DOCSLIB.ORG

Earthquake Duration and Damping Effects on Input Energy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Earthquake Duration and Damping Effects on Input Energy Earthquake Duration and Damping Effects on Input Energy G. Ghodrati Amiri1, G. Abdollahzadeh Darzi2 and M. Khanzadi3 1Associate Professor, Email:[email protected] 2Ph.D. Candidate 3Assistant Professor Center of Excellence for Fundamental Studies in Structural Engineering, College of Civil Engineering, Iran University of Science & Technology, Tehran, Iran Abstract: According to performance-based seismic design method by using energy concept, in this paper it is tried to investigate the duration and damping effects on elastic input energy due to strong ground motions. Based on reliable Iranian earthquake records in four types of soils, structures were analyzed and equivalent velocity spectra were computed by using input energy. These spectra were normalized with respect to PGA and were drawn for different durations, damping ratios and soil types and then effects of these parameters were investigated on these spectra. Finally it was concluded that in average for different soil types when the duration of ground motions increases, the input energy to structure increases too. Also it was observed that input energy to structures in soft soils is larger than that for stiff soils and with increasing the stiffness of the earthquake record soil type, the input energy decreases. But damping effect on input energy is not very considerable and input energy to structure with damping ratio about 5% has the minimum value. Keywords: PGA; duration of strong ground motion; damping ratio; input energy spectrum. 1. Introduction Researches considered that among various types of energy the input energy, EI which is Design of structures with performance-based a very stable parameter of structural design especially based on energy is one of response, is suitable for energy-based design. Downloaded from ijce.iust.ac.ir at 22:42 IRST on Saturday October 2nd 2021 the methods noticed by researches in the Input energy is a measure of energy that recent years [1-8]. Unlike present methods earthquake inputs to structures during the which are based on peak accelerations that ground motion. Based on definition, two ignore duration and hysteretic behavior types of input energy exist [9], relative input B effects on structural design, design based on energy, EI and absolute input energy, EI . The B energy not only considers the effects of these difference between EI and EI is the effect of parameters, but also it can describe treatment the rigid body translation of structure. If EI B of structures during an earthquake, better and EI are evaluated at the end of ground than present methods. motion duration, it can be considered that they differ in the very short and very long In this method formed on the basis of energy period ranges only. concepts and energy balance equation, energy criterion expresses that the structure In a structure if its supply energy was larger collapses when the amount of capacity than its imposed energy, all the energy energy lower than the demand energy to exerted to the structure during ground motion dissipate through inelastic deformations is is dissipated through damping and hysteretic exerted. cyclic behavior of structure at the end of 14 International Journal of Civil Engineerng. Vol. 5, No. 1, March 2007 ground motion. This inelastic cyclic behavior [12], Akiyama [13] and Nakashima et al. [14] causes partial damages in structures and with observed that damping does not have a accumulation of these partial damages, significant influence on the earthquake input structures collapse. Therefore the input energy. energy demand can be assumed as a reliable Results of the study by Bruneau and Wang tool to predict the seismic hazard and seismic [15] indicated that damping ratios smaller design. than 5% have a minor influence on the input energy. Thus evaluation of influence of structural Rahnama and Manuel [16] computed the parameters, characteristics of earthquake input energy for ductility ratios of 2 and 6 records and soil conditions on input energy with 5% damping for six sets of 19 are important. accelerations each, actual records and simulated records with the same duration 5, In this paper, the effects of ground motion 10, 15 and 20 s. They considered that when duration, structural damping and soil type on duration increases, the input energy input energy were studied, by use of 110 increases. Iranian earthquake records. Because these Khashaee et al. [17] computed the relative records are collected from different input energy for 10 accelerations with short earthquakes with various PGA's, in order that duration (shorter than 8 s) and 10 with long the effects of earthquake PGA in result of duration (longer than 18 s) of strong ground each analysis are vanished, and also their motions. They observed that as the duration responses can be added together, the amount of strong ground motions increases, the input of input energy was divided by its PGA and energy also increases. They computed the the spectrum curve of input energy was relative input energy for structures with drawn. This procedure is also performed in damping ratios 0, 2, 5, 10, 20 and 40% for the previous researches on this topic such as three accelerations with short duration and Benavent–Climent's work [2]. three with long duration of strong ground motion. They observed that for damping Downloaded from ijce.iust.ac.ir at 22:42 IRST on Saturday October 2nd 2021 ratios smaller than 5%, damping has little 2. Literature Review influence on the input energy while for damping ratios greater than 5%, damping has Previously many of researches investigated a significant influence on the input energy the duration of ground motion, damping of spectra, particularly for very long natural structure and soil condition influences on periods as the damping increases, the input input energy and obtained different energy increases. conclusions. Zahrah and Hall [11] computed the input 3. Theoretical Background energy for eight earthquake records and they considered that ductility, damping and past- When a viscous damped single mass elastic to-pre yield stiffness ratios have small effects oscillatory system, SDOF, vibrates subject to on the input and hysteretic energies for a a unidirectional horizontal ground motion, its structure with bilinear behavior. equilibrium equation can be expressed as follows [9]. && & Based on many analyses, McKevitt et al. Myt Cy Ky 0 (1) International Journal of Civil Engineerng. Vol. 5, No. 1, March 2007 15 t0 t0 1 2 2 1 2 Where M, C, K and y are mass, viscous & & && & Myt ∫ Cy dt Ky M ∫ yt xg dt damping coefficient, spring constant and 2 0 2 0 c c relative displacement of the mass, Ek Ed Es EI (6) respectively. yt = y+xg is absolute. .. (or total) displacement of the mass. y and yt are first Where: derivation of y and the second derivation of y 1 t0 . t Ec My& 2 , E Cy& 2 dt with respect to time respectively. x and x k t d ∫ g g 2 0 are earthquake ground displacement and ground acceleration, respectively. t0 1 2 c && & Es Ky , EI M ∫ yt xg dt && &&&& 2 0 By letting yt y xg Equation (1) can be B re-written as follows: Here Ek, Ed and Es are absolute kinetic energy, the energy dissipated by damping && & && My Cy Ky Mxg (2) mechanism and the energy absorbed by spring, respectively, and EB is defined as the .. I Where, y is the second derivation of y with absolute input energy. This definition is respect to time. physically meaningful in where the term && Myt represents the inertia force applied to the Therefore the structural system in a moving structure. This force, from Equation (1), is base system can be treated conveniently as equal to restoring force plus damping force, an equivalent system with a fixed base which is the same as the total force applied to B subjected to an effective horizontal dynamic the structure foundation. Therefore E I − . force of magnitude M xg Depending upon represents the work done by the total base whether Equation (1) or (2) is used to derive shear at the foundation through the the energy equation, different definitions of foundation displacement. input energy may result. Method 2 – Derivation of relative energy equation Downloaded from ijce.iust.ac.ir at 22:42 IRST on Saturday October 2nd 2021 Method 1- Derivation of absolute energy If both sides. of Equation (2) are multiplied equation by dy(=y dt) and then integrated over the If both sidesH of Equation (1) are multiplied entire duration of an earthquake,t, Equation by dy(= ydt) and then integrated over the (2) reduces to the following energy balance entire duration of an earthquake, t0, Equation equation: (1) reduces to the following energy balance t0 t0 t0 t0 && & & & & && & equation: ∫ My(ydt) ∫Cy(ydt) ∫ K y(ydt) ∫ Mxg (ydt) 0 0 0 0 t0 t0 t && & & & & ∫ Myt (ydt) ∫∫Cy(ydt) Ky(ydt) 0 (3) (7) 0 00 t0 t0 t0 t0 H H − H &&& & 2 & && & Replacing y by y t xg in the first term of ∫ M yydt ∫Cy dt ∫ K yydt ∫ Mxg ydt (8) Equation (3), then 0 0 0 0 ttt 000 t0 t0 M&y& (y& x& )dt Cy& 2 dt Kyy&dt 0 (4) 1 & 2 & 2 1 2 && & (9) ∫∫∫t t g My ∫Cy dt Ky M ∫ xg ydt 000 2 0 2 0 tttt0000 2 && & & & && & ∫∫∫∫My t yt dt Cy dt Kyydt Myt xg dt 0000 (5) Ek Ed Es EI (10) 16 International Journal of Civil Engineerng. Vol. 5, No. 1, March 2007 − Where: y= xg and yt = y+xg = 0, 1 t0 E My& 2 , E Cy& 2 dt . k d ∫ therefore EB =0 and E = 0.5 M x2 2 0 I I g t0 i.e. the difference between the input energies 1 2 && & Es Ky , EI M ∫ xg ydt and for a structure.
Load more

Recommended publications
  • Preliminary Seismic Microzoning of the Town of Rudbar Part
    Guidelines for Earthquake Disaster Management, Volume I, Part 9.1 Part 9.1 Preliminary seismic microzoning of the town of Rudbar Jakim T. Petrovski, Chief Technical Advisor Professor, Institute of Earthquake Engineering and Engineering Seismology, University "St. Cyril and Methodius", Skopje, Macedonia Zoran V. Milutinovic, International Consultant Professor, Institute of Earthquake Engineering and Engineering Seismology, University "St. Cyril and Methodius", Skopje, Macedonia Behrouz Gatmiri, National Consultant Assoc. Professor, University of Tehran, Tehran Senior Researcher and Lecturer Ecole Nationale des Ponts et Chausé es, Paris, France Tehran - Skopje, September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
    [Show full text]
  • The Study on Integrated Water Resources Management for Sefidrud River Basin in the Islamic Republic of Iran
    WATER RESOURCES MANAGEMENT COMPANY THE MINISTRY OF ENERGY THE ISLAMIC REPUBLIC OF IRAN THE STUDY ON INTEGRATED WATER RESOURCES MANAGEMENT FOR SEFIDRUD RIVER BASIN IN THE ISLAMIC REPUBLIC OF IRAN Final Report Volume I Main Report November 2010 JAPAN INTERNATIONAL COOPERATION AGENCY GED JR 10-121 WATER RESOURCES MANAGEMENT COMPANY THE MINISTRY OF ENERGY THE ISLAMIC REPUBLIC OF IRAN THE STUDY ON INTEGRATED WATER RESOURCES MANAGEMENT FOR SEFIDRUD RIVER BASIN IN THE ISLAMIC REPUBLIC OF IRAN Final Report Volume I Main Report November 2010 JAPAN INTERNATIONAL COOPERATION AGENCY THE STUDY ON INTEGRATED WATER RESOURCES MANAGEMENT FOR SEFIDRUD RIVER BASIN IN THE ISLAMIC REPUBLIC OF IRAN COMPOSITION OF FINAL REPORT Volume I : Main Report Volume II : Summary Volume III : Supporting Report Currency Exchange Rates used in this Report: USD 1.00 = RIAL 9,553.59 = JPY 105.10 JPY 1.00 = RIAL 90.91 EURO 1.00 = RIAL 14,890.33 (As of 31 May 2008) The Study on Integrated Water Resources Management Executive Summary for Sefidrud River Basin in the Islamic Republic of Iran WATER RESOURCES POTENTIAL AND ITS DEVELOPMENT PLAN IN THE SEFIDRUD RIVER BASIN 1 ISSUES OF WATER RESOURCES MANAGEMENT IN THE BASIN The Islamic Republic of Iran (hereinafter "Iran") is characterized by its extremely unequally distributed water resources: Annual mean precipitation is 250 mm while available per capita water resources is 1,900 m3/year, which is about a quarter of the world mean value. On the other hand, the water demands have been increasing due to a rapid growth of industries, agriculture and the population. About 55 % of water supply depends on the groundwater located deeper than 100 meters in some cases.
    [Show full text]
  • The Morphology, Setting and Processes of Rudbar and Fatalak Landslides Triggered by the 1990 Manjil-Rudbar Earthquake in Iran
    Master Thesis in Geosciences The Morphology, Setting and Processes of Rudbar and Fatalak Landslides Triggered by the 1990 Manjil-Rudbar Earthquake in Iran Hassan Shahrivar- Hirad Nadim The Morphology, Setting and Processes of Rudbar and Fatalak Landslides Triggered by the 1990 Manjil-Rudbar Earthquake in Iran Hassan Shahrivar- Hirad Nadim Master Thesis in Geosciences Discipline: Environmental Geology and Geohazards Department of Geosciences Faculty of Mathematics and Natural Sciences UNIVERSITY OF OSLO [June 2005] © Hassan Shahrivar, Hirad Nadim, 2005 Tutor(s): Dr. Farrokh Nadim (UIO and Norwegian Geotechnical Institute) and Dr. Anders Elverhøi (UIO) This work is published digitally through DUO – Digitale Utgivelser ved UiO http://www.duo.uio.no It is also catalogued in BIBSYS ( http://www.bibsys.no/english ) All rights reserved. No part of this publication may be reproduced or transmitted, in any form or by any means, without permission . Cover: The Rudbar Debris Flow, Northern Iran, Anders Elverhøi. 4 Acknowledgment The authors thank the Department of Geosciences, University of Oslo for their valuable courses during the master study of authors. The International Centre for Geohazards (ICG) of the Norwegian Geotechnical Institute is gratefully thanked for technical and financial supports. The Geological Survey of Iran (GSI) facilitated the data sampling and field investigation. We thank all of our colleagues there for their great help. The International Academic Affairs is appreciated for their financial support during the study. Special thanks go to Professor Farrokh Nadim of ICG and Professor Anders Elverhøi of the Department of Geosciences, University of Oslo (UiO) for their supervision. Many friends and classmates helped a lot to facilitate the study here we thank all of them.
    [Show full text]
  • Evolution of the Sefidrud Delta (South West Caspian Sea) During the Last Millennium
    Evolution of the Sefidrud Delta (South West Caspian Sea) during the last millennium A thesis submitted for the degree of Doctor of Philosophy By Safiyeh Haghani Environmental Science Brunel University London July 2015 Declaration This thesis is the result of the author’s own work. Data or information from other authors contained herein, are acknowledge at the appropriate point in the text. Abstract The Sefidrud has developed a large delta in the south west of the Caspian Sea. Its delta is characterized by rapid sedimentation rate (20 mm/yr) in the delta plain and low sedimentation rate (1.67 mm/yr) in a very steep delta front. Sefidrud Delta evolution depends upon sediment supply by river and longshore current under rapid Caspian Sea Level (CSL) fluctuation and tectonic setting at the point of entry to the basin. The tectonic setting caused a very steep slope in the delta front. Sediment supply is variable and affected by river avulsion and dam construction. The CSL has undergone significant changes during the last millennium. Therefore, the Sefidrud Delta evolution during the last millennium is explained based on CSL fluctuations. This fluctuation has major impacts not only on coastal lagoons, but also more inland in wetlands when the CSL rose up to at least -21.44 m (i.e. >6 m above the present water level) during the early Little Ice Age. Although previous studies in the southern coast of the Caspian Sea have detected a high- stand during the Little Ice Age period, this study presents the first evidence that this high- stand reached so far inland and at such a high altitude.
    [Show full text]
  • Sefidrud Harder, Adjust with Adding More Flour Or Across the Width of the Gilan Province to the Caspian Sea; Oil
    No.1860,Monday,13 May,2019 The 27th International Quran Exhibition will be opened at Tehran’s Imam Khomeini . Mosalla on Saturday evening during a special ceremony attended by Minister of Cul- www TOURISMpaper com ture and Islamic Guidance Abbas Salehi and a number of cultural figures.The world’s biggest Quranic event, the expo has numerous sections and each one is dedicated to a certain activity related to the Quran.The international art section of the event is where artists from around the world showcase valuable artworks inspired by the holy book of Islam.Showcasing more than one hundred works from professional Iranian Tehran to hold contemporary artists, a new gallery dedicated to the works of renowned Iranian artists welcomes visitors in the 27th international Quran exhibition. The paintings, photo- 27th intl. Quran graphs and sculptures on display carry mystical and Quranic messages. exhibition 4 Gilan, a Paradise cooking Halva in Northern Iran ■ 3 Cups Flour ■ 1/4 Tsp Zafran (Saffran) he northern province of Gilan, which encom- ■ 1 Tbsp Cocoa Powder passes the western end of the Alborz Moun- ■ 1/2 Tsp Ginger Powder T tains and lies along the Caspian Sea, is privi- ■ 3/4 Cup Sugar leged by unique nature and rich historical background. ■ 1 Cup Oil Filled with and dense rainforests and over 40 rivers, ■ 1/2 Tsp Cardamom the green province attracts thousands of tourists every ■ 2 Tbsp Rose Water year. By: Behnam Yousefi ■ 1 oz (28g) Butter Preparations: 1- Soak the Zafran (saffron) in boiling water for 30 Minutes. Abidar Park Recreational Complex in Iran’s Kurdistan he Abidar Park Recreational meters and The Small Abidar is about beautiful landscape from above the Complex, also known as 2350 meters above sea level.
    [Show full text]
  • Sefidrud, the Longest River in North of Iran
    July 5, 2021 Museum restoration E mergency restoration of Pirahmad Zahrnush Museum in Abhar in the northern province of Zanjan was completed, said the city’s Cultural Heritage, Tourism 5 and Handicrafts Department, CHTN reported. Iranica SSefidrud,efidrud, tthehe llongestongest rriveriver iinn nnorthorth ooff IIranran persiantourismguide.com riginating from Chehel Chesh- their direction to the southeast. such as Abroud, Siah Rudbar, Tuysen, it is not surprising that along with the meh Mountain in the moun- Then Zanjan River, which origi- and Sheli to Sefidrud and after pass- beautiful nature of Gilan, this region Otains of Kurdestan, the Se- nates from Soltaniyeh, and other small ing the farms along the river to the also has many historical and cultural fidrud River easily opened its way tributaries flowing from Tarom Moun- northeast and Tajan region. Finally, the attractions. The ancient Marlik Hill, among the northern mountains of tains, join it and finally reaches Manjil main branch of the river flows into the the Lushan Brick Bridge, the nomad- Iran to the Caspian Sea. This beauti- Strait. Caspian Sea through hundreds of ag- ic life of the people in a part of the ful river, known in ancient history as Up to this point, the river is called ricultural canals and waterways near Amarloo area, the summer village of Amard (Greek: Amardus), has many Qezel Uzan (or Red River). In this Bandar Anzali. Bareh Sar, etc. are some of these tour- other names. But these days everyone place, another branch called Shahrud ist attractions. knows it by the name Sepid or Sefid joins it.
    [Show full text]
  • The Rudbr Mw 7.3 Earthquake of 1990 June 20
    Geophysical Journal International Geophys. J. Int. (2010) 182, 1577–1602 doi: 10.1111/j.1365-246X.2010.04705.x The Rudbar¯ Mw 7.3 earthquake of 1990 June 20; seismotectonics, coseismic and geomorphic displacements, and historic earthquakes of the western ‘High-Alborz’, Iran Manuel Berberian1 and Richard Walker2 11224 Fox Hollow Drive, Toms River, NJ 08755-2179, USA. E-mail: [email protected] 2Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK. E-mail: [email protected] Accepted 2010 June 17. Received 2010 June 17; in original form 2008 December 21 Downloaded from https://academic.oup.com/gji/article/182/3/1577/600044 by guest on 01 October 2021 SUMMARY The Rudbar¯ earthquake of 1990 June 20, the first large-magnitude earthquake with 80 km left-lateral strike-slip motion in the western ‘High-Alborz’ fold-thrust mountain belt, was one of the largest, and most destructive, earthquakes to have occurred in Iran during the instrumental period. We bring together new and existing data on macroseismic effects, the rupture characteristics of the mainshock, field data, and the distribution of aftershocks, to provide a better description of the earthquake source, its surface ruptures, and active tectonic characteristics of the western ‘High-Alborz’. The Rudbar¯ earthquake is one of three large magnitude events to have occurred in this part of the Alborz during recorded history. The damage distribution of the 1485 August 15 Upper Polrud earthquake suggests the east–west Kelishom left-lateral fault, which is situated east of the Rudbar¯ earthquake fault, as a possible source.
    [Show full text]
  • Estimating Flood Potential Emphasizing on Geomorphologic Characteristics in Tarikn Basin Using the SCS Method
    Available online a t www.pelagiaresearchlibrary.com Pelagia Research Library European Journal of Experimental Biology, 2012, 2 (5):1928-1935 ISSN: 2248 –9215 CODEN (USA): EJEBAU Estimating Flood Potential Emphasizing on Geomorphologic Characteristics in Tarikn Basin Using the SCS Method 1Ardavan Behzad, 2Mohammad Reza Sarvati, 3Ebrahim Moghimi 1Department of Physical Geography, Science and Research Branch, Islamic Azad University, Tehran, Iran 2Dep. of Geography, University of Shaheed Beheshti, Iran 3Dep. of Geography, University of Tehran, Iran _____________________________________________________________________________________________ ABSTRACT Flood is a phenomenon which causes large damages annually and it has been always considered by hydrologists. Factors such as physiography, geomorphology and human factors that can cause acceleration of this phenomenon in the basins; since the exploitation of water resources projects, flood control, dam construction, operation, and most areas of Watershed Hydrology, flood flow is important. The degree of accuracy and safety studies, facility design and construction of water, depends heavily on the research method. In the present study the potential of Tarik flood basin has been studied using the SCS. Hydrograph of the basin according to rainfall amounts of 24- hour, time of concentration, curve number, rainfall excess, time to peak and peak, respectively, then the flood hydrograph for the basin in the Tarik periods of 2, 5, 10, 25, 50 and 100 years were calculated. The results showed that in terms of form , Tarik basin flood rise can not be because the basin is considered to be stretched, but this basin, the basin is a narrow, short channel length and minor runoffs of rainfall in a short time to reach the main drainage fill and drainage work.
    [Show full text]
  • The Rudbr Mw 7.3 Earthquake of 1990 June 20
    Geophysical Journal International Geophys. J. Int. (2010) doi: 10.1111/j.1365-246X.2010.04705.x The Rudbar¯ Mw 7.3 earthquake of 1990 June 20; seismotectonics, coseismic and geomorphic displacements, and historic earthquakes of the western ‘High-Alborz’, Iran Manuel Berberian1 and Richard Walker2 11224 Fox Hollow Drive, Toms River, NJ 08755-2179, USA. E-mail: [email protected] 2Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK. E-mail: [email protected] Accepted 2010 June 17. Received 2010 June 17; in original form 2008 December 21 SUMMARY The Rudbar¯ earthquake of 1990 June 20, the first large-magnitude earthquake with 80 km left-lateral strike-slip motion in the western ‘High-Alborz’ fold-thrust mountain belt, was one of the largest, and most destructive, earthquakes to have occurred in Iran during the instrumental period. We bring together new and existing data on macroseismic effects, the rupture characteristics of the mainshock, field data, and the distribution of aftershocks, to provide a better description of the earthquake source, its surface ruptures, and active tectonic characteristics of the western ‘High-Alborz’. The Rudbar¯ earthquake is one of three large magnitude events to have occurred in this part of the Alborz during recorded history. The damage distribution of the 1485 August 15 Upper Polrud earthquake suggests the east–west Kelishom left-lateral fault, which is situated east of the Rudbar¯ earthquake fault, as a possible source. The 1608 April 20 Alamutrud earthquake may have occurred on the Alamutrud fault farther east. Analysis of satellite imagery suggests that total left-lateral displacements on the Rudbar¯ fault are a maximum of 1 km.
    [Show full text]
  • Determination of Design Acceleration Spectra for Different Site Conditions, Magnitudes, Safety Levels and Damping Ratios in Iran
    Determination of Design Acceleration Spectra for Different Site Conditions, Magnitudes, Safety Levels and Damping Ratios in Iran G. Ghodrati Amiri1, F. Manouchehri Dana2, S. Sedighi2 Received 9 April 2006; revised 19 June 2007; accepted 22 April 2008 Abstract: By application of design spectra in seismic analyses, determination of design spectra for different site conditions, magnitudes, safety levels and damping ratios will improve the accuracy of seismic analysis results. The result of this research provides different design acceleration spectra based on Iran earthquakes database for different conditions. For this purpose first a set of 146 records was selected according to causative earthquake specifications, device error modification and site conditions. Then the design acceleration spectra are determined for 4 different site conditions presented in Iranian code of practice for seismic resistant design of buildings (Standard No. 2800), different magnitudes (MsO5.5 & Ms>5.5), different damping ratios (0, 2, 5, 10, 20 percent) and also various safety levels (50% & 84%). Also this research compares the determined design spectra with those in Standard No. 2800. Keywords: Design Acceleration Spectrum; Site Conditions; Magnitude; Safety Level; Damping. 1. Introduction conditions. The design spectrum could be derived from response spectrum of records by Design spectra are used in seismic analysis the mean of mathematical methods. Response methods such as equivalent static lateral force spectrum is the maximum response of a single analysis, dynamic spectral analysis and time degree of freedom system to a specific history dynamic analysis. Design spectra are excitement as a function of natural frequency and directly used in the first and second methods and damping of the system.
    [Show full text]
  • Investigation of Influence of Crack Propagation on Static and Dynamic
    J. Appl. Environ. Biol. Sci. , 5(12S )142 -150 , 2015 ISSN: 2090-4274 Journal of Applied Environmental © 2015, TextRoad Publication and Biological Sciences www.textroad.com Investigation of Influence of Crack Propagation on Static and Dynamic Behavior of Concrete Dams using Extended Finite Element Method due to Water Level Fluctuation during Earthquake Mir Ahmad Lashteh Neshaei1 and Morteza Khomami Abadi 2 and Rasoul Vahedzadegan 3 1 Associate Professor, Civil Engineering Department, University of Guilan 2 MSC Student, Civil Engineering Department, University of Guilan, Iran; 3 BSC Student, Mechanical Engineering Department, University of Azad Anzali, Iran; Received: July24, 2015 Accepted: September 31, 2015 ABSTRACT Water level fluctuation in concrete dams can have a significant effect on stress-strain behavior at different locations in the body of such structures. This effect is more pronounced when the earthquake induced forces are present. Sefidrud dam which is located in the north part of Iran, has suffered from the progressive crack development during the earthquake occurred in 1990 in that region. Creation of the longitudinal crack near the normal water level of the mentioned concrete dam while the reservoir was full has caused the motivation to investigate the effect of reservoir water level on crack development in the body of the dam. In this paper, using the data of the Rudbar-Manjil earthquake, the behavior of Sefidrud dam is modelled numerically and the effect of different reservoir water levels on generation and development of crack in the body of the dam is investigated. The relation between the water level and dimension of crack is empirically estimated and verified using the real field measurements indicating a good agreement.
    [Show full text]
  • The Study on Integrated Water Resources Management for Sefidrud River Basin in the Islamic Republic of Iran
    WATER RESOURCES MANAGEMENT COMPANY THE MINISTRY OF ENERGY THE ISLAMIC REPUBLIC OF IRAN THE STUDY ON INTEGRATED WATER RESOURCES MANAGEMENT FOR SEFIDRUD RIVER BASIN IN THE ISLAMIC REPUBLIC OF IRAN Final Report Volume III Supporting Report November 2010 JAPAN INTERNATIONAL COOPERATION AGENCY GED JR 10-122 WATER RESOURCES MANAGEMENT COMPANY THE MINISTRY OF ENERGY THE ISLAMIC REPUBLIC OF IRAN THE STUDY ON INTEGRATED WATER RESOURCES MANAGEMENT FOR SEFIDRUD RIVER BASIN IN THE ISLAMIC REPUBLIC OF IRAN Final Report Volume III Supporting Report November 2010 JAPAN INTERNATIONAL COOPERATION AGENCY THE STUDY ON INTEGRATED WATER RESOURCES MANAGEMENT FOR SEFIDRUD RIVER BASIN IN THE ISLAMIC REPUBLIC OF IRAN COMPOSITION OF FINAL REPORT Volume I Main Report Volume II Summary Volume III Supporting Report Currency Exchange Rate used in this Report: USD 1.00 = RIAL 9,553.59 = JPY 105.10 JPY 1.00 = RIAL 90.91 EURO 1.00 = RIAL 14,890.33 (As of 31 May 2008) Location Map of the Study Area (i) CTI Engineering International Co., Ltd. ABBREVIATION Abbreviation : English C/P : Counterpart DB : Database DOE : Department of Environment DF/R : Draft Final Report DIC/R : Draft Inception Report EHC : Environmental High Council F/R : Final Report FAO : Food and Agriculture Organization GDP : Gross Domestic Product GIS : Geographical Information System GIS-DB : Geographical Information System Database GRDP : Gross Regional Domestic Product IEE : Initial Environmental Examination IC/R : Inception Report IRIMO : Isramic Republic of Iram Meteorological Organization IT/R :
    [Show full text]