Search results for: seismic data acquisition
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 25332

Search results for: seismic data acquisition

25242 Neuroplasticity in Language Acquisition in English as Foreign Language Classrooms

Authors: Sabitha Rahim

Abstract:

In the context of teaching vocabulary of English as Foreign Language (EFL), the confluence of memory and retention is one of the most significant factors in students' language acquisition. The progress of students engaged in foreign language acquisition is often stymied by vocabulary attrition, which leads to learners' lack of confidence and motivation. However, among other factors, little research has investigated the importance of neuroplasticity in Foreign Language acquisition and how underused neural pathways lead to the loss of plasticity, thereby affecting the learners’ vocabulary retention and motivation. This research explored the effect of enhancing vocabulary acquisition of EFL students in the Foundation Year at King Abdulaziz University through various methods and neuroplasticity exercises that reinforced their attention, motivation, and engagement. It analyzed the results to determine if stimulating the brain of EFL learners by various physical and mental activities led to the improvement in short and long term memory in vocabulary retention. The main data collection methods were student surveys, assessment records of teachers, student achievement test results, and students' follow-up interviews. A key implication of this research is for the institutions to consider having multiple varieties of student activities promoting brain plasticity within the classrooms as an effective tool for foreign language acquisition. Building awareness among the faculty and adapting the curriculum to include activities that promote brain plasticity ensures an enhanced learning environment and effective language acquisition in EFL classrooms.

Keywords: language acquisition, neural paths, neuroplasticity, vocabulary attrition

Procedia PDF Downloads 138
25241 Seismic Loss Assessment for Peruvian University Buildings with Simulated Fragility Functions

Authors: Jose Ruiz, Jose Velasquez, Holger Lovon

Abstract:

Peruvian university buildings are critical structures for which very little research about its seismic vulnerability is available. This paper develops a probabilistic methodology that predicts seismic loss for university buildings with simulated fragility functions. Two university buildings located in the city of Cusco were analyzed. Fragility functions were developed considering seismic and structural parameters uncertainty. The fragility functions were generated with the Latin Hypercube technique, an improved Montecarlo-based method, which optimizes the sampling of structural parameters and provides at least 100 reliable samples for every level of seismic demand. Concrete compressive strength, maximum concrete strain and yield stress of the reinforcing steel were considered as the key structural parameters. The seismic demand is defined by synthetic records which are compatible with the elastic Peruvian design spectrum. Acceleration records are scaled based on the peak ground acceleration on rigid soil (PGA) which goes from 0.05g to 1.00g. A total of 2000 structural models were considered to account for both structural and seismic variability. These functions represent the overall building behavior because they give rational information regarding damage ratios for defined levels of seismic demand. The university buildings show an expected Mean Damage Factor of 8.80% and 19.05%, respectively, for the 0.22g-PGA scenario, which was amplified by the soil type coefficient and resulted in 0.26g-PGA. These ratios were computed considering a seismic demand related to 10% of probability of exceedance in 50 years which is a requirement in the Peruvian seismic code. These results show an acceptable seismic performance for both buildings.

Keywords: fragility functions, university buildings, loss assessment, Montecarlo simulation, latin hypercube

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25240 Design of a Standard Weather Data Acquisition Device for the Federal University of Technology, Akure Nigeria

Authors: Isaac Kayode Ogunlade

Abstract:

Data acquisition (DAQ) is the process by which physical phenomena from the real world are transformed into an electrical signal(s) that are measured and converted into a digital format for processing, analysis, and storage by a computer. The DAQ is designed using PIC18F4550 microcontroller, communicating with Personal Computer (PC) through USB (Universal Serial Bus). The research deployed initial knowledge of data acquisition system and embedded system to develop a weather data acquisition device using LM35 sensor to measure weather parameters and the use of Artificial Intelligence(Artificial Neural Network - ANN)and statistical approach(Autoregressive Integrated Moving Average – ARIMA) to predict precipitation (rainfall). The device is placed by a standard device in the Department of Meteorology, Federal University of Technology, Akure (FUTA) to know the performance evaluation of the device. Both devices (standard and designed) were subjected to 180 days with the same atmospheric condition for data mining (temperature, relative humidity, and pressure). The acquired data is trained in MATLAB R2012b environment using ANN, and ARIMAto predict precipitation (rainfall). Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Correction Square (R2), and Mean Percentage Error (MPE) was deplored as standardize evaluation to know the performance of the models in the prediction of precipitation. The results from the working of the developed device show that the device has an efficiency of 96% and is also compatible with Personal Computer (PC) and laptops. The simulation result for acquired data shows that ANN models precipitation (rainfall) prediction for two months (May and June 2017) revealed a disparity error of 1.59%; while ARIMA is 2.63%, respectively. The device will be useful in research, practical laboratories, and industrial environments.

Keywords: data acquisition system, design device, weather development, predict precipitation and (FUTA) standard device

Procedia PDF Downloads 65
25239 Seismic Hazard Response of Bhairabi-Sairang Tunnel Due to the Effect of Faulting

Authors: Tauhidur Rahman, Subhrajit Pathak

Abstract:

In this study, structural response of Bhairabi-Sairang Tunnel due to presence of seismic faults has been thoroughly examined. There may be several active faults located in and around the project. Faults are the key seismic sources from where earthquakes are originated. The magnitude of earthquake will depend on the length of the fault. A long fault more than 200 km can produce earthquake of magnitude (Mw ) more than 8.0 and smaller length less than 10 km will produce small magnitude earthquake. Now-a-days it is very much essential to identify the distance and length of a fault from the project site. Based on this, in the present paper, a case study of the Bhairabi Sairang Tunnel of 1.73 Km length located in the North Eastern Region of India has been selected to calculate the seismic hazard from the surrounding effect of faults. A comparative study of seismic hazard at the tunnel site has been made based on the location of faults with the seismic hazard obtained from the Indian Standards code of Practice. In this paper, a practical problem of a tunnel has been analysed based on the available faults around the project site accounting the soil factor.

Keywords: seismic hazard, effect of fault, soil factor, Bhairabi Sairang tunnel

Procedia PDF Downloads 535
25238 Three Dimensional Numerical Analysis for Longitudinal Seismic Response of Tunnels under Asynchronous Earthquake

Authors: Peng Li, Er-xiang Song

Abstract:

Numerical analysis of longitudinal tunnel seismic response due to spatial variation of earthquake ground motion is an important issue that cannot be ignored in the design and safety evaluation of tunnel structures. In this paper, numerical methods for analysis of tunnel longitudinal response under asynchronous seismic wave is extensively studied, including the improvement of the 1D time-domain finite element method, three dimensional numerical simulation technique for the site asynchronous earthquake response as well as the 3-D soil-tunnel structure interaction analysis. The study outcome will be beneficial to aid further research on the nonlinear meticulous numerical analysis and seismic response mechanism of tunnel structures under asynchronous earthquake motion.

Keywords: asynchronous input, longitudinal seismic response, tunnel structure, numerical simulation, traveling wave effect

Procedia PDF Downloads 403
25237 Natural Frequency Analysis of Small-Scale Arch Structure by Shaking Table Test

Authors: Gee-Cheol Kim, Joo-Won Kang

Abstract:

Structural characteristics of spatial structure are different from that of rahmen structures and it has many factors that are unpredictable experientially. Both horizontal and vertical earthquake should be considered because of seismic behaviour characteristics of spatial structures. This experimental study is conducted about seismic response characteristics of roof structure according to the effect of columns or walls, through scale model of arch structure that has the basic dynamic characteristics of spatial structure. Though remarkable response is not occurred for horizontal direction in the region of higher frequency than the region of frequency that seismic energy is concentrated, relatively large response is occurred in vertical direction. It is proved that seismic response of arch structure with column is varied according to property of column.

Keywords: arch structure, seismic response, shaking table, spatial structure

Procedia PDF Downloads 334
25236 Comparative Study of the Distribution of Seismic Loads of Buildings with Asymmetries Plan

Authors: Ahmed Hamza Yache

Abstract:

The main purpose of this study is to estimate the distribution of shear forces in building structures with asymmetries in the plan submitted to seismic forces can cause, in this case, simultaneous deformations of translation and torsion. To this end, the distribution of shear forces is obtained by seismic forces calculated from the equivalent static method of the Algerian earthquake code RPA 99 (2003 version) and spectral modal analysis for an irregular building plan without kinks. Comparison of the results obtained by these two methods used to highlight the difference in terms of distributions of shear forces in such structures.

Keywords: structure, irregular, code, seismic, method, force, period

Procedia PDF Downloads 551
25235 Correlation between Seismic Risk Insurance Indexes and Uninhabitability Indexes of Buildings in Morocco

Authors: Nabil Mekaoui, Nacer Jabour, Abdelhamid Allaoui, Abderahim Oulidi

Abstract:

The reliability of several insurance indexes of the seismic risk is evaluated and compared for an efficient seismic risk coverage of buildings in Morocco, thus, reducing the basic risk. A large database of earthquake ground motions is established from recent seismic events in Morocco and synthetic ground motions compatible with the design spectrum in order to conduct nonlinear time history analyses on three building models representative of the building stock in Morocco. The uninhabitability index is evaluated based on the simulated damage index, then correlated with preselected insurance indexes. Interestingly, the commonly used peak ground acceleration index showed poor correlation when compared with other indexes, such as spectral accelerations at low periods. Recommendations on the choice of suitable insurance indexes are formulated for efficient seismic risk coverage in Morocco.

Keywords: catastrophe modeling, damage, earthquake, reinsurance, seismic hazard, trigger index, vulnerability

Procedia PDF Downloads 46
25234 Control of Sensors in Metering System of Fluid

Authors: A. Harrouz, O. Harrouz, A. Benatiallah

Abstract:

This paper is to review the essential definitions, roles, and characteristics of communication of metering system. We discuss measurement, data acquisition, and metrological control of a signal sensor from dynamic metering system. After that, we present control of instruments of metering system of fluid with more detailed discussions to the reference standards.

Keywords: data acquisition, dynamic metering system, reference standards, metrological control

Procedia PDF Downloads 465
25233 Analyzing Time Lag in Seismic Waves and Its Effects on Isolated Structures

Authors: Faizan Ahmad, Jenna Wong

Abstract:

Time lag between peak values of horizontal and vertical seismic waves is a well-known phenomenon. Horizontal and vertical seismic waves, secondary and primary waves in nature respectively, travel through different layers of soil and the travel time is dependent upon the medium of wave transmission. In seismic analysis, many standardized codes do not require the actual vertical acceleration to be part of the analysis procedure. Instead, a factor load addition for a particular site is used to capture strength demands in case of vertical excitation. This study reviews the effects of vertical accelerations to analyze the behavior of a linearly rubber isolated structure in different time lag situations and frequency content by application of historical and simulated ground motions using SAP2000. The response of the structure is reviewed under multiple sets of ground motions and trends based on time lag and frequency variations are drawn. The accuracy of these results is discussed and evaluated to provide reasoning for use of real vertical excitations in seismic analysis procedures, especially for isolated structures.

Keywords: seismic analysis, vertical accelerations, time lag, isolated structures

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25232 Seismic Bearing Capacity Estimation of Shallow Foundations on Dense Sand Underlain by Loose Sand Strata by Using Finite Elements Limit Analysis

Authors: Pragyan Paramita Das, Vishwas N. Khatri

Abstract:

By using the lower- and upper- bound finite elements to limit analysis in conjunction with second-order conic programming (SOCP), the effect of seismic forces on the bearing capacity of surface strip footing resting on dense sand underlain by loose sand deposit is explored. The soil is assumed to obey the Mohr-Coulomb’s yield criterion and an associated flow rule. The angle of internal friction (ϕ) of the top and the bottom layer is varied from 42° to 44° and 32° to 34° respectively. The coefficient of seismic acceleration is varied from 0 to 0.3. The variation of bearing capacity with different thickness of top layer for various seismic acceleration coefficients is generated. A comparison will be made with the available solutions from literature wherever applicable.

Keywords: bearing capacity, conic programming, finite elements, seismic forces

Procedia PDF Downloads 144
25231 Assessment of Bridge Performance with Laminated versus Spring Seismic Isolation

Authors: M. Z. Ramli, A. Adnan, Chee Wei Tan

Abstract:

To gain a better understanding of earthquake forces on reinforced concrete bridge piers with different bearing condition, a series of experiments was conducted on a realistic, 1:4 scale reinforced concrete bridge pier. The normal practices of laminated seismic isolation bearing is compared with the new design spring seismic isolation bearing where invented by Engineering Seismology and Earthquake Engineering Research (e-SEER), Universiti Teknologi Malaysia. The nonlinear behavior of piers is modeled using the fibre beam theory to verify the experimental works. The hysteresis of bridge pier with different bearing condition was illustrated under different Peak Ground Acceleration (PGAs). The average slope of the hysteresis respectively to the global stiffness was also investigated.

Keywords: bridge, laminated seismic isolation, spring seismic isolation, Peak Ground Acceleration, stiffness

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25230 Dynamic Analysis of Double Deck Tunnel

Authors: C. W. Kwak, I. J. Park, D. I. Jang

Abstract:

The importance of cost-wise effective application and construction is getting increase due to the surge of traffic volume in the metropolitan cities. Accordingly, the necessity of the tunnel has large section becomes more critical. Double deck tunnel can be one of the most appropriate solutions to the necessity. The dynamic stability of double deck tunnel is essential against seismic load since it has large section and connection between perimeter lining and interim slab. In this study, 3-dimensional dynamic numerical analysis was conducted based on the Finite Difference Method to investigate the seismic behavior of double deck tunnel. Seismic joint for dynamic stability and the mitigation of seismic impact on the lining was considered in the modeling and analysis. Consequently, the mitigation of acceleration, lining displacement and stress were verified successfully.

Keywords: double deck tunnel, interim slab, 3-dimensional dynamic numerical analysis, seismic joint

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25229 [Keynote]: No-Trust-Zone Architecture for Securing Supervisory Control and Data Acquisition

Authors: Michael Okeke, Andrew Blyth

Abstract:

Supervisory Control And Data Acquisition (SCADA) as the state of the art Industrial Control Systems (ICS) are used in many different critical infrastructures, from smart home to energy systems and from locomotives train system to planes. Security of SCADA systems is vital since many lives depend on it for daily activities and deviation from normal operation could be disastrous to the environment as well as lives. This paper describes how No-Trust-Zone (NTZ) architecture could be incorporated into SCADA Systems in order to reduce the chances of malicious intent. The architecture is made up of two distinctive parts which are; the field devices such as; sensors, PLCs pumps, and actuators. The second part of the architecture is designed following lambda architecture, which is made up of a detection algorithm based on Particle Swarm Optimization (PSO) and Hadoop framework for data processing and storage. Apache Spark will be a part of the lambda architecture for real-time analysis of packets for anomalies detection.

Keywords: industrial control system (ics, no-trust-zone (ntz), particle swarm optimisation (pso), supervisory control and data acquisition (scada), swarm intelligence (SI)

Procedia PDF Downloads 317
25228 On the Monitoring of Structures and Soils by Tromograph

Authors: Magarò Floriana, Zinno Raffaele

Abstract:

Since 2009, with the coming into force of the January 14, 2008 Ministerial Decree "New technical standards for construction", and the explanatory ministerial circular N°.617 of February 2, 2009, the question of seismic hazard and the design of seismic-resistant structures in Italy has acquired increasing importance. One of the most discussed aspects in recent Italian and international scientific literature concerns the dynamic interaction between land and structure, and the effects which dynamic coupling may have on individual buildings. In effect, from systems dynamics, it is well known that resonance can have catastrophic effects on a stimulated system, leading to a response that is not compatible with the previsions in the design phase. The method used in this study to estimate the frequency of oscillation of the structure is as follows: the analysis of HVSR (Horizontal to Vertical Spectral Ratio) relations. This allows for evaluation of very simple oscillation frequencies for land and structures. The tool used for data acquisition is an experimental digital tromograph. This is an engineered development of the experimental Languamply RE 4500 tromograph, equipped with an engineered amplification circuit and improved electronically using extremely small electronic components (size of each individual amplifier 16 x 26 mm). This tromograph is a modular system, completely "free" and "open", designed to interface Windows, Linux, OSX and Android with the outside world. It an amplifier designed to carry out microtremor measurements, yet which will also be useful for seismological and seismic measurements in general. The development of single amplifiers of small dimension allows for a very clean signal since being able to position it a few centimetres from the geophone eliminates cable “antenna” phenomena, which is a necessary characteristic in seeking to have signals which are clean at the very low voltages to be measured.

Keywords: microtremor, HVSR, tromograph, structural engineering

Procedia PDF Downloads 383
25227 Seismic Performance Evaluation of Bridge Structures Using 3D Finite Element Methods in South Korea

Authors: Woo Young Jung, Bu Seog Ju

Abstract:

This study described the seismic performance evaluation of bridge structures, located near Daegu metropolitan city in Korea. The structural design code or regulatory guidelines is focusing on the protection of brittle failure or collapse in bridges’ lifetime during an earthquake. This paper illustrated the procedure in terms of the safety evaluation of bridges using simple linear elastic 3D Finite Element (FE) model in ABAQUS platform. The design response spectra based on KBC 2009 were then developed, in order to understand the seismic behavior of bridge structures. Besides, the multiple directional earthquakes were applied and it revealed that the most dominated earthquake direction was transverse direction of the bridge. Also, the bridge structure under the compressive stress was more fragile than the tensile stress and the vertical direction of seismic ground motions was not significantly affected to the structural system.

Keywords: seismic, bridge, FEM, evaluation, numerical analysis

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25226 Competency Based Talent Acquisition: Concept, Practice, and Model, with Reference to Indian Industries

Authors: Manasi V. Shah

Abstract:

Organizations, in the competitive era, are participating in the competency act. They have discerned that, strategically researched and defined competencies when put up on the shelf, can help in achieving business goals. The research focuses on critical elements of competency-based talent acquisition process from practical vantage, with significant experience in a variety of business settings. The research is exploratory and descriptive in nature. The research conduct and outcome is the hinge on with reference to Indian Industries. It elaborates about the concept, practice and a brief model that human resource practitioner can use for effective talent acquisition process, which in turn would be in alignment with business performance. The research helps to present a prudent understanding of recruiting and selecting apt human capital, that can fit in a given job role and has action oriented competency based assessment approach for measuring the probable success of a job incumbent in a given job role.

Keywords: competency based talent acquisition, competency model, talent acquisition concept, talent acquisition practice

Procedia PDF Downloads 283
25225 Seismic Response of Structure Using a Three Degree of Freedom Shake Table

Authors: Ketan N. Bajad, Manisha V. Waghmare

Abstract:

Earthquakes are the biggest threat to the civil engineering structures as every year it cost billions of dollars and thousands of deaths, around the world. There are various experimental techniques such as pseudo-dynamic tests – nonlinear structural dynamic technique, real time pseudo dynamic test and shaking table test method that can be employed to verify the seismic performance of structures. Shake table is a device that is used for shaking structural models or building components which are mounted on it. It is a device that simulates a seismic event using existing seismic data and nearly truly reproducing earthquake inputs. This paper deals with the use of shaking table test method to check the response of structure subjected to earthquake. The various types of shake table are vertical shake table, horizontal shake table, servo hydraulic shake table and servo electric shake table. The goal of this experiment is to perform seismic analysis of a civil engineering structure with the help of 3 degree of freedom (i.e. in X Y Z direction) shake table. Three (3) DOF shaking table is a useful experimental apparatus as it imitates a real time desired acceleration vibration signal for evaluating and assessing the seismic performance of structure. This study proceeds with the proper designing and erection of 3 DOF shake table by trial and error method. The table is designed to have a capacity up to 981 Newton. Further, to study the seismic response of a steel industrial building, a proportionately scaled down model is fabricated and tested on the shake table. The accelerometer is mounted on the model, which is used for recording the data. The experimental results obtained are further validated with the results obtained from software. It is found that model can be used to determine how the structure behaves in response to an applied earthquake motion, but the model cannot be used for direct numerical conclusions (such as of stiffness, deflection, etc.) as many uncertainties involved while scaling a small-scale model. The model shows modal forms and gives the rough deflection values. The experimental results demonstrate shake table as the most effective and the best of all methods available for seismic assessment of structure.

Keywords: accelerometer, three degree of freedom shake table, seismic analysis, steel industrial shed

Procedia PDF Downloads 107
25224 The Quality Assessment of Seismic Reflection Survey Data Using Statistical Analysis: A Case Study of Fort Abbas Area, Cholistan Desert, Pakistan

Authors: U. Waqas, M. F. Ahmed, A. Mehmood, M. A. Rashid

Abstract:

In geophysical exploration surveys, the quality of acquired data holds significant importance before executing the data processing and interpretation phases. In this study, 2D seismic reflection survey data of Fort Abbas area, Cholistan Desert, Pakistan was taken as test case in order to assess its quality on statistical bases by using normalized root mean square error (NRMSE), Cronbach’s alpha test (α) and null hypothesis tests (t-test and F-test). The analysis challenged the quality of the acquired data and highlighted the significant errors in the acquired database. It is proven that the study area is plain, tectonically least affected and rich in oil and gas reserves. However, subsurface 3D modeling and contouring by using acquired database revealed high degrees of structural complexities and intense folding. The NRMSE had highest percentage of residuals between the estimated and predicted cases. The outcomes of hypothesis testing also proved the biasness and erraticness of the acquired database. Low estimated value of alpha (α) in Cronbach’s alpha test confirmed poor reliability of acquired database. A very low quality of acquired database needs excessive static correction or in some cases, reacquisition of data is also suggested which is most of the time not feasible on economic grounds. The outcomes of this study could be used to assess the quality of large databases and to further utilize as a guideline to establish database quality assessment models to make much more informed decisions in hydrocarbon exploration field.

Keywords: Data quality, Null hypothesis, Seismic lines, Seismic reflection survey

Procedia PDF Downloads 117
25223 Seismic Inversion to Improve the Reservoir Characterization: Case Study in Central Blue Nile Basin, Sudan

Authors: Safwat E. Musa, Nuha E. Mohamed, Nuha A. Bagi

Abstract:

In this study, several crossplots of the P-impedance with the lithology logs (gamma ray, neutron porosity, deep resistivity, water saturation and Vp/Vs curves) were made in three available wells, which were drilled in central part of the Blue Nile basin in depths varies from 1460 m to 1600 m. These crossplots were successful to discriminate between sand and shale when using P-Impedance values, and between the wet sand and the pay sand when using both P-impedance and Vp/Vs together. Also, some impedance sections were converted to porosity sections using linear formula to characterize the reservoir in terms of porosity. The used crossplots were created on log resolution, while the seismic resolution can identify only the reservoir, unless a 3D seismic angle stacks were available; then it would be easier to identify the pay sand with great confidence; through high resolution seismic inversion and geostatistical approach when using P-impedance and Vp/Vs volumes.

Keywords: basin, Blue Nile, inversion, seismic

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25222 Crack Propagation in Concrete Gravity Dam

Authors: Faramarz Khoshnoudian

Abstract:

A seismic stability assessment of the concrete gravity dam was performed. Initially (Phase 1), a linear response spectrum analysis was performed to verify the potential for crack formation. The result shows the possibility of developing cracks in the upstream face of the dam close to the lowest gallery, which were sufficiently long that the dam would not be stable following the earthquake. The results show the dam has potentially inadequate seismic and post-earthquake resistance and recommended an update of the stability analysis.

Keywords: crack propgation, concrete gravity dam, seismic, assesment

Procedia PDF Downloads 41
25221 Seismic Vulnerability Analysis of Arch Dam Based on Response Surface Method

Authors: Serges Mendomo Meye, Li Guowei, Shen Zhenzhong

Abstract:

Earthquake is one of the main loads threatening dam safety. Once the dam is damaged, it will bring huge losses of life and property to the country and people. Therefore, it is very important to research the seismic safety of the dam. Due to the complex foundation conditions, high fortification intensity, and high scientific and technological content, it is necessary to adopt reasonable methods to evaluate the seismic safety performance of concrete arch dams built and under construction in strong earthquake areas. Structural seismic vulnerability analysis can predict the probability of structural failure at all levels under different intensity earthquakes, which can provide a scientific basis for reasonable seismic safety evaluation and decision-making. In this paper, the response surface method (RSM) is applied to the seismic vulnerability analysis of arch dams, which improves the efficiency of vulnerability analysis. Based on the central composite test design method, the material-seismic intensity samples are established. The response surface model (RSM) with arch crown displacement as performance index is obtained by finite element (FE) calculation of the samples, and then the accuracy of the response surface model (RSM) is verified. To obtain the seismic vulnerability curves, the seismic intensity measure ??(?1) is chosen to be 0.1~1.2g, with an interval of 0.1g and a total of 12 intensity levels. For each seismic intensity level, the arch crown displacement corresponding to 100 sets of different material samples can be calculated by algebraic operation of the response surface model (RSM), which avoids 1200 times of nonlinear dynamic calculation of arch dam; thus, the efficiency of vulnerability analysis is improved greatly.

Keywords: high concrete arch dam, performance index, response surface method, seismic vulnerability analysis, vector-valued intensity measure

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25220 Collapse Capacity Assessment of Inelastic Structures under Seismic Sequences

Authors: Shahrzad Mohammadi, Ghasem Boshrouei Sharq

Abstract:

All seismic design codes are based on the determination of the design earthquake without taking into account the effects of aftershocks in the design practice. In regions with a high level of seismicity, the occurrence of several aftershocks of various magnitudes and different time lags is very likely. This research aims to estimate the collapse capacity of a 10-story steel bundled tube moment frame subjected to as-recorded seismic sequences. The studied structure is designed according to the seismic regulations of the fourth revision of the Iranian code of practice for the seismic-resistant design of buildings (Code No.2800). A series of incremental dynamic analyses (IDA) is performed up to the collapse level of the intact structure. Then, in order to demonstrate the effects of aftershock events on the collapse vulnerability of the building, aftershock IDA analyzes are carried out. To gain deeper insight, collapse fragility curves are developed and compared for both series. Also, a study on the influence of various ground motion characteristics on collapse capacity is carried out. The results highlight the importance of considering the decisive effects of aftershocks in seismic codes due to their contribution to the occurrence of collapse.

Keywords: IDA, aftershock, bundled tube frame, fragility assessment, GM characteristics, as-recorded seismic sequences

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25219 Delineation of the Geoelectric and Geovelocity Parameters in the Basement Complex of Northwestern Nigeria

Authors: M. D. Dogara, G. C. Afuwai, O. O. Esther, A. M. Dawai

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The geology of Northern Nigeria is under intense investigation particularly that of the northwest believed to be of the basement complex. The variability of the lithology is consistently inconsistent. Hence, the need for a close range study, it is, in view of the above that, two geophysical techniques, the vertical electrical sounding employing the Schlumberger array and seismic refraction methods, were used to delineate the geoelectric and geovelocity parameters of the basement complex of northwestern Nigeria. A total area of 400,000 m² was covered with sixty geoelectric stations established and sixty sets of seismic refraction data collected using the forward and reverse method. From the interpretation of the resistivity data, it is suggestive that the area is underlain by not more than five geoelectric layers of varying thicknesses and resistivities when a maximum half electrode spread of 100m was used. The result of the interpreted seismic data revealed two geovelocity layers, with velocities ranging between 478m/s to 1666m/s for the first layer and 1166m/s to 7141m/s for the second layer. The results of the two techniques, suggests that the area of study has an undulating bedrock topography with geoeletric and geovelocity layers composed of weathered rock materials.

Keywords: basement complex, delineation, geoelectric, geovelocity, Nigeria

Procedia PDF Downloads 126
25218 Design of Labview Based DAQ System

Authors: Omar A. A. Shaebi, Matouk M. Elamari, Salaheddin Allid

Abstract:

The Information Computing System of Monitoring (ICSM) for the Research Reactor of Tajoura Nuclear Research Centre (TNRC) stopped working since early 1991. According to the regulations, the computer is necessary to operate the reactor up to its maximum power (10 MW). The fund is secured via IAEA to develop a modern computer based data acquisition system to replace the old computer. This paper presents the development of the Labview based data acquisition system to allow automated measurements using National Instruments Hardware and its labview software. The developed system consists of SCXI 1001 chassis, the chassis house four SCXI 1100 modules each can maintain 32 variables. The chassis is interfaced with the PC using NI PCI-6023 DAQ Card. Labview, developed by National Instruments, is used to run and operate the DAQ System. Labview is graphical programming environment suited for high level design. It allows integrating different signal processing components or subsystems within a graphical framework. The results showed system capabilities in monitoring variables, acquiring and saving data. Plus the capability of the labview to control the DAQ.

Keywords: data acquisition, labview, signal conditioning, national instruments

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25217 Qualitative Review of Seismic Response of Vertically Irregular Building Frames

Authors: Abdelhammid Chibane

Abstract:

This study summarizes state-of-the-art knowledge in the seismic response of vertically irregular building frames. Criteria defining vertical irregularity as per the current building codes have been discussed. A review of studies on the seismic behaviour of vertically irregular structures along with their findings has been presented. It is observed that building codes provide criteria to classify the vertically irregular structures and suggest dynamic analysis to arrive at design lateral forces. Most of the studies agree on the increase in drift demand in the tower portion of set-back structures and on the increase in seismic demand for buildings with discontinuous distributions in mass, stiffness, and strength. The largest seismic demand is found for the combined-stiffness-and-strength irregularity.

Keywords: mass irregularity, set-back structure, stiffness irregularity, strength irregularity, vertical irregularity

Procedia PDF Downloads 239
25216 Amplitude Versus Offset (AVO) Modeling as a Tool for Seismic Reservoir Characterization of the Semliki Basin

Authors: Hillary Mwongyera

Abstract:

The Semliki basin has become a frontier for petroleum exploration in recent years. Exploration efforts have resulted into extensive seismic data acquisition and drilling of three wells namely; Turaco 1, Turaco 2 and Turaco 3. A petrophysical analysis of the Turaco 1 well was carried out to identify two reservoir zones on which AVO modeling was performed. A combination of seismic modeling and rock physics modeling was applied during reservoir characterization and monitoring to determine variations of seismic responses with amplitude characteristics. AVO intercept gradient analysis applied on AVO synthetic CDP gathers classified AVO anomalies associated with both reservoir zones as Class 1 AVO anomalies. Fluid replacement modeling was carried out on both reservoir zones using homogeneous mixing and patchy saturation patterns to determine effects of fluid substitution on rock property interactions. For both homogeneous mixing and saturation patterns, density (ρ) showed an increasing trend with increasing brine substitution while Shear wave velocity (Vs) decreased with increasing brine substitution. A study of compressional wave velocity (Vp) with increasing brine substitution for both homogeneous mixing and patchy saturation gave quite interesting results. During patchy saturation, Vp increased with increasing brine substitution. During homogeneous mixing however, Vp showed a slightly decreasing trend with increasing brine substitution but increased tremendously towards and at full brine saturation. A sensitivity analysis carried out showed that density was a very sensitive rock property responding to brine saturation except at full brine saturation during homogeneous mixing where Vp showed greater sensitivity with brine saturation. Rock physics modeling was performed to predict diagnostics of reservoir quality using an inverse deterministic approach which showed low shale content and a high degree of shale stiffness within reservoir zones.

Keywords: Amplitude Versus Offset (AVO), fluid replacement modelling, reservoir characterization, AVO attributes, rock physics modelling, reservoir monitoring

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25215 Study of the Influence of Eccentricity Due to Configuration and Materials on Seismic Response of a Typical Building

Authors: A. Latif Karimi, M. K. Shrimali

Abstract:

Seismic design is a critical stage in the process of design and construction of a building. It includes strategies for designing earthquake-resistant buildings to ensure health, safety, and security of the building occupants and assets. Hence, it becomes very important to understand the behavior of structural members precisely, for construction of buildings that can yield a better response to seismic forces. This paper investigates the behavior of a typical structure when subjected to ground motion. The corresponding mode shapes and modal frequencies are studied to interpret the response of an actual structure using different fabricated models and 3D visual models. In this study, three different structural configurations are subjected to horizontal ground motion, and the effect of “stiffness eccentricity” and placement of infill walls are checked to determine how each parameter contributes in a building’s response to dynamic forces. The deformation data from lab experiments and the analysis on SAP2000 software are reviewed to obtain the results. This study revealed that seismic response in a building can be improved by introducing higher deformation capacity in the building. Also, proper design of infill walls and maintaining a symmetrical configuration in a building are the key factors in building stability during the earthquake.

Keywords: eccentricity, seismic response, mode shape, building configuration, building dynamics

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25214 Sequence Stratigraphy and Petrophysical Analysis of Sawan Gas Field, Central Indus Basin, Pakistan

Authors: Saeed Ur Rehman Chaudhry

Abstract:

The objectives of the study are to reconstruct sequence stratigraphic framework and petrophysical analysis of the reservoir marked by using sequence stratigraphy of Sawan Gas Field. The study area lies in Central Indus Basin, District Khairpur, Sindh province, Pakistan. The study area lies tectonically in an extensional regime. Lower Goru Formation and Sembar Formation act as a reservoir and source respectively. To achieve objectives, data set of seismic lines, consisting of seismic lines PSM96-114, PSM96-115, PSM96-133, PSM98-201, PSM98-202 and well logs of Sawan-01, Sawan-02 and Gajwaro-01 has been used. First of all interpretation of seismic lines has been carried out. Interpretation of seismic lines shows extensional regime in the area and cut entire Cretaceous section. Total of seven reflectors has been marked on each seismic line. Lower Goru Formation is thinning towards west. Seismic lines also show eastward tilt of stratigraphy due to uplift at the western side. Sequence stratigraphic reconstruction has been done by integrating seismic and wireline log data. Total of seven sequence boundaries has been interpreted between the top of Chiltan Limestone to Top of Lower Goru Formation. It has been observed on seismic lines that Sembar Formation initially generated shelf margin profile and then ramp margin on which Lower Goru deposition took place. Shelf edge deltas and slope fans have been observed on seismic lines, and signatures of slope fans are also observed on wireline logs as well. Total of six sequences has been interpreted. Stratigraphic and sequence stratigraphic correlation has been carried out by using Sawan 01, Sawan 02 and Gajwaro 01 and a Low Stand Systems tract (LST) within Lower Goru C sands has been marked as a zone of interest. The petrophysical interpretation includes shale volume, effective porosity, permeability, saturation of water and hydrocarbon. On the basis of good effective porosity and hydrocarbon saturation petrophysical analysis confirms that the LST in Sawan-01 and Sawan-02 has good hydrocarbon potential.

Keywords: petrophysical analysis, reservoir potential, Sawan Gas Field, sequence stratigraphy

Procedia PDF Downloads 241
25213 Seismic Response of Moment Resisting Steel Frame with Hysteresis Envelope Model of Joints

Authors: Krolo Paulina

Abstract:

The seismic response of moment-resisting steel frames depends on the behavior of the joints, especially when they are considered as ductile zones. The aim of this research is to provide a realistic assessment of the moment-resisting steel frame behavior under seismic loading using nonlinear static pushover analysis (N2 method). The hysteresis behavior of the joints in the frame model was described using a new hysteresis envelope model. The obtained seismic response was compared with the results of the seismic analysis obtained for the same steel frame that takes into account the monotonic model of the joints.

Keywords: beam-to-column joints, hysteresis envelope model, moment-resisting frame, nonlinear static pushover analysis, N2 method

Procedia PDF Downloads 243