scholarly journals A New Empirical Correlation for Estimation of EBF Steel Frame Behavior Factor under Near-Fault Earthquakes Using the Genetic Algorithm

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Seyed Abdonnabi Razavi ◽  
Navid Siahpolo ◽  
Mehdi Mahdavi Adeli
Keyword(s):  
Genetic Algorithm ◽  
Test Data ◽  
Mean Squared Error ◽  
Time History ◽  
Training Data ◽  
Geometrical Properties ◽  
Behavior Factor ◽  
Near Fault ◽  
Different Types ◽  
Near Fault Earthquakes

The most important feature of the behavior factor is that it allows the structural designer to be able to evaluate the structural seismic demand, using an elastic analysis, based on force-based principles quickly. In most seismic codes, this coefficient is merely dependent on the type of lateral resistance system and is introduced with a fixed number. However, there is a relationship between the behavior factor, ductility (performance level), structural geometric properties, and type of earthquake (near and far). In this paper, a new and accurate correlation is attempted to predict the behavior factor (q) of EBF steel frames, under near-fault earthquakes, using the genetic algorithm (GA). For this purpose, a databank consisting of 12960 data is created. To establish different geometrical properties of models, 3−, 6−, 9−, 12−, 15, and 20− story steel EBF frames were considered with 3 different types of link beam, 3 different types of column stiffness, and 3 different types of brace slenderness. Using nonlinear time history under 20 near-fault earthquake, all models were analyzed to reach 4 different performance levels. 6769 data were used as GA training data. Moreover, to validate the correlation, 2257 data were used as test data for calculating mean squared error (MSE) and correlation coefficient (R) between the predicted values of (q) and the real values. In addition, the MSE and R were calculated for correlation in the train and test data. Also, the comparison of the response of maximum inelastic displacement of 5 stories EBF from the proposed correlation and the mean inelastic time-history analysis confirms the accuracy of the estimate relationship.

scholarly journals An Optimal Approach of Adaptive Neuro -Fuzzy Inference System to Predict the Roof Ductility Demand of EBFs Subjected to Near-Fault Pulse-Like Ground Motions

2020 ◽  
Vol 5 (6) ◽  
pp. 1516-1537
Author(s):  
Seyed Abdonnabi Razavi ◽  
Navid Siahpolo ◽  
Mehdi Mahdavi Adeli
Keyword(s):  
Fuzzy Inference System ◽  
Fuzzy Inference ◽  
Time History ◽  
Training Data ◽  
Subtractive Clustering ◽  
Inference System ◽  
Geometrical Properties ◽  
Near Fault ◽  
Neuro Fuzzy ◽  
Intelligent Model

Careful estimation of global ductility will certainly lead to greater accuracy in the design of structural members. In this paper, a new and optimal intelligent model is proposed to predict the roof ductility (μR) of EBF steel frames exposed to the near-fault pulse-like earthquakes, using the Adaptive Neuro-Fuzzy Inference System (ANFIS). To achieve this goal, a databank consisting of 12960 data is created. To establish different geometrical properties of models, 3-,6-, 9-, 12-, 15, 20-stories, steel EBF frames are considered with 3 different types of link beam, column stiffness, and brace slenderness. All models are analysed to reach 4 different performance levels using nonlinear time history under 20 near-fault earthquakes. About 6769 data are applied as ANFIS training data. Subtractive clustering and Fuzzy C-Mean clustering (FCM) methods are applied to generate the purposed model. The results show that FCM provides more accurate outcomes. Moreover, to validate the model, 2257 data are applied (as test data) in order to calculate the correlation coefficient (R) and mean squared error (MSE) between the predicted values of (μR) and the real values. The results of correlation analysis show the high accuracy of the proposed intelligent model.

Optimal Placement of Viscous Dampers in the Water Pipeline Networks Subjected to Near-Fault Earthquakes Using Genetic Algorithm

2013 ◽  
Author(s):  
Seyed Kazem Sadat Shokouhi ◽  
Azam Dolatshah ◽  
Hamid Reza Vosoughifar ◽  
Yousef Rahnavard
Keyword(s):  
Genetic Algorithm ◽  
Critical Points ◽  
Seismic Waves ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Optimal Placement ◽  
Viscous Dampers ◽  
Pipeline Network ◽  
Near Fault ◽  
Water Pipeline

Experiences of previous earthquakes demonstrate that lifelines have no proper performance exposed to Near-Fault (NF) earthquakes. Due to considerable effects of NF earthquakes and recommendation of the related design codes such as FEMA, evaluating the effects of these earthquakes on the pipelines is so important. In this research, the optimal placement of the viscous dampers in the water pipeline network subjected to NF earthquakes has been studied using Genetic Algorithm (GA). For this purpose, the water pipeline network of a zone in Tehran city was selected as a case study and was modeled using the Finite Element Method (FEM). Then, the nonlinear time-history analysis was undertaken via seismic scaled records of NF earthquakes. The obtained results indicated the critical points of network which were failed due to applied seismic waves. However, due to economical and technical issues, the optimal damper placement at critical points is necessary; all of the mentioned points were considered for optimization procedure using GA. Then, the viscous dampers were installed in the acquired optimal points. Eventually, a statistical test demonstrated optimum performance of the water pipelines network equipped with viscous dampers under NF earthquakes.

Evaluation of Seismic Behavior on Steel Frames with TSW Semi-Rigid Connections under the Nonlinear Time History Analysis

2012 ◽  
Vol 166-169 ◽  
pp. 2083-2087
Author(s):  
Miaad Najdian ◽  
Mohsen Izadinia
Keyword(s):  
Time History ◽  
High Energy ◽  
Time History Analysis ◽  
Nonlinear Time History Analysis ◽  
Near Fault ◽  
Good Ability ◽  
History Analysis ◽  
Ductile Behavior ◽  
Near Fault Earthquakes ◽  
Nonlinear Time History

Movements of pulse shape and the high energy applied in short duration by the near fault earthquake, causes brittle fracture in rigid connections that during the Northridge 1994 and Kobe 1995 earthquakes was frequently seen. Rigid connections, which are generally welded due to lack of ductility, have low energy absorption capability. On the other hand semi-rigid connections have a ductile behavior and have a good ability to absorb energy. The purpose of this paper is analysis and compares the behaviors of “rigid” and “TSW semi-rigid” connections under the near fault earthquakes with nonlinear time history analysis by perform 3D software.

scholarly journals The Inflation Forecasting of Major Cities In East Kalimantan: A Comparison Of Holt-Winters And SARIMA Model

2021 ◽  
Vol 1 (2) ◽  
pp. 1-11
Author(s):  
Regi Muzio Ponziani
Keyword(s):  
Test Data ◽  
Mean Squared Error ◽  
Moving Average ◽  
Training Data ◽  
Sarima Model ◽  
East Kalimantan ◽  
Inflation Forecasting ◽  
Autoregressive Integrate Moving Average ◽  
Economic Nature ◽  
Sarima Models

This research aims to compare the performance of Holt Winters and Seasonal Autoregressive Integrate Moving Average (SARIMA) models in predicting inflation in Balikpapan and Samarinda, two biggest cities in East Kalimantan province. The importance of East Kalimantan province cannot be overstated since it has been declared as the venue for the capital of Indonesia. Hence, inflation prediction of the two cities will give valuable insights about the economic nature of the province for the country’s new capital. The data used in this study extended from January 2015 to September 2021. The data were divided into training and test data. The training data were used to model the time series equation using Holt winters and SARIMA models. Later, the models derived from training data were employed to produce forecasts. The forecasts were compared to the actual inflation data to determine the appropriate model for forecasting. Test data were from January 2015 to December 2020 and test data extended from January 2021 to September 2021. The result showed that Holt-Winters performed better than SARIMA in prediction inflation. The Root Mean Squared Error (RMSE) values are lower for Holt-Winters Exponential Smoothing for both cities. It also predicts better timing of cyclicality than SARIMA model.

Performance of Bridges Isolated with Sliding-Lead Rubber Bearings Subjected to Near-Fault Earthquakes

2020 ◽  
Vol 20 (02) ◽  
pp. 2050023 ◽  
Author(s):  
Wenzhi Zheng ◽  
Hao Wang ◽  
Hong Hao ◽  
Kaiming Bi ◽  
Huijun Shen
Keyword(s):  
Time History ◽  
Isolation System ◽  
Peak Displacement ◽  
Residual Displacement ◽  
Near Fault ◽  
Lead Rubber Bearing ◽  
Base Forces ◽  
Near Fault Earthquakes ◽  
Rubber Bearings ◽  
Nonlinear Time History

This paper investigates the seismic performance of bridges installed with a sliding-lead rubber bearing (LRB) isolation system subjected to near-fault earthquakes. A three-span continuous bridge isolated with sliding-LRB system is used as an example. Nonlinear time history analyses are conducted to investigate the sensitivity effects of isolation period, friction coefficient and sliding displacement limit on the bridge responses. The responses of the sliding-LRB system are compared with those of the conventional LRB system. The results show that the base forces of the piers can be reduced by employing proper friction coefficients. However, the residual displacement of the sliding-LRB system may be larger compared with that of the conventional LRB system. To overcome this disadvantage, an improved solution to reduce the residual displacement is proposed with its effectiveness investigated. It was also demonstrated that the residual displacement and peak displacement can be effectively reduced by employing the shape memory alloy devices in the sliding-LRB system without significantly increasing the base forces.

scholarly journals Effects of Near Fault and Far Fault Ground Motions on Nonlinear Dynamic Response and Seismic Improvement of Bridges

2018 ◽  
Vol 4 (6) ◽  
pp. 1456 ◽  
Author(s):  
Mohammad Hajali ◽  
Abdolrahim Jalali ◽  
Ahmad Maleki
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Relative Displacement ◽  
Near Fault ◽  
Acceleration Rate ◽  
Near Fault Earthquakes ◽  
Far Fault

In this study, the dynamic response of bridges to earthquakes near and far from the fault has been investigated. With respect to available data and showing the effects of key factors and variables, we have examined the bridge’s performance. Modeling a two-span concrete bridge in CSI Bridge software and ability of this bridge under strong ground motion to near and far from fault has been investigated. Nonlinear dynamic analysis of time history includes seven records of past earthquakes on models and it was observed that the amount of displacement in the near faults is much greater than the distances far from faults. Bridges designed by seismic separators provide an acceptable response to a far from fault. This means that in bridges using seismic separators, compared to bridges without seismic separators, Acceleration rate on deck, base shearing  and the relative displacement of the deck are decrease. This issue is not seen in the response of the bridges to the near faults. By investigating earthquakes near faults, it was observed that near-fault earthquakes exhibit more displacements than faults that are far from faults. These conditions can make seismic separators critical, so to prevent this conditions FDGM should be used to correct the response of these bridges. Based on these results, it can be said that the displacement near faults with forward directivity ground motion is greater than far from faults. So that by reducing the distance from the faults, the maximum value of the shearing and displacement of the deck will be greater.

Seismic Behavior Evaluation of Semi-Rigid Steel Frames with EEP Connections under the near-Fault Earthquakes

2012 ◽  
Vol 174-177 ◽  
pp. 561-565
Author(s):  
Miaad Najdian ◽  
Mohsen Izadinia
Keyword(s):  
Time History ◽  
The Other ◽  
Nonlinear Time History Analysis ◽  
Near Fault ◽  
Good Ability ◽  
History Analysis ◽  
Ductile Behavior ◽  
Near Fault Earthquakes ◽  
Nonlinear Time History ◽  
3D Software

Pulse shape motions and huge amount of energy applied in short duration by the near fault earthquake, cause brittle fracture in welded connections, which is widely observed in Kobe 1995 and Northridge 1994 earthquakes. Rigid connections, which are generally welded due to lack of ductility, have low energy absorption capability. On the other hand, Semi-rigid connections have a ductile behavior and have a good ability to absorb energy. The purpose of this paper is analysis and compares the behaviors of “rigid” and “EEP semi-rigid” connections in cases of “four bolt extended”, “eight bolt extended stiffened” and “eight bolt, four bolts wide, extended stiffened” under the near fault earthquakes with nonlinear time history analysis by perform 3D software. The results shown that the steel frame with “four bolt extended” semi-rigid connections have appropriate performance compared to the other frames.

Seismic Response of a Viaduct under near-Fault Earthquakes

2012 ◽  
Vol 166-169 ◽  
pp. 2368-2372
Author(s):  
Yan Jiang Chen ◽  
Yu Bo Zhang ◽  
Wei Ming Yan ◽  
Yong Li
Keyword(s):  
Dynamic Response ◽  
Seismic Response ◽  
Time History ◽  
Response Patterns ◽  
Structural Dynamic ◽  
Near Fault ◽  
Large Velocity ◽  
Time History Response ◽  
Near Fault Earthquakes ◽  
Periodic Components

Abundant long-periodic components endue near-fault earthquakes with large velocity pulses while the viaducts owe long periodic fundamental period. To explore the seismic response patterns of viaducts under near-fault earthquakes, the paper analyzed the time history response of a viaduct under near-fault seismograms including TCU 1063, TCU 065, El centro and Artificial wave via FEM software Civil. The analysis shows a significant boost in near-fault seismic response as the value of PGV/PGA increased accordingly, indicates that the near-fault pulse affects strongly on the structural dynamic response of the viaducts.

scholarly journals Effectiveness of modified pushover analysis procedure for the estimation of seismic demands of buildings subjected to near-fault ground motions having fling step

2013 ◽  
Vol 13 (6) ◽  
pp. 1579-1593 ◽  
Author(s):  
A. Mortezaei ◽  
H. R. Ronagh
Keyword(s):  
Ground Motions ◽  
Pushover Analysis ◽  
Time History ◽  
Building Structures ◽  
Seismic Demands ◽  
Near Fault ◽  
Load Pattern ◽  
Dynamic Time ◽  
Near Fault Earthquakes ◽  
Nonlinear Time History

Abstract. Near-fault ground motions with long-period pulses have been identified as being critical in the design of structures. These motions, which have caused severe damage in recent disastrous earthquakes, are characterized by a short-duration impulsive motion that transmits large amounts of energy into the structures at the beginning of the earthquake. In nearly all of the past near-fault earthquakes, significant higher mode contributions have been evident in building structures near the fault rupture, resulting in the migration of dynamic demands (i.e. drifts) from the lower to the upper stories. Due to this, the static nonlinear pushover analysis (which utilizes a load pattern proportional to the shape of the fundamental mode of vibration) may not produce accurate results when used in the analysis of structures subjected to near-fault ground motions. The objective of this paper is to improve the accuracy of the pushover method in these situations by introducing a new load pattern into the common pushover procedure. Several pushover analyses are performed for six existing reinforced concrete buildings that possess a variety of natural periods. Then, a comparison is made between the pushover analyses' results (with four new load patterns) and those of FEMA (Federal Emergency Management Agency)-356 with reference to nonlinear dynamic time-history analyses. The comparison shows that, generally, the proposed pushover method yields better results than all FEMA-356 pushover analysis procedures for all investigated response quantities and is a closer match to the nonlinear time-history responses. In general, the method is able to reproduce the essential response features providing a reasonable measure of the likely contribution of higher modes in all phases of the response.

scholarly journals Optimization of Genetic Algorithm Performance Using Naïve Bayes for Basis Path Generation

2017 ◽  
pp. 273-282 ◽  
Author(s):  
Achmad Arwan ◽  
Denny Sagita Rusdianto
Keyword(s):  
Genetic Algorithm ◽  
Test Data ◽  
Naive Bayes ◽  
Naïve Bayes ◽  
Training Data ◽  
Algorithm Performance ◽  
Accuracy Test ◽  
Path Testing ◽  
Independent Path ◽  
Number Of Iterations

Basis path testing is a method used to identify code defects. The determination of independent paths on basis path testing can be generated by using Genetic Algorithm. However, this method has a weakness. In example, the number of iterations can affect the emersion of basis path. When the iteration is low, it results in the incomplete path occurences.  Conversely, if iteration is plentiful resulting to path occurences, after a certain iteration, unfortunately, the result does not change. This study aims to perform the optimization of Genetic Algorithm performance for independent path determination by determining how many iteration levels match the characteristics of the code. The characteristics of the code used include Node, Edge, VG, NBD, and LOC. Moreover, Naïve Bayes is a method used to predict the exact number of iterations based on 17 selected code data into training data, and 16 data into test data. The result of system accuracy test is able to predict the exact iteration of 93.75% from 16 test data. Time-test results show that the new system was able to complete an independent search path being faster 15% than the old system.

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