1 SOIL-STRUCTURE INTERACTION, WAVE PASSAGE EFFECTS AND ASSYMETRY IN NONLINEAR SOIL RESPONSE Mihailo D. Trifunac Civil Eng. Department University of Southern California, Los Angeles, CA URL:
2 INTRODUCTION To design structures for dynamic loads, the engineer begins by creating a model representation of the prototype. This model will form the basis for all subsequent analyses, and it will be used to write the governing equations, to describe the structure by discrete or continuous parameters, and to compute the quantities required for design. Thus, this model must have the properties that will describe the response of the prototype as completely and as accurately as possible. The search for a good model is therefore the first and the most important step preceding the analysis and design processes. After the model has been specified, the engineer can analyze, design, and test only that part of the representation of the real structure that the adopted model is capable of representing.
3 MODELING The forward analyses include only the first three steps (within the dashed box): (1) idealization of real structures, (2) mathematical modeling, and (3) analysis of response. The iterative learning process involves two additional tasks: (4) full-scale experimental verification, and (5) revision of the previously adopted models. In the following, we discuss some of those and illustrate their roles by reviewing examples from our previous work. Other modeling issues will involve consideration of simple versus detailed models, reduction of the degrees of freedom, linear versus nonlinear analysis, various forms of dynamic coupling, dissipation mechanisms, soil-structureinteraction, and completeness in representation of strong ground motion.
4 Simple versus detailed models (a, left) Equivalent SDOF system supported by flexible soil. (b, right) MDOF on independent spread footings on elastic soil. A structure responding to long-period (long-wave) dynamic loads, mainly in its first mode of vibration, could be represented by a single-degree-of-freedom (SDOF) system as shown in Fig. a. The same structure excited by high-frequency (shortwaves) dynamic loads will have to be represented by a detailed (continuous or discrete, 2-D or 3-D) model, which is capable of representing relative deformations and the associated forces within the structure (Fig. b), and which is best formulated in terms of the wave propagation approach.
5 In the example shown at left, the deformation of the structure can be specified by only one coordinate and can be described by a one-dimensional wave equation. For structures with smaller height-to-width ratios and with non-uniform distribution of stiffness (right), the use of 2- or 3-D models and wave propagation analysis will offer advantages over vibrational formulation of response, or may be the only alternative.
6 Soil-structure interaction Analysis of soil-structure interaction requires additional degrees of freedom, and depending on the model it may call for the method of solutions in terms of wave propagation. In general terms, soil-structure interaction will lengthen the apparent period of the system, will increase the relative contribution of rocking excitation of ground motion to the total response, and will usually reduce the maximum base shear. Advantages of including soil-structure interaction in the design result from the scattering of incident waves from the body of the foundation and from additional radiation of structural vibration energy into the soil. When the soil surrounding the foundation experiences small-to-modest levels of nonlinear response, soil-structure interaction will lead to significant energy loss of the input wave energy. Since this energy loss occurs outside the structure, if will be one of the important challenges for the future design of safe structures to quantify this loss and to exploit it.
7 FULL-SCALE EXPERIMENTAL VERIFICATION The laboratory tests can be useful, but are never as complete as full-scale experiments. Even the most carefully and completely planned laboratory work will represent only those aspects of the problem that the experimenter chose to study and that were incorporated into the model. That is, the best and the most complete laboratory tests can be used to verify and quantify mainly those aspects of the problem that the investigator knows. Except when fortunate accidents occur, we do not know how to model what we are not aware of and what we do not understand. The full-scale tests present a completely different set of practical problems, but the as-built environment contains all of the physical properties of reality. We only have to find ingenuous ways to discover, record, and interpret them. Another point is that the physical completeness and reality of the full-scale structures is necessary, but not sufficient, to guarantee the correct end results. The discovery and understanding of the true nature of response tend to be born by the difficult labor involving reconciliation between our imperfect theories, modeling, and analyses, with often incomplete data from the measurements. Experienced experimentalists know that the first test rarely produces results, as we inevitably forget to measure something, or what we measure does not turn out to be useful. Thus, iterations are almost a rule, in both experiments and in the analyses.
8 STRONG GROUND MOTION Strong motion includes translational and rotational propagating excitations which all contribute to the total response. Consideration of only horizontal motion can seriously underestimate the total response.
9 WAVE PASSAGE WILL CHANGE AND AMPLIFY RELATIVE RESPONSE
10 Amplification of relative response of SDOF by wave passage for half transit times equal to 0.005, 0.01, 0.02, 0.05, 0.07, and 0.1 s
11 The transit times in the previous figure are the times it takes the wave with horizontal phase velocity C to propagate across one half of the length of the structure. The phase velocity C depends on the wave type. For body waves it is a function of their incident angle, and for surface waves it is determined by the corresponding dispersion curve of the surface wave mode. Assuming that the seismic wave energy arrives vertically results in (1) Infinite values of C, (2) the transit time equal to zero, and (3) reduction of 2D representation to 1D representation of the physical nature of the problem. Remembering that 70% to 80% of strong motion wave energy arrives at the site as surface waves, and that for small epicentral distances it is not likely that the body waves will arrive vertically towards the site, it should be clear that 1D representation of excitation by vertically incident strong motion waves is not realistic.
12 NONLINAR SSI WILL RESULT IN ASYMETRIC PRMANENT STRAINS IN THE SOIL FOR NONVERTICAL WAVE INCIDENCE In this example we consider elasto-plastic soil and linear foundation and building response. We excite the soil by non-vertically incident SH wave pulse and employ finite differences (FD) to calculate the response.
13 Permanent displacements (left) and strains (right) in the soil for small (C = 1.73), intermediate (C = 1.5), and large nonlinearity (C = 0.8). The angle of incidence is 30 degrees from vertical, the amplitude of the pulse is A = 0.05m, and the dimensionless frequency is 1.5. The properties of the three media (SH wave velocity, density, width, height) are: nonlinear soil (250 m/s, 2000 kg/m³, 95.5 m, m), linear rectangular foundation (500 m/s, 2000 kg/m³, 19.1 m, 9.55 m), and linear building (100 m/s, 270 kg/m³, 19.1 m, m).
14 Principal permanent strain in the soil for h = 0.1, two angles of incidence, three foundation stiffnesses, and intermediate nonlinearity C = 1.5.
15 Reduction of wave energy entering the linear building and linear foundation for different levels of soil nonlinearity (C = 0.8, 0.9, 1.1, 1.3, 1.5, and 1.73) and for different foundation rigidities expressed via shear wave velocity in the foundation equal to 250, 300, 500, and 1000 m/s.
16 Reduction of wave energy entering the linear building and linear foundation by scattering, for different levels of soil nonlinearity (C = 0.8, 0.9, 1.1, 1.3, 1.5, and ) and for different foundation rigidities expressed via shear wave velocity in the foundation 300, 500, and 1000 m/s.
17 Asymmetric permanent strains in the soil will lead to amplification of the effective torsional and rocking excitations, and as precursors of liquefaction can create conditions for asymmetry in effective compliances in SSI. With progression of large amplitudes of excitation a combination of those effects will facilitate faster transition to large nonlinear response and to collapse. In the following I show some observational evidence for asymmetry of response and for nonlinearities in the response of soils during SSI.
18 Hollywood Storage Building
19 Hollywood Storage Bldg. This building was not damaged by any of the earthquakes since 1934, but displays large changes in system frequencies. The observed range of smallest to largest frequencies is 1.9 (for EW) to 2.3 (for NS), so far. Relative to the first recording, system frequencies have increased up to 33% (for NS) and decreased 62% (for EW). Largest drop of system frequency during a single earthquake was 69% (from Trifunac et al. 2001).
20 Van Nuys seven story hotel VN7SH
21 Van Nuys Hotel (VN7SH) VN7SH was damaged by San Fernando 1971, and Northridge 1994 earthquakes. From 1966 to 1994 it displayed large changes in system frequencies. The observed range of smallest to largest frequencies is 3.6 (for NS response). Relative to the first recording, system frequencies have increased up to 68% (for NS) and decreased 47% (for EW). The largest drop of system frequency during a single earthquake was 44% (from Trifunac et al. 2001).
22 Changes in system frequencies Change in system frequencies may be due to change of stiffness of the structure, or of the soil, or of the foundation, or of all of the above. The energy of response is concentrated around the frequencies of the soil-structure system. Therefore, Fourier analyses give the system frequencies, which depend on the properties of the soil, structure and foundation. Majority of studies neglect or ignore the soil structure interaction and thus are based on monitoring changes in the system frequency. This leads to erroneous results except when soil structure interaction effects are small, which is rare for typical buildings.
23 Full-scale observations in buildings have shown that the system frequencies drop during strong shaking, but recover partially or totally. Recoverable changes, not related to damage, can reach and exceed 20% (Udwadia and Trifunac 1974, Trifunac et al. 2001a,b; Todorovska et al. 2006). Most methods for structural identification require separation of the effects of the soil on the measured frequencies of vibration and their changes - i.e. require the structural fixed-base frequency. Other applications may require monitoring of changes of the soilfoundation system i.e. require the rigid-body frequencies.
24 Asymmetry of response of Van Nuys Building
25 Contours of NS motion (normalized amplitudes, shown by heavy lines), and time delays (in seconds) relative to the reference station at B2.
26 The foundation system of VN7SH consists of 38 inch deep pile caps, supported by groups of two to four poured-in-place 24 inch diameter reinforced concrete friction piles. These are centered under the main building columns. All pile caps are connected by a grid of the beams. Each pile is roughly 40 feet long and has design capacity of over 100 kips vertical load and up to 20 kips lateral load. The entire foundation system was designed to be symmetric relative to both longitudinal and transverse axes of this building. We discovered large eccentricity in the response of this building during ambient vibration tests following the Northridge earthquake of Subsequent studies of the recorded earthquake responses in this building have confirmed the presence of this asymmetry during all earthquakes following the San Fernando earthquake of 1971.
27 SUMMARY AND CONCLUSIONS Significant part of strong motion energy arrives at the site horizontally as surface waves, and for small epicentral distances and for shallow faulting, it is not likely that the body waves will arrive vertically. Consequently the 1D engineering representations of site excitation by vertically incident strong motion waves is neither realistic nor conservative. Asymmetric permanent strains in the soil will lead to amplification of the effective torsional and rocking excitations, and as precursors of liquefaction may create conditions for asymmetry in effective compliances in SSI. With progression of large amplitudes of excitation a combination of those effects will speed up the transition towards large nonlinear response and the collapse. Numerical models for engineering analyses of SSI must be capable to take as input realistic representations of strong motion waves, consisting of both body and surface waves, with arbitrary angles of incidence. These models must also be capable to model soil, foundation and the structure in the nonlinear range of response.
28 Many references on this subject can be downloaded from: Thank you for your attention
THE NATURE OF SITE RESPONSE DURING EARTHQUAKES Mihailo D. Trifunac Dept. of Civil Eng., Univ. of Southern California, Los Angeles, CA 90089, U.S.A. http://www.usc.edu/dept/civil_eng/earthquale_eng/ What
IDENTIFICATION OF FIXED-BASE AND RIGID BODY FREQUENCIES OF VIBRATION OF SOIL-STRUCTURE SYSTEMS FROM RECORDED RESPONSE WITH MINIMUM INSTRUMENTATION M.I. Todorovska 1 1 Research Professor, Dept. of Civil
3 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August -6, 24 Paper No. 354 SHAKING TABLE TEST OF STEEL FRAME STRUCTURES SUBJECTED TO NEAR-FAULT GROUND MOTIONS In-Kil Choi, Young-Sun
Fall Semester 2017 Problem 1 The simple structure shown below weighs 1,000 kips and has a period of 1.25 sec. It has no viscous damping. It is subjected to the impulsive load shown in the figure. If the
EVALUATING RADIATION DAMPING OF SHALLOW FOUNDATIONS ON NONLINEAR SOIL MEDIUM FOR SOIL-STRUCTURE INTERACTION ANALYSIS OF BRIDGES Abstract Jian Zhang 1 and Yuchuan Tang 2 The paper evaluates the radiation
Published in Davis, C.A., X. Du, M. Miyajima, and L. Yan (Ed.) International Efforts in Lifeline Earthquake Engineering, ASCE, TCLEE Monograph 38; pp. 592-599; doi: 10.1061/9780784413234.076; Copyright
Practice Name: Hour: Determining the Earthquake Epicenter: Japan Measuring the S-P interval There are hundreds of seismic data recording stations throughout the United States and the rest of the world.
Proc. 20 th NZGS Geotechnical Symposium. Eds. GJ Alexander & CY Chin, Napier Y Wang & R P Orense Department of Civil and Environmental Engineering, University of Auckland, NZ. email@example.com
Earthquakes Chapter 19 Does not contain complete lecture notes. What is an earthquake An earthquake is the vibration of Earth produced by the rapid release of energy Energy released radiates in all directions
Earthquakes Ch. 12 Dangerous tsunami threat off U.S. West Coast Earthquakes What is an Earthquake? It s the shaking and trembling of the Earth s crust due to plate movement. The plates move, rocks along
An Evaluation of the Force Reduction Factor in the Force-Based Seismic Design Gakuho Watanabe and Kazuhiko Kawashima Tokyo Institute of Technology, O-Okayama, Meguro, Tokyo, Japan, 5-55 ABSTRACT This paper
CE6701 STRUCTURAL DYNAMICS AND EARTHQUAKE ENGINEERING QUESTION BANK UNIT I THEORY OF VIBRATIONS PART A 1. What is mean by Frequency? 2. Write a short note on Amplitude. 3. What are the effects of vibration?
IN SITU TESTING TECHNOLOGY FOR FOUNDATION & EARTHQUAKE ENGINEERING Wesley Spang, Ph.D., P.E. AGRA Earth & Environmental, Inc. Portland, Oregon In situ testing of soil, which essentially consists of evaluating
SEISMIC BASE ISOLATION DESIGN OF BASE ISOLATION SYSTEMS IN BUILDINGS FILIPE RIBEIRO DE FIGUEIREDO SUMMARY The current paper aims to present the results of a study for the comparison of different base isolation
Outline of Continuous Systems. Introduction to Continuous Systems. Continuous Systems. Strings, Torsional Rods and Beams. Vibrations of Flexible Strings. Torsional Vibration of Rods. Bernoulli-Euler Beams.
CH Earthquakes Section 19.1: Forces Within Earth Section 19.2: Seismic Waves and Earth s Interior Section 19.3: Measuring and Locating Earthquakes Section 19.4: Earthquakes and Society Section 19.1 Forces
Structural Control and Health Monitoring, 2009, in press Earthquake Damage Detection in the Imperial County Services Building II: Analysis of Novelties via Wavelets Maria I. Todorovska 1 and Mihailo D.
Pseudo-natural SSI frequency of coupled soil-pilestructure systems E.N. Rovithis Institute of Engineering Seismology and Earthquake Engineering (ITSAK), Thessaloniki, Greece K.D. Pitilakis Department of
Procedia Engineering Volume 143, 216, Pages 522 529 Advances in Transportation Geotechnics 3. The 3rd International Conference on Transportation Geotechnics (ICTG 216) Experimental Study on Damage Morphology
NPTEL Video Course on Geotechnical Earthquake Engineering by Prof. Deepankar Choudhury Professor, Dept. of Civil Engg., Indian Institute of Technology (IIT) Bombay Powai, Mumbai 400076, India. Email: firstname.lastname@example.org
1 7 SEISMIC LOADS 7.1 Estimation of Seismic Loads 7.1.1 Seismic load and design earthquake motion (1) For ordinary buildings, seismic load is evaluated using the acceleration response spectrum (see Sec.7.2)
1. Introduction Nowadays, the seismic verification of structures has dramatically evolved. Italy is surrounded many great earthquakes; hence it would be unwise to totally ignore the effects of earthquakes
Pushover Seismic Analysis of Bridge Structures Bernardo Frère Departamento de Engenharia Civil, Arquitectura e Georrecursos, Instituto Superior Técnico, Technical University of Lisbon, Portugal October
3 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August - 6, 2004 Paper No. 2386 CHARACTERISTICS OF SITE-SPECIFIC AMPLIFIACTION FUNCTIONS MEASURED IN MONTENEGRO Sanja S. IVANOVIC
Earthquakes http://thismodernworld.com/comic-archive Elastic rebound http://projects.crustal.ucsb.edu/understanding/elastic/rebound.html Elastic rebound Rocks store energy elastically When stored stress
Dynamic Analysis of a Reinforced Concrete Structure Using Plasticity and Interface Damage Models I. Rhee, K.J. Willam, B.P. Shing, University of Colorado at Boulder ABSTRACT: This paper examines the global
4 th International Conference on Earthquake Geotechnical Engineering June 25-28, 2007 Paper No. 1445 THE ROLE OF THE AMPLITUDE AND FREQUENCY CONTENT OF THE INPUT GROUND MOTION ON THE ESTIMATION OF DYNAMIC
565 PHASE ANGLE PROPERTIES OF EARTHQUAKE STRONG MOTIONS: A CRITICAL LOOK B TILIOUINE 1, M HAMMOUTENE And P Y BARD 3 SUMMARY This paper summarises the preliminary results of an investigation aimed at identifying
, June 29 - July 1, 216, London, U.K. Periodic Material-based Design of Seismic Support Isolation for Industrial Facilities Witarto Witarto, S. J. Wang, Y. L. Mo, K. C. Chang, Yu Tang, and Robert P. Kassawara
A SUDY ON IMPROVEMEN OF PUSHOVER ANALYSIS Pu YANG And Yayong WANG SUMMARY he static pushover analysis, POA, is becoming popular as a simplified computer method for seismic performance evaluation of structures.
Nonlinear Analysis of Viaducts and Overpasses Geotechnical Modeling Issues Steve Kramer Pedro Arduino Hyung-Suk Shin University of Washington The Problem Approach Soil Soil Soil Soil Soil Soil Soil Soil
Inelastic shear response of RC coupled structural walls E. Morariu EDIT Structural, Bucuresti, Rumania. T. Isakovic, N. Eser & M. Fischinger Faculty of Civil and Geodetic Engineering, University of Ljubljana,
Harmonized European standards for construction in Egypt EN 1998 - Design of structures for earthquake resistance Jean-Armand Calgaro Chairman of CEN/TC250 Organised with the support of the Egyptian Organization
3 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August -6, 004 Paper No. 308 NON-LINEAR VISCOELASTIC MODEL OF STRUCTURAL POUNDING Robert JANKOWSKI SUMMARY Pounding between structures
Proceedings of the Ninth Pacific Conference on Engineering Building an -Resilient Society 14-16 April, 011, Auckland, New Zealand Seismic pounding of bridge superstructures at expansion joints B. Lindsay,
Seismic Pushover Analysis Using AASHTO Guide Specifications for LRFD Seismic Bridge Design Elmer E. Marx, Alaska Department of Transportation and Public Facilities Michael Keever, California Department
http://intranet.dica.polimi.it/people/boffi-giacomo Dipartimento di Ingegneria Civile Ambientale e Territoriale Politecnico di Milano April 21, 2017 Outline of Structural Members Elastic-plastic Idealization
Ministry of Municipal Affairs PROPOSED CHANGE TO THE 2012 BUILDING CODE O. REG. 332/12 AS AMENDED CHANGE NUMBER: SOURCE: B-04-01-15 Ontario-NBC CODE REFERENCE: Division B / 126.96.36.199. Division B / 188.8.131.52.
Rotating Machinery, 10(4): 283 291, 2004 Copyright c Taylor & Francis Inc. ISSN: 1023-621X print / 1542-3034 online DOI: 10.1080/10236210490447728 Deflections and Strains in Cracked Shafts due to Rotating
Directing Energy Dissipation in Earthquake-Soil-Structure Systems, Nima Tafazzoli, Mahdi Taiebat, Guanzhou Jie Department of Civil and Environmental Engineering University of California, Davis CompDyn9
Chapter 19 Earthquakes Shake, Rattle & Roll 19.1 Forces within OBJECTIVES Define stress and strain as they apply to rocks. Distinguish among the three different fault types. Contrast three types of seismic
Journal of Physics: Conference Series Damping of materials and members in structures To cite this article: F Orban 0 J. Phys.: Conf. Ser. 68 00 View the article online for updates and enhancements. Related
Elastic rebound theory Focus epicenter - wave propagation Dip-Slip Fault - Normal Normal Fault vertical motion due to tensional stress Hanging wall moves down, relative to the footwall Opal Mountain, Mojave
Volume B 3.1.4 Diaphragmatic behaviour In general, when there is eccentric loading at a floor, e.g. imposed by the horizontal seismic action, the in-plane rigidity of the slab forces all the in-plane points
STUDY OF THE BEHAVIOR OF PILE GROUPS IN LIQUEFIED SOILS Shin-Tower Wang 1, Luis Vasquez 2, and Lymon C. Reese 3, Honorary Member,, ASCE ABSTRACT : 1&2 President & Project Manager, Ensoft, Inc. Email: email@example.com
Module 4 : Deflection of Structures Lecture 4 : Strain Energy Method Objectives In this course you will learn the following Deflection by strain energy method. Evaluation of strain energy in member under
Contents i Contents 7 SEISMIC LOADS Commentary 7. Estimation of Seismic Loads.............................. 7.. Seismic load and design earthquake motion.................. 4 7..2 Idealization of building
University of California Peer Reviewed Title: Damage Identification Study of a Seven-story Full-scale Building Slice Tested on the UCSD-NEES Shake Table Author: Moaveni, Babak, Tufts University He, Xianfei,
PEAT8002 - SEISMOLOGY Lecture 12: Earthquake source mechanisms and radiation patterns II Nick Rawlinson Research School of Earth Sciences Australian National University Waveform modelling P-wave first-motions
13 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August 1-6, 24 Paper No. 3298 SEISMIC DEFORMATION ANALYSIS OF AN EARTH DAM - A COMPARISON STUDY BETWEEN EQUIVALENT-LINEAR AND NONLINEAR
01/02/2016 Marco Donà Finite Element Modelling with Plastic Hinges 1 Plastic hinge approach A plastic hinge represents a concentrated post-yield behaviour in one or more degrees of freedom. Hinges only
Name Date Class Earthquakes Section Summary Forces in Earth s Crust Guide for Reading How does stress in the crust change Earth s surface? Where are faults usually found, and why do they form? What land
ecture 8: lexibility Method Example The plane frame shown at the left has fixed supports at A and C. The frame is acted upon by the vertical load P as shown. In the analysis account for both flexural and
Analyses of Soil-Structure Systems Julio García Paul C. Rizzo Associates, Inc., 105 Mall Blvd. Suite 270E, Monroeville, PA 15146, USA Phone: +1 (412)856-9700, Fax: +1 (412)856-9749, Email: firstname.lastname@example.org
8 th International Conference on Behavior of Steel Structures in Seismic Areas Shanghai, China, July 1-3, 2015 COLUMN BASE WEAK AXIS ALIGNED ASYMMETRIC FRICTION CONNECTION CYCLIC PERFORMANCE J. Borzouie*,
Shock and Vibration 19 (2012) 1061 1069 1061 DOI 10.3233/SAV-2012-0712 IOS Press Model tests and FE-modelling of dynamic soil-structure interaction N. Kodama a, * and K. Komiya b a Waseda Institute for
NEAR-FAULT GROUND MOTIONS: Outstanding Problems APOSTOLOS S. PAPAGEORGIOU University of Patras Outline Characteristics of near-fault ground motions Near-fault strong ground motion database A mathematical
Wang, S. & Orense, R.P. (2013) Proc. 19 th NZGS Geotechnical Symposium. Ed. CY Chin, Queenstown S Wang Beca Consultants, Wellington, NZ (formerly University of Auckland, NZ) Jackson.email@example.com R P Orense
PLAT DAN CANGKANG (TKS 4219) SESI I: PLATES Dr.Eng. Achfas Zacoeb Dept. of Civil Engineering Brawijaya University INTRODUCTION Plates are straight, plane, two-dimensional structural components of which
his paper was presented at the Uzumeri Symposium during the 2000 Fall ACI Annual Convention in oronto, October 6, 2000, in oronto, Canada. he paper will be published in an ACI Special Publication Volume.
4 th IASPEI / IAEE International Symposium: Effects of Surface Geology on Seismic Motion August 23 26, 2011 University of California Santa Barbara EFFECTS OF TOPOGRAPHIC POSITION AND GEOLOGY ON SHAKING
ELASTIC LIMIT EARTHQUAKES Bend sitck but do not break it. What do you notice? No bend until it breaks. Describe the energy and forces at work. (Kinetic, potential etc) 8 TH GRADE FAULT FORCE AND PLATES
STRUCTURAL CONTROL USING MODIFIED TUNED LIQUID DAMPERS A. Samanta 1 and P. Banerji 2 1 Research Scholar, Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, India, 2 Professor,
Behavior and Modeling of Existing Reinforced Concrete Columns Kenneth J. Elwood University of British Columbia with contributions from Jose Pincheira, Univ of Wisconsin John Wallace, UCLA Questions? What
Chapter 7: Solving Structural Dynamic Problems Using DCALC By Karl Hanson, S.E., P.E.* September 2008 7.1 Introduction: The last chapter presented the fundamental methods used in structural dynamics to
www.crl.issres.net Vol. 4 (1) March 2013 Finite Element and Modal Analysis of 3D Jointless Skewed RC Box Girder Bridge Mahmoud Sayed-Ahmed c, Khaled Sennah Department of Civil Engineering, Faculty of Engineering,
A NEW DEFINITION OF STRONG MOTION DURATION AND RELATED PARAMETERS AFFECTING THE RESPONSE OF MEDIUM-LONG PERIOD STRUCTURES I.M. Taflampas 1, C.C. Spyrakos 2 and Ch.A. Maniatakis 3 1 Civil Engineer, Dept.
4 5000 4000 (increased d ) (increased f (increased A s or f y ) c or b) Flexure: Behavior and Nominal Strength of Beam Sections Moment (kip-in.) 3000 2000 1000 0 0 (basic) (A s 0.5A s ) 0.0005 0.001 0.0015
DETERMINATION OF DUCTILITY CAPACITY AND OTHER SECTION PROPERTIES OF T-SHAPED RC WALLS IN DIRECT DISPLACEMENT-BASED DESIGN E. Smyrou 1, T.J. Sullivan 2, M.J.N. Priestley 3 and G.M. Calvi 4 1 PhD Candidate,
Multi-station Seismograph Network Background page to accompany the animations on the website: IRIS Animations Introduction One seismic station can give information about how far away the earthquake occurred,
1 Introduction QUAKE/W Comparison is a commercially available software product for doing one-dimensional ground response analyses. It was developed and is being maintained under the guidance of Professor
Comparison between the visco-elastic dampers And Magnetorheological dampers and study the Effect of temperature on the damping properties A.Q. Bhatti National University of Sciences and Technology (NUST),
EXTENDED ABSTRACT Combined Pile Raft Foundation Rui Diogo Gomes da Silva Supervisor: Prof. Jaime Alberto dos Santos December 2009 1. Introduction The piled raft foundation is an innovative design concept
Seismic Stability of Tailings Dams, an Overview BY Gonzalo Castro, Ph.D., P.E. Principal International Workshop on Seismic Stability of Tailings Dams Case Western Reserve University, November 2003 Small
13 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August 1-6, 24 Paper No. 2367 CAPACITY DESIGN FOR TALL BUILDINGS WITH MIXED SYSTEM M.UMA MAHESHWARI 1 and A.R.SANTHAKUMAR 2 SUMMARY
Effect of lateral load on the pile s buckling instability in liquefied soil Xiaoyu Zhang 1, Liang Tang 2, Xianzhang Ling 3 and Andrew H. C. Chan 4 1. Corresponding Author. Ph. D. Candidate, School of Civil
EARTHQUAKE SIMULATION TESTS OF BRIDGE COLUMN MODELS DAMAGED DURING 1995 KOBE EARTHQUAKE J. Sakai 1, S. Unjoh 2 and H. Ukon 3 1 Senior Researcher, Center for Advanced Engineering Structural Assessment and
Source Wave Design for Downhole Seismic Testing Downhole seismic testing (DST) has become a very popular site characterizing tool among geotechnical engineers. DST methods, such as the Seismic Cone Penetration
Ratio: Theoretical Aspect and Measurement Sri Atmaja P. Rosyidi, Ph.D. Assistant Professor, Universitas Muhammadiyah Yogyakarta A Two Day Workshop on SASW for Practicing Engineer 17-18 February 2011, Faculty
Liquefaction Fundamentals Page 1 Liquefaction Fundamentals Homework Assignment Design Earthquake: All problems below is a M = 7.0 earthquake with pga of 0.63 g and a source distance Rrup = 4 km. 1. Use
USER S MANUAL 1D Seismic Site Response Analysis Example http://www.soilquake.net/ucsdsoilmodels/ University of California: San Diego August 2, 2017 Table of Contents USER'S MANUAL TABLE OF CONTENTS Page
CE 543 Structural Dynamics Introduction Dynamic Loads Dynamic loads are time-varying loads. (But time-varying loads may not require dynamic analysis.) Dynamics loads can be grouped in one of the following