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This paper describes the seismic performance of a steel frame with additional LYP steel dampers. LYP steel dampers provides passive energy dissipation device in a structure, it also reduces the lateral forces in efficient way which is produced by seismic wave. The seismic performance of structures is needed in the design of structure, especially in countries where seismic activities occur. This analysis is accomplished with the FEM and software called SAP2000. The steel frame is only analyzed using numerical simulation. This paper describes two steel frames, the first steel frame is a two story steel frame without LYP steel dampers while the second steel frame has with LYP steel dampers. The seismic mechanism analysis was accomplished with the help of nonlinear time history analysis technique and the results for inter-story drift, steel frames, base shear, the displacement of the top story and the stress of the dampers was obtained. The time history analysis was taken out with three different earthquake waves according to the Chinese code for the seismic design of buildings; the earthquake waves were divided into the three different earthquake levels in China which include the frequent, moderate and rare earthquake level. The seismic mechanism analysis was accomplished on the three different earthquakes and three different earthquake levels in China. The modal analysis was taken to obtain the frequency and the period of the steel frames. The steel frames were examined under the different load combination which is also described in the code for the seismic design of buildings to obtain the internal forces of the members of the steel frame which include the axial force, shear force and bending moment. The different load combinations are used to get the stress of the dampers. We notice that the addition of LYP steel dampers increases the seismic resistance of the steel frame as we can observe by a reduction in the displacement of the top story, base shear, and inter-story drift angle by the addition of LYP steel dampers on the steel frame. We can be able to observe the behavior of the frames under the different earthquake levels in China using the pushover analysis.

Using seesaw structural system equipped with energy dissipating devices has been considered as a low-cost and low-tech way for creation of earthquake-resilient buildings. In this paper by considering three groups of multi-story buildings, including conventional buildings, LRB-based isolated buildings and building with seesaw structure, equipped with a newly introduced type of structural fuses, their seismic performances have been compared through nonlinear time history analyses (NLTHA). The employed fuses in seesaw buildings are a specific type of yielding plate dampers, called Multiple Curved Yielding Plate Energy Dissipater (MCYPED), installed at the bottom of the all circumferential columns of the lowest story of the building. To show the efficiency of the proposed seesaw system in comparison with other two mentioned groups, first, by finite element modeling, verified by experimental results, the initial and secondary stiffness values as well as the yielding and ultimate strengths of the MCYPEDs have been obtained to be modeled by multi-linear plastic springs in the seesaw buildings. Then, a series of NLTHA have been performed on the three groups of buildings by using a set of selected earthquakes. The compared responses include roof displacement and acceleration, base shear, inter-story drift and finally plastic hinges (PHs) formed in the building’s structures. Results show that the proposed seesaw building equipped with MCYPEDs not only results in lower seismic demand, similar to base isolation system, but also leads to remarkable energy dissipation capacity in the building structure at base level, so that the building structure remains basically elastic, and does not need any major repair work, even after large earthquakes, contrary to the conventional building which need to be demolished after the earthquake.

The equivalent viscous damping is a key parameter in the prediction of the maximum nonlinear response. Damping constitutes a major source of uncertainty in dynamic analysis. This paper studies the effect of using viscous damping, on the reduction of the seismic responses of reinforced concrete RC frame buildings modeled as three-dimensional multi degree of freedom (MDOF) systems, and the use of nonlinear time history analysis as a method of visualized behavior of buildings in the elastic and inelastic range. This study focuses on the implications of the available modeling options on analysis. This article illustrates the effect of using the initial or tangent stiffness in Rayleigh damping in analysis of structures. Correspondingly, this work is also concerned with the estimation of Rayleigh, mass-proportional or stiffness-proportional damping on engineering demand parameters (EDPs). As a result of a series of considerations, a damping modeling solution for nonlinear time history analysis (NLTHA) was carried out to compute the damage index. The application example is a building designed according to reinforced concrete code BAEL 91 and Algerian seismic code RPA 99/Version 2003 under seven earthquake excitations. The simulations demonstrated the accuracy and effectiveness of the proposed method to account for all of the above effects. RESUMEN El amortiguamiento viscoso equivalente es un parámetro clave en la predicción de la respuesta máxima no lineal. La amortiguación constituye una fuente importante de incertidumbre en el análisis dinámico. Este artículo estudia el efecto del uso de la amortiguación viscosa, en la reducción de las respuestas sísmicas de los edificios de estructuras de concreto reforzado con hormigón reforzado modeladas como sistemas tridimensionales de múltiples grados de libertad, y el uso del análisis de historia de tiempo no lineal como un método de comportamiento visualizado de Construcciones en la gama elástica e inelástica. Este estudio se centra en las implicaciones de las opciones de modelado disponibles en el análisis. Además, este artículo ilustra el efecto del uso de la rigidez inicial o tangente en la amortiguación de Rayleigh en el análisis de estructuras. Este trabajo también se ocupa de la estimación de Rayleigh, la amortiguación proporcional a la masa o la rigidez proporcional en los parámetros de demanda de ingeniería. Como resultado de una serie de consideraciones, se llevó a cabo una solución de modelado de amortiguamiento para el análisis de historial de tiempo no lineal para calcular el índice de daño. El ejemplo de aplicación es un edificio diseñado de acuerdo con el código de hormigón armado BAEL91 y el código sísmico argelino RPA99/2003 bajo siete excitaciones de terremoto. Las simulaciones demostraron la precisión y la eficacia del método propuesto.

Normally, Laminated Rubber Bearing Pads (LRBPs) are directly placed between girders and piers and their role is to provide the bridge span with horizontal movement, and to transmit the gravity loads from the deck to the piers. Although not designed for seismic loads, they can act as a fuse, partially isolating the substructure from the superstructure and keeping the piers intact during earthquakes. However, recent investigations show that large relative displacement of superstructure against substructure caused by sliding at bearing (sliding between girders and LRBPs) can cause expansion joint failure or even bridge span collapse. Accordingly, proper restrainers should be selected to prevent large displacement. Among all types of restrainers, viscous dampers as passive energy dissipation devices have shown a great capacity in damping earthquake energy. This study investigates the effectiveness of a VD-LRBP system, a viscous damper in conjunction with LRBPs, in dissipating energy and reducing the displacement of the superstructure with reference to the substructure caused by sliding at bearing during a seismic event. A Finite Element (FE) model was first developed and validated using available experimental and numerical results. With the validated model, a 3D Nonlinear Time History Analysis (NTHA) was conducted on a reinforced concrete bridge model under various records of earthquakes using OpenSees, an open-source finite element software. The relative displacement histories were recorded for the bridge in two cases: 1- with only LRBPs and 2- with viscous dampers and LRBPs (VD-LRBP system). The results of this study show that applying viscous dampers can reduce the relative displacement of the superstructure with reference to the substructure for up to 60 percent. As importantly, it can also reduce the residual displacement after the earthquake to near zero.

Pushover analysis has become an effective tool for seismic design of high-rise buildings under severe earthquakes. However, the applicability of traditional pushover analysis is often questioned for long-span structures due to their complex dynamic characteristics. In this paper, pushover analysis was adopted to determine the seismic behavior of a long-span steel truss structure under severe earthquakes. Load distributions were determined based on the fundamental modes for vertical and horizontal earthquakes respectively. Pushover curves were obtained by nonlinear static analysis. Target displacements were determined with capacity spectrum method. The maximum displacements and plastic hinge distributions determined by traditional pushover analysis agreed well with those by nonlinear time history analysis for both horizontal and vertical earthquake actions. It was then concluded that the seismic behavior of this kind of long-span steel truss structures can be evaluated by traditional pushover analysis accurately enough for practical design purpose.

This paper presents the seismic analytic fragility curve of soil nail wall structures. The numerical modeling procedure of the soil nail wall is presented and discussed in detail. Nonlinear elements have been used to provide an accurate finite element modeling of the soil nail wall. The effect of different soil modeling approaches is studied. Detailed procedures to select an efficient intensity measure are presented. Analytical fragility curves for the different performance levels of the soil nail wall are developed. Detailed techniques have been used to generate accurate soil modeling, such as the Mohr-Coulomb model (MC), Hardening Soil model (HS), and Hardening Soil model with Stiffness effect from small strains (HSS), and these are studied. Incremental dynamic analysis (IDA) is implemented to capture the response of the wall from linear to nonlinear levels. The efficiency of the two common intensity measures is studied (PGA and Sa(T1,5%)). It has been demonstrated that HSS and HS models are more reliable techniques for soil modeling. Two common intensity measures are studied, and the efficiency and the sufficiency of them are compared. It has been suggested that Sa(T1,5%) is a more efficient intensity measure than PGA for soil nail structures due to less depression in the IDA results. Different performance levels were defined to develop analytical fragility curves for different damage states.

Inelastic dynamic analyses were carried out using 3D and 2D models to predict the mean seismic response of four-span reinforced concrete (RC) bridges considering directionality effects. Two averaging methods, including an advanced method considering displacement direction, were used for the prediction of the mean responses to account for different incident angles of ground motion records. A method was developed to predict the variability of the mean displacement predictions due to variability in the incident angles of the records for different averaging methods. When the concepts of averaging in different directions were used, significantly different predictions were obtained for the directionality effects. The accuracy of the results obtained using 2D and 3D analyses with and without the application of the combination rules for the prediction of the mean seismic demands considering the incident angle of the records was investigated. The predictions from different methods to account for the records incident angles were evaluated probabilistically. Recommendations were made for the use of the combination rules to account for the directivity effects of the records and to predict the actual maximum displacement, referred to as the maximum radial displacement.

In this study, the effects of pounding on seismic behavior of mid-rise reinforced concrete (RC) adjacent buildings with insufficient separation distance were investigated. 5, 8, 10, 13 and 15-storey RC building models were created to represent mid-rise buildings. The nonlinear behavior properties of these models are reflected by plastic hinges defined at the column and beam ends. The buildings are modeled as a three dimensional (3D) column-beam frame system. Adjacent building models are derived, which are connected from floor to floor level using Kelvin contact elements. Total of 30 different adjacent building models were created with the use of buildings having different number of floors. The “0” m gaps reflect inadequate separation distance between adjacent buildings while the “5” m gap is used for the reference building without collision. In order to investigate the pounding effects between adjacent buildings, 22 real acceleration records compatible with TBEC-2018 were selected and scaled. Total of 660 3D nonlinear time history analyses were carried out and the roof displacement demands obtained from these analyses were compared for collision and without collision cases The outcomes of this study show that significant changes may occur in the building displacement demands due to the collision of the mid-rise RC neighboring buildings with insufficient seismic gap. Based on the findings obtained on significant number of adjacent building pairs with different period ratios, the displacement amplification factors (β) are proposed for the mid-rise RC buildings., Bu çalışmada, yetersiz derz mesafesine sahip orta yükseklikteki betonarme komşu binaların sismik etkiler altındaki çekiçleme davranışları incelenmiştir. Orta yükseklikteki binaların temsil edilebilmesi için 5, 8, 10, 13 ve 15 katlı betonarme bina modelleri oluşturulmuştur. Bu modellerin doğrusal elastik olmayan davranış özellikleri kolon ve kiriş uçlarına tanımlanan plastik mafsallar ile yansıtılmıştır. Doğrusal olmayan bina modelleri üç boyutlu (3B) kolonkiriş çerçeve sistemi olarak modellenmiştir. Kelvin birleşim elemanları kullanılarak döşemeden döşemeye bağlanan ikili bina modelleri türetilmiştir. Kat adetleri farklı olan binaların kullanımı ile birlikte toplam 30 adet farklı ikili model oluşturulmuştur. Çarpışmanın görülmediği ikili modellerde 5 m boşluk bırakılırken, çarpışmanın görüldüğü modellerde ise 0 m derz mesafesi seçilmiştir. Bu ikili binalar arasındaki çekiçleme etkilerinin araştırılabilmesi için TBDY-2018 ile uyumlu 22 adet gerçek ivme kaydı seçilerek ölçeklendirilmiştir. Ölçeklendirilen ivme kayıtları 30 adet ikili modele uygulanarak toplam 660 adet zaman tanım alanında dinamik analiz gerçekleştirilmiştir. Analizlerden elde edilen tepe deplasman talepleri, çarpışmalı ve çarpışmasız durumlar için kıyaslanmıştır. Çalışma sonucunda, komşu binaların çarpışması sonucu yapı taleplerinde ciddi değişimler görülmüştür. Komşu binaların periyot oranlarına bağlı olarak çekiçleme etkisi ile değişen yapı talepleri için deplasman büyütme faktörleri (β) önerilmiştir.

This study aims to investigate the determination of seismic separation gap of adjacent low and mid-rise reinforced concrete (RC) buildings with no structural irregularity using nonlinear time history analysis. The low and mid-rise RC buildings were reflected using 3, 4, 5, 6, 7, 8, 9 and 10-story buildings designed per 2018 Turkish Building Earthquake Code (TBEC-2018). Beam and column elements are modeled as nonlinear frame elements with lumped plasticity by defining plastic hinges at both ends of beams and columns. The adjacent three-dimensional (3D) building models are connected to each other by link elements at the floor levels. 1232 nonlinear dynamic (time history) analyses were performed using 56 different building pairs and 11 different earthquake record pairs (22 records) compatible with TBEC-2018 to obtain the required seismic gap distances. The distances necessary to avoid pounding obtained from the analyses were compared with the minimum seismic gap requirements of the current earthquake codes, provisions (Eurocode-8, ASCE 7-16 and TBEC-2018) and several proposed methods (ABS, SRSS and DDC) in the literature. The outcomes indicate that the ASCE 7-16 and EC-8 significantly overestimate the required seismic gap distances for the buildings with similar dynamic characteristics while they provide reasonable estimates for the buildings with significantly different dynamic characteristics. However, the TBEC-2018 requirements are insufficient for the neighboring building period ratios greater than 1.25. Although both the ASCE 7-16 and EC-8 requirements are acceptable for the design of new buildings as being on safe side, they are not useful for the evaluation of existing buildings. Two different simple approaches were proposed to estimate the required seismic gap distances between neighboring buildings. The first approach requires linear static analysis of the buildings subjected to the reduced seismic design forces while the second simplified approach does not need any analysis. The proposed equations in this study are simple and useful for the evaluation of existing low and mid-rise RC buildings with no structural irregularity. Besides, their estimates are acceptable for the design purposes.

This study introduces a multiple-input convolutional neural network (MI-CNN) model for the seismic damage assessment of regional buildings. First, ground motion sequences together with building attribute data are adopted as inputs of the proposed MI-CNN model. Second, the prediction accuracy of MI-CNN model is discussed comprehensively for different scenarios. The overall prediction accuracy is 79.7%, and the prediction accuracies for all scenarios are above 77%, indicating a good prediction performance of the proposed method. The computation efficiency of the proposed method is 340 times faster than that of the nonlinear multi-degree-of-freedom shear model using time history analysis. Third, a case study is conducted for reinforced concrete (RC) frame buildings in Shenzhen city, and two seismic scenarios (i.e., M6.5 and M7.5) are studied for the area. The simulation results of the area indicate a good agreement between the MI-CNN model and the benchmark model. The outcomes of this study are expected to provide a useful reference for timely emergency response and disaster relief after earthquakes.

In seismic codes, the force strength reduction factor is proposed to transform elastic to inelastic strength. The ductility reduction factor, R μ , plays a key role on R factor if no overstrength is present. The R μ is determined by SDOF systems. But the higher mode (HM) and Multi-Degree-of-Freedom (MDOF) effects need to be considered to extract the R factor . These effects are studied by proposing α v-MDOF via at least 1764 Nonlinear dynamic Analysis of 2D-frames. Also a sensitivity study has been performed on R μ and α v-MDOF . Results obtained from studies conducted on the frames, indicate that HM and MDOF effects have a considerable influence on the base shear. Also the α v-MDOF is typically higher than unity both for ordinary and for near-field earthquakes and it is affected by period, span number and ductility level. These effects are remarkable for near-field motions. Finally, a simplified practical expression is proposed to estimate the α v-MDOF .

Bu çalışmada, kat içinde farklı oran ve düzende yerleştirilen dolgu duvarların betonarme binaların sismik davranışlarına olan etkileri araştırılmıştır. Türkiye Bina Deprem Yönetmeliği (TBDY-2018)'ne uygun olarak tasarımı gerçekleştirilen binaların performansları zaman tanım alanında doğrusal olmayan analiz yöntemiyle tespit edilmiştir. Analizler için 11 adet deprem kaydı, yakın ve uzak fay etkileri, depremlerin büyüklüğü, zemin cinsi ve Ülkemizin faylanma mekanizması gibi parametreler dikkate alınarak seçilmiştir. Seçilen ivme kayıtları, basit ölçeklendirme yöntemi kullanılarak TBDY-2018'de verilen yatay elastik tasarım spektrumuyla uyumlu olacak şekilde ölçeklendirilmiştir. Analizlerde 5 farklı oranda dolgu duvar dikkate alınmıştır. Bu dolgu duvarlar diyagonal (eşdeğer) basınç çubuğu olarak analizlerde dikkate alınmıştır. Binanın sonlu eleman modelinde SAP2000, kesit analizlerinde ise RESPONSE2000 programı kullanılmıştır. Analizler sonucunda, her bir dolgu duvar oranı için binalardan elde edilen mod şekilleri, titreşim periyot değerleri, göreli kat ötelemesi oranları ve bina performans seviyeleri karşılaştırmalı olarak sunulmuştur., In this study, the effects of infill walls, which are placed in different ratios and configurations, on the seismic behaviors of reinforced concrete buildings are investigated. The performance levels of the buildings which are designed according to Turkish Building Earthquake Code (TBEC-2018) are determined by using nonlinear time history analysis. For the nonlinear analysis, 11 ground motion records are selected by considering several parameters such as near and far fault effects, the magnitude of earthquakes, soil type and faulting mechanism. The selected ground motion records are scaled by using simple scaling method accordance with the horizontal elastic design spectrum which is defined in TBEC-2018. In the analyses, 5 different infill wall ratios and configurations are taken into consideration and the infill walls are modeled as equivalent compression strut. The SAP2000 program and RESPONSE2000 program are used for the finite element models of the structures and cross-section analysis, respectively. As a result of the analysis, mode shapes, natural period values, interstory drift ratios and building performance levels obtained for the different infill walls ratios are presented comparatively.

The increase in population especially in third world countries demands taller, more flexible, and lighter buildings. Most of these countries are subjected to a high risk of earthquakes, which requires more control of building seismic response. However, several techniques exist to minimize the vibrations induced by an earthquake shock. This paper will discuss the effectiveness of using friction dampers as a passive dissipative device and proposes some design optimization of the number and position of dampers in the building. Friction dampers offer a supplemental damping in conjunction with appropriate stiffness, offering an innovative and attractive solution for the seismic response control of tall structures in risky areas. The originality of this work is in the detailed seismic study of an asymmetric reinforced concrete (RC) building, located in a risky seismic zone and using real earthquake seismic waves. The seismic response of this dissipative structural method is compared with the response of the conventional method (shear wall system) for the high rise building. To accomplish this objective, a nonlinear modal time history analysis using the El Centro earthquake record for a 40‐storey RC high rise building, is performed with four different damper type formats using ETABS software. To illustrate the response improvement by dampers, storey accelerations, storey displacements, base shear forces, and storey drifts are compared with a conventional fixed base system (shear wall system) for the same building. Results show that using an optimum position and number of dampers, a tall building can remain operational during a seism.

Structural fuses and rocking system are used in order to reduce the building response to earthquakes and damage guidance. In the proposed seesaw motion system, which is similar to the rocking system, the building columns, in top of the foundation, have been removed and a central support and structural fuses are used around the building instead of them. The main purpose of creating this system is that the structural components remain elastic during the earthquake and nonlinear deformations occur in circumferential structural fuses it means that, it is possible to replace damaged fuses after the earthquake and exploit the building in a short time and at a lower cost than the construction cost of the whole building. In this research, the specification of a kind of structural fuse have been investigated and its application in the building with a seesaw system is studied under the influence of the near-field earthquake. After reviewing the fuses, it was observed that, the maximum absolute acceleration of roof and the base shear are significantly reduced in this system; however, the relative drift of floors in some buildings has increased but is lower than the permitted limit.

Uncertainty quantification is an important issue in the seismic fragility analysis of bridge type structures. However, the influence of different sources of uncertainty on the seismic fragility of the system is commonly overlooked due to the costly re-evaluation of numerical model simulations. This paper aims to present a framework for the seismic fragility analysis of reinforced concrete highway bridges, where a data-driven metamodel is developed to approximate the structural response to structural and ground motion uncertainties. The proposed framework to generate fragility curves shows its efficiency while using a few finite element simulations and accounting for various modeling uncertainties influencing the bridge seismic fragility. In this respect, a class of single-bent bridges available in the literature is taken as a case study, whose three-dimensional finite element model is established by the OpenSees software framework. Twenty near-source records from different sources are selected and the Latin hypercube method is applied for generating the random samples of modeling and ground motion parameters. The Kriging metamodel is then driven on the structural response obtained from nonlinear time history analyses. Component fragility curves of the reinforced concrete pier column are derived for different damage states using the Kriging metamodel whose parameters are established considering different modeling parameters generated by Monte Carlo simulations. The results demonstrate the efficiency of the proposed framework in interpolating the structural response and deriving the fragility curve of the case study with any input conditions of the random variables.

This research evaluates the effectiveness of using a roller-type base isolation device with tensile strength in reducing the dynamic response of industrial steel storage racks. These were subjected to a seismic input acting separately in both directions of the structure. The seismic record obtained from the earthquake that occurred in Llolleo, Chile, on 3 March 1985, was used as input. This earthquake was scaled in the frequency domain, adjusting its response spectrum to coincide with the design spectrum required by NCh2745. In the calculations of this spectrum, the most hazardous seismic zone (zone 3) and soft soil (soil III) that amplifies the effect of the low frequencies of the earthquake were considered. These frequencies are the ones that have the most affect on flexible structures such as high racks and systems with base isolation. Numerical time-history analyses were performed in fixed base racks and base isolation racks. In both cases, the models include semi-rigid connections with capacity for plastic deformation and energy dissipation. Parametric analyses were carried out considering the most relevant variables, using an algorithm programmed in MATLAB software. The maximum relative displacement, maximum basal shear load, and maximum absolute floor acceleration were considered as responses of interest. The results showed the effectiveness of using the base isolation device by reducing the absolute accelerations between approximately 75% and 90%, compared to the same fixed rack at its base. This makes it possible to reduce the vulnerability of the stored load to overturn under the action of a severe earthquake.

In this study, we try to compare different intensity measures for evaluating nonlinear response of bridge structure. This paper presents seismic analytic fragility of a three-span concrete girder highway bridge. A complete detail of bridge modeling parameters and also its verification has been presented. Fragility function considers the relationship of intensities of the ground motion and probability of exceeding certain state of damage. Incremental dynamic analysis (IDA) has been subjected to the bridge from medium to strong ground motions. A suite of 20 earthquake ground motions with different range of PGAs are used in nonlinear dynamic analysis of the bridge. Complete sensitive analyses have been done on the response of bridge and also efficiency and practically of them are studied to obtain a proficient intensity measure for these types of structure by considering its sensitivity to the period of the bridge. Three dimensional finite element (FE) model of the bridge is developed and analyzed. The numerical results show that the bridge response is very sensitive to the earthquake ground motions when PGA and Sa (Ti, 5%) are used as intensity measure (IM) and also indicated that the failure probability of the bridge system is dominated by the bridge piers.

Experimental tests have shown that unreinforced masonry (URM) infill walls are affected by simultaneous loading in their in-plane and out-of-plane directions, but there have been few attempts to represent this interaction in nonlinear time history analysis of reinforced concrete (RC) buildings with URM infill walls. In this paper, a recently proposed macro-model that accounts for this interaction is applied to the seismic analysis of RC framed structures with URM infill walls representative of Mediterranean building stock and practices. Two RC framed structures that are representative of low and mid-rise residential buildings are analysed with a suite of a bidirectional ground motions, scaled to three different intensities. During the analyses, the in-plane/out-of-plane interaction is monitored, showing that cracking of the infills occurs predominantly by in-plane actions, while failure occurs due to a combination of in-plane and out-of-plane displacements, with the out-of-plane component usually playing the dominant role. Along the frame height, the bottom storeys are generally the most damaged, especially where thin infill walls are used. These results are consistent with observations of damage to URM infill walls in similar buildings during recent earthquakes.

Building damage level due to earthquake is widely related to the features of the record which consist of many parameters. Although it is difficult to realize the ground motion parameters that have high influence on building performance, the vital parameters that may cause building damage may be considered as PGA, PGV, PGD, PGA/PGV, PGA/PGD, PGV/PGD, frequency content, effective time duration, fault line distance of the earthquake. In this study, these parameters were selected in order to determine more effective parameter on the building performance. For this aim, a model of Artificial Neural Network (ANN) algorithm was used as an efficient tool consisting of the obtained results of nonlinear time history analysis of samples. The 200 records, produced by strike-slip fault mechanism, were selected for the soil type C (Z3) according to the Turkish Earthquake Code [1]. A six story R/C frame building, with three various spans were analyzed via IDARC-2D software. The Park and Ang damage index was used in order to evaluate the vulnerability of buildings. The results showed that the ANN can be able to determine the effective parameters of ground motions with sufficient correlation. Also the most and least significant parameters of earthquake are discussed based on the results of the analysis. The file in this item is the publisher version (published version) of the article.

The article presents experimental research and comparison of two performance-based seismic evaluation methods: nonlinear static procedure (NSP) / pushover analysis (PoA) and nonlinear time history analysis. It is established that nonlinear static procedure is good enough for prediction of plastic hinges localization, but difference between methods results is more than 15 % with a lack of seismic resistance.

In recent years, nonlinear calculation methods can be easily carried out by means of developing computer technologies. In this way, comparisons of the nonlinear methods have started to increase rapidly and more studies are carried out on regular and irregular buildings. However, it is most important to compare consistency of the methods on buildings. In this study, most common nonlinear static (pushover) and nonlinear dynamic analysis (time history analysis) methods were compared on an asymmetric planned reinforced concrete (R/C) building. Building having horizontal and vertical irregularities was 5-story. Analyses were carried out by using SAP2000 program. The results are discussed in terms of base shear, lateral displacements and top displacement ratios.

Palancı, Mehmet (Arel Author), In this study, seismic assessment of one story precast industrial buildings that constitute majority of industrial facilities in Turkey was investigated by using probabilistic approach. For this purpose, 98 one story precast industrial buildings that represent general structural aspects of precast industrial building stock of Turkey were used. Strength and deformation capacities of buildings were determined by inelastic methods and seismic demands were calculated by nonlinear time history analyses. In order to represent low, moderate and high intensity earthquake levels, more than 300 ground motion records were used. Fragility curves of precast buildings were then constructed by comparing the displacement capacities and seismic demands. Peak ground velocity was used as ground motion parameter to construct analytical fragility curves. Assessment of inventory buildings was performed by considering the effect of lateral strength ratio, stiffness and ductility parameters. Observations have shown that probabilities of lower damage levels (slight and moderate) are almost similar and they are independent from structural parameters considered. It was also observed that ductility and lateral strength ratios (Vt/W) have significant effect on seismic fragilities of precast industrial buildings at higher damage levels. Based on the observations, building stock was classified in three groups. Results have shown that strength and ductility based classification of existing precast industrial buildings is quite effective and it can be used as an important tool for the seismic assessment studies of one story precast industrial buildings.

This paper aims to observe effects of fluid-structure-soil interactions on the response modification coefficient of elevated concrete tanks with frame and shaft supporting systems. Because of weaknesses and failures of elevated tanks that have been reported in recent earthquakes and importance of optimum and resistant design and also better seismic performance of these structures, it is essential to investigate on the response modification coefficient of elevated concrete tanks. In this paper, the response modification coefficient has been evaluated by using the numerical modeling. The method of research is a case study. The models have been subjected to an ensemble of important earthquake ground motions. The effects of soilstructure interactions and fluid-structure interactions on seismic behavior of the elevated concrete tanks have been modeled by the equivalent springs and Housner’s method, respectively. Dynamic response of the elevated tanks has been considered by using the nonlinear time history analysis and the discrete plastic hinge approach. Finally, the effects of fluid-structure-soil interactions on the response modification coefficient of the elevated concrete tanks have been discussed by considering results of the analyses. It has been concluded that the codes may underestimate base seismic forces for some seismic regions and some subsoil classes.

This study aims to evaluate seismic performance of existing low and mid-rise reinforced concrete buildings by comparing their displacement capacities and displacement demands under selected ground motions experienced in Turkey as well as demand spectrum provided in 2007 Turkish Earthquake Code for design earthquake with 10% probability of exceedance in 50 years for soil class Z3. It should be noted that typical residential buildings are designed according to demand spectrum of 10% probability of exceedance in 50 years. Three RC building sets as 2-, 4- and 7-story, are selected to represent reference low-and mid-rise buildings located in the high seismicity region of Turkey. The selected buildings are typical beam-column RC frame buildings with no shear walls. The outcomes of detailed field and archive investigation including approximately 500 real residential RC buildings established building models to reflect existing building stock. Total of 72 3-D building models are constructed from the reference buildings to include the effects of some properties such as structural irregularities, concrete strength, seismic codes, structural deficiencies, transverse reinforcement detailing, and number of story on seismic performance of low and mid-rise RC buildings. Capacity curves of building sets are obtained by nonlinear static analyses conducted in two principal directions, resulting in 144 models. The inelastic dynamic characteristics are represented by "equivalent" Single-Degree-of- Freedom (ESDOF) systems using obtained capacity curves of buildings. Nonlinear time history analysis is used to estimate displacement demands of representative building models idealized with (ESDOF) systems subjected to the selected ground motion records from past earthquakes in Turkey. The results show that the significant number of pre-modern code 4- and 7-story buildings exceeds LS performance level while the modern code 4- and 7-story buildings have better performances. The findings obviously indicate the existence of destructive earthquakes especially for 4- and 7-story buildings. Significant improvements in the performance of the buildings per modern code are also obvious in the study. Almost one third of pre-modern code buildings is exceeding LS level during records in the past earthquakes. This observation also supports the building damages experienced in the past earthquake events in Turkey. � 2016 Techno-Press, Ltd.

Modern performance-based design methods require ways to determine the factual behavior of structures subjected to earthquakes. Drift ratio demands are important measures of structural and/or non-structural damage of the structures in performance-based design. In this study, global drift ratio and interstory drift ratio demands, obtained by nonlinear time history analysis of three generic RC frames using code-compatible ground motion record sets, are statistically evaluated. Several ground motion record sets compatible with elastic design spectra defined for the local soil classes in Turkish Earthquake Code are used for the analyses. Variation of the drift ratio demands obtained from ground motion records in the sets and difference between the mean of drift ratio demands calculated for ground motion sets are evaluated. The results of the study indicate that i) variation of maximum drift ratio demands in the sets were high; ii) different drift ratio demands are calculated using different ground motion record sets although they are compatible with the same design spectra; iii) the effect of variability due to random causes on the total variability of drift ratio demands is much larger than the effect of variability due to differences between the mean of ground motion record sets; iv) global and interstory drift ratio demands obtained for different ground motion record sets can be accepted as simply random samples of the same population at %95 confidence level. The results are valid for all the generic frames and local soil classes considered in this study. Copyright © 2016 Techno-Press, Ltd..

This study aims to present nonlinear time history analysis results of double leaf cavity wall (DLCW) reinforced concrete structure exposed to shake table tests. Simulation of the model was done by a Finite Element (FE) program. Shake table experiment was performed at the National Civil Engineering Laboratory in Lisbon, Portugal. The results of the experiment were compared with numeric DLCW model and numeric model of reinforced concrete structure with unreinforced masonry wall (URM). Both DLCW and URM models have two bays and two stories. Dimensions of the tested structure and finite element models are 1:1.5 scaled according to Cauchy Froude similitude law. The URM model has no experimental results but the purpose is to compare their performance level with the DLCW model. Results of the analysis were compared with experimental response and were evaluated according to ASCE/SEI 41-06 code.

This paper is intended to evaluate the seismic performance of a twelve-story reinforced concrete moment-resisting frame structure with shear walls using 3D finite element models according to such seismic design regulations as Federal Emergency Management Agency (FEMA) guideline and seismic building codes including Los Angeles Tall Building Structural Design Council (LATBSDC) code. The structure is located in Seismic Zone 4, considered the highest-seismic-risk classification established by the U.S. Geological Survey. 3D finite element model was created in commercially available finite element software. As part of the seismic performance evaluation, two standard approaches for the structure seismic analysis were used, response spectrum analysis and nonlinear time-history analysis. Both approaches were used to compute inter-story drift ratios of the structure. Seismic fragility curves for each floor of the structure were generated using the ratios from the time history analysis with the FEMA guideline so as to evaluate their seismic vulnerability. The ratios from both approaches were compared to FEMA and LATBSDC limits. The findings revealed that the floor-level fragility mostly decreased for all the FEMA performance levels with an increase in height and the ratios from both approaches mostly satisfied the codified limits.

In this paper, it is aimed to determine the earthquake effects on cable-stayed bridge isolated by single concave friction pendulum bearings (SCFP). In this context, Manavgat cable-stayed bridge is selected as a numerical application. The selected bridge has 202. m composite deck and 42. m steel tower. 3D finite element models (FEM) of the base isolated and non-isolated bridge are modeled by using SAP2000. Three different earthquakes which are 11 December 1999 Düzce, 23 November 2011 Van and 13 March 1992 Erzincan earthquakes are subjected to the 3D FEM models in order to determine the seismic behavior of the bridges. BOL-090 and BOL-000; ERCIS-EW and ERCIS-NS; ERZ-NS and ERZ-EW components of ground motions obtained from PEER and AFAD are applied to the bridges at the longitudinal and transverse directions, respectively. Nonlinear time history analysis is executed to determine the dynamic responses of the bridge. Comparison of dynamic behavior of isolated and non-isolated bridge with and without the SCFP bearings under three different earthquake motions has been conducted. The results obtained from analyses of 3D FEM of the bridge are presented by graphics and tables in detail. It is seen that using of isolation system reduces the destructive effects of earthquakes on the bridge. © 2014 Elsevier Ltd.

This work proposes design energy spectra in terms of an equivalent velocity, intended for regions with design peak acceleration 0.3 g or higher. These spectra were derived through linear and nonlinear dynamic analyses on a number of selected Turkish strong ground motion records. In the long and mid period ranges the analyses are linear, given the relative insensitivity of the spectra to structural parameters other than the fundamental period; conversely, in the short period range, the spectra are more sensitive to the structural parameters and, hence, nonlinear analyses are required. The selected records are classified in eight groups with respect to soil type (stiff or soft soil), the severity of the earthquake in terms of surface magnitude $$M _\mathrm{s} (M_\mathrm{s} \le $$ 5.5 and $$M _\mathrm{s} >$$ 5.5) and the relevance of the near-source effects (impulsive or vibratory). For each of these groups, median and characteristic spectra are proposed; such levels would respectively correspond to 50 and 95 % percentiles. These spectra have an initial linear growing branch in the short period range, a horizontal branch in the mid period range and a descending branch in the long period range. Empirical criteria for estimating the hysteretic energy from the input energy are suggested. The proposed design spectra are compared with those obtained from other studies.

In Latin America there is an urgent need for housing; thus, during the last few years a relevant number of mid-height buildings (usually, up to five stories) with thin RC shear–walls have been constructed for low-cost dwellings in Bolivia, Colombia, Ecuador, Mexico, Peru, Venezuela, and other countries located in seismic-prone regions. These walls are 10 cm thick and their reinforcement consists mainly of a single layer of welded wire mesh. This construction technology offers two main advantages: economy and rapidity of construction. These buildings do not fulfill the international seismic codes but some national regulations are less demanding, not preventing the use of thin bearing walls. These buildings might be vulnerable to earthquakes because of their low ductility, the insufficiency of the experimental information, the absence of observed damages and, in some cases, poor construction quality. This work describes the initial steps of a wider research aiming at providing reliable seismic design guidelines for thin-wall buildings; the initial objectives are analyzing the seismic performance of these buildings, proposing preliminary design criteria and identifying further research needs. This research focuses on buildings located in Peru, being representative of the situations in the other countries. The vulnerability is numerically evaluated by push-over and nonlinear time history analyses; the structural parameters are obtained from available testing information. The obtained results show that the seismic strength of the analyzed buildings is insufficient; however, minor changes in the structural design might improve significantly their seismic performance. Cheap and easy-to-implement design recommendations are issued.

Over the last decade the amount of population injured by accident furniture overturning is increased and this trend is expected to continue. Non anchored body motion can be categorized in 6 basic types: rest, slide, rock, slide-rock, free flight and impact. The aim of this research is to analyze through numerical analysis the behavior of a free-standing rigid body during the phase of rocking motion under dynamic load. The model of free body rocking motion was proposed by G. W. Housner in 1963 first. Later a number of alternative models have been developed opportunely change the original assumption in order to and obtain more realistic results. In this research different models are compared with numerical simulations, using different excitation input and results are shown in the acceleration-frequency plane. These results confirmed the importance of the geometrical shape of the rigid block and the necessity to individuate the risk factors that can cause overturning phenomena. Nonlinear time history analysis using real earthquake floor motions recorded in a real time monitored building in California are used to simulate the behavior of a furniture located inside a multi-story building. Sensitivity analysis is performed in order to find the optimal location of the furniture inside the building. The research goal is to establish how to reduce the risk of overturning during an earthquake in real structures and to propose a simple and practical procedure to locate the risk area in the building where slender furniture can overturn. Prevention actions are proposed by changing the shape of the furniture, the friction coefficient or by using some appropriate devices

This paper investigates the response of nonstructural components in the presence of nonlinear behavior of the primary structure using floor response spectra method (FRS). The effect of several parameters such as initial natural frequency of the primary structure, natural frequency of the nonstructural components (subsystem), strength reduction factor and hysteretic model have been studied. A database of 164 registered ground acceleration time histories from the European Strong-Motion Database is used. Results are presented in terms of amplification factor and resonance factor. Amplification factor quantifies the effect of inelastic deformations of the primary structure on subsystem response. Resonance factor quantifies the variation of the subsystem response considering the primary structure acceleration. Obtained results differed from precedent studies, particularly for higher primary structure periods. Values of amplification factor are improved. Obtained results of resonance factor highlight an underestimation of peak values according to current design codes such as Eurocode 8. Therefore a new formulation is proposed.

The latest developments in the construction technologies and the materials facilitated the practicing engineers to go higher and energy-efficient buildings. However, the safety of the buildings and the residents has been an issue all the time. This is not an exception for the precast structures. The advantages of the precast elements are the quality assurance and the rapid erection on the site and challenged by the connection details and their performances during the extreme loading cases such as earthquakes. The utilization of a special mechanical connection of the precast members have been in the focus of the recent works in Istanbul Technical University (ITU-STEELAB). The prototypes of the proposed special connectors, called as cushion, were tested in STEELAB in order to determine the mechanical properties such as lateral and axial stiffness and the failure modes. Once the properties were determined, a hypothetical building of single story multi-bay slab type structure was modeled in the computer framework capable of substituting various parametric values into the model, processing and extracting the results for statistical analysis, SAMA. SAMA is developed based on the use of SAP 2000 OAPI functions called in MATLAB and Python scripts. In the hypothetical model, the cushions were modeled as link elements and placed between all the precast elements including foundation-cladding interface. Extensive non-linear time-history analysis was conducted to identify the damage localization by comparing the energy dissipation at each mechanical connector under ground motion records selected according to focal distance, site conditions and intensity. The preliminary results reveal that the cushions are effectively dissipating a significant amount of energy and mitigating the collapse of the precast elements. The more detailed conclusions will be discussed in the near future. Publisher's Version