LD clustered SNPs were obtained. Across methods and marker sets, higher ranges of genomic estimated breeding values (GEBV) accuracies were observed for IgA (0.20 to 0.49), followed by IgE (0.08 to 0.20) and IgG (0.05 to 0.14). Considering the methods evaluated, up to 8% gains in GP accuracy of IgG were achieved using pseudo-SNPs compared to SNPs. Up to 3% gain in GP accuracy for IgA was also obtained using the combinations of the pseudo-SNPs with non-clustered SNPs in comparison to fitting individual SNP. No improvement in GP accuracy of IgE was observed using haplotypic pseudo-SNPs or their combination with non-clustered SNPs compared to individual SNP. Bayesian methods outperformed GBLUP for all traits. Most scenarios yielded lower accuracies for all traits with an increased LD threshold. GP models using haplotypic pseudo-SNPs predicted less-biased GEBVs mainly for IgG. For this trait, lower bias was observed with higher LD thresholds, whereas no distinct trend was observed for other traits with changes in LD.ConclusionsHaplotype information improves GP performance of anti-helminthic antibody traits of IgA and IgG compared to fitting individual SNP. The observed gains in the predictive performances indicate that haplotype-based methods could benefit GP of some traits in wild animal populations

    Unilateral Oculomotor Nerve Palsy as a Rare Manifestation of Isolated Pre-Communicating Segment of Posterior Cerebral Artery Thrombosis

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    Ipsilateral mydriasis (IM) is usually not acute. However, the acute occurrence of unilateral dilated pupil may result in acute ischemic stroke. Herein, we present 3 patients with IM, lateral eye deviation, ptosis, and contralateral hemiparesis due to isolated occlusion of the pre-communicating segment of the posterior cerebral artery with preservation of the posterior communicating artery, which was successfully treated by emergent mechanical thrombectomy. In a 3-month follow-up, all patients were independent without any neurological deficits

    Development and analysis of the Soil Water Infiltration Global database

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    In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements ( ∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76% of the experimental sites with agricultural land use as the dominant type ( ∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it

    Probabilistic seismic assessment of RC frame structures in North of Iran using fragility curves

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    In this article, the fragility curves of RC structures with 3, 5 and 8 stories in Iran have been studied. The structures which have been estimated in this article have the system of RC Intermediate Moment Frame which is designed in accordance with Standard No. 2800 (Third Edition). These models in order to make a non-linear analysis in 3D form, they were modeled in OpenSEES software. The structure analysis was selected of the type of increasing dynamic analysis. In selecting the records of the earthquakes, it was tried that the characteristics of the selected records to be close to the conditions of the construction as much as possible. For this reason, the far-from the fault records of the FEMA P695 Code was used. The selected records were scaled from 0.1g to 1.5g with 0.1g steps and in each step, the structure was analyzed. The IDA curves were drawn for three types of structures under consideration up to structural complete damage. Then using MATLAB software and considering the lognormal probability distribution, the failure probability for each performance level was calculated and the fragility curves for Max Inter Story Drift in different levels of PGA were drawn. The results indicate that in comparing the structure behavior with different heights, it can be said that with the increase of height, the structure reaches to non-linear zone sooner and the structure capacity decreases. In general, with the structure height increase, the structure vulnerability in four specified levels of damage (slight, moderate, extensive and complete) increases but the trend of the increase of damage probability decreases. For the low rise RC structures (Intermediate moment-resisting frame) which have been built in accordance with the Standard No. 2800 (Third Edition), the Probability of extensive and complete damage in earthquakes with PGA’s less than 0.4g and 1.0g accordingly is almost insignificant. For the mid and high rise buildings, the probability of extensive and complete damages in earthquakes with PGA’s less than 0.3g and 0.7g is almost insignificant

    Probabilistic Evaluation of Seismic Performance of Steel Buildings with Torsional Irregularities in Plan and Soft Story under Mainshock-Aftershock Sequence

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    Due to the tectonic plate movement, numerous aftershocks may occur following an earthquake. There are several real mainshock-aftershock ground motion records in which the peak ground acceleration of aftershock is greater than that of the mainshock. Furthermore, irregularities such as soft story and torsional irregularity may change the structural behavior under the influence of earthquakes. This study investigates the fragility curves associated with the three-, five-, and eight-story models with steel moment-resisting frames under the main earthquake and mainshock-aftershock sequence to probabilistically evaluate the aftershock impacts on the steel structures with irregularities in the plan and height. The seismic fragility curves were calculated for four damage levels by selecting the relative displacement capacity at seismic performance levels of slight, moderate, extensive, and complete damage from the US HAZUS code. The analysis was done using structural reliability relationships and incremental dynamic analysis with the OpenSees software platform. The analytical results showed that the structures with soft-story and torsional irregularity were more vulnerable with an increasing number of stories. Also, aftershocks were found to have a more destructive effect on low-rise models. The probability of structural collapse in a given peak ground acceleration for a damaged state due to the mainshock-aftershock sequence is higher than that of the mainshock sequence
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