Seismic Design of Bridges After 1995 Kobe Earthquake

2006 ◽  
Vol 1 (2) ◽  
pp. 262-271 ◽  
Author(s):  
Kazuhiko Kawashima ◽  
Keyword(s):  
Seismic Design ◽  
Near Field ◽  
The United States ◽  
Ground Movement ◽  
Response Analysis ◽  
Design Codes ◽  
Design Philosophy ◽  
Kobe Earthquake ◽  
Nonlinear Static ◽  
Recent Earthquakes

The 1995 Kobe earthquake extensively damaged bridges and triggered research and review as a consequence of recent earthquakes that have led to significant advances in bridge seismic design. This paper presents how this has affected design philosophy and design codes in Japan compared to seismic design codes in EC, New Zealand, and the United States concerning design philosophy, near-field ground motions, design force and ductility requirements, linear/nonlinear static/dynamic response analysis, and treatment of liquefaction and liquefaction-induced lateral ground movement.

scholarly journals Seismic design and retrofit of bridges

2000 ◽  
Vol 33 (3) ◽  
pp. 265-285 ◽  
Author(s):  
Kazuhiko Kawashima
Keyword(s):  
New Zealand ◽  
Ground Motion ◽  
Seismic Design ◽  
Near Field ◽  
Concrete Columns ◽  
Seismic Retrofitting ◽  
Ground Movement ◽  
Design Codes ◽  
Japanese Experience ◽  
Nonlinear Static

The 1989 Loma Prieta, 1994 Northridge and 1995 Hyogo-ken nanbu earthquakes caused major damage to bridges and these events together with the research triggered as a consequence of the earthquakes has led to significant advances in bridge seismic design and retrofitting. This paper presents how this has affected design philosophies and design codes in EC, New Zealand, Japan and USA in recent years, with emphasis on the Japanese experience in the aftermath of the 1995 H-k-n earthquake. Near field ground motion, linear/nonlinear static/dynamic response analyses, treatment of liquefaction-induced lateral ground movement are described. Comparison of design philosophy, design force and ductility requirements are compared among the EC-8, New Zealand, Japanese, AASHTO and Caltrans/ATC-32 codes. Seismic retrofitting which was conducted in Japan after the Hyogo-ken nanbu earthquake over 29,000 reinforced concrete columns is described.

Introduction to Dr. Iwasaki’s Paper Entitled “Response Analysis of Civil Engineering Structures Subjected to Earthquake Motions”

2006 ◽  
Vol 1 (2) ◽  
pp. 272-273
Author(s):  
Kazuhiko Kawashima ◽  
Keyword(s):  
Ground Motion ◽  
Seismic Design ◽  
Safety Evaluation ◽  
Soil Liquefaction ◽  
Response Analysis ◽  
Design Codes ◽  
Kobe Earthquake ◽  
Seismic Design Code ◽  
Liquefaction Assessment ◽  
Extensive Damage

Seismic design of Japanese bridges started in 1925, triggered by the extensive damage of the 1923 Kanto earthquake. "Drafted Structural Details of Road Structures," issued by Japan's Ministry of the Interior in 1925, recommended the use of static seismic analysis based on working stress design, which was used for a long time. "Design Specifications of Steel Bridges," issued by the Japan Road AssoCiation in 1964, was an important code used for design of a number of bridges during restoration after World War II and the early high economic growth periods that followed. There was no independent seismic design code in those days, so only limited descriptions were provided for seismic design, e.g., pages in the code related to seismic design numbered only 2 or 3, and seismic knowledge was limited. Most bridges damaged in the 1995 Kobe earthquake were designed based on this code. Extensive damage in the 1964 Niigata earthquake initiated intensified research on the structural response and seismic design of bridges. Accomplishments of research were reflected in the 1971 "Guide Specifications on Seismic Design of Bridges" (Japan Road Association), the first design guidelines focusing on the seismic design of bridges. Pages of the main text and explanations related to seismic design increased to 30, and included the natural period dependent lateral seismic coefficient and preliminary evaluation of soil liquefaction assessment and unseating prevention devices. This was the first time that preliminary liquefaction assessment and unseating prevention devices innovated by Japanese bridge engineers were included in bridge codes. The 1971 Guide Specification of Seismic Design of Bridges was compiled with other design codes and issued in 1980 as "Part V Seismic Design" of "Design Specifications of Highway Bridges" (Japan Road Association). Assessment of soil liquefaction based on FL was introduced in Part V, but other parts remained almost unchanged. Part V was completely revised in 1990 to include (1) new static analysis evaluating lateral force in continuous bridges based on the stiffness of superstructures and substructures, (2) safety evaluation (level 2) ground motion for the design of reinforced concrete columns, and (3) design response spectra and design-spectra-compatible ground acceleration for dynamic response analysis. This was the first in Japan to include safety evaluation ground motion and static design for ductility evaluation of bridge columns. Pages on code related to seismic design increased to 96 greatly enhanced as a modern seismic design code. Based on the extensive damage sustained in the 1995 Kobe earthquake, Part V on seismic design was further revised in 1996 and 2002 to include lessons learned from this damage. Pages of code related to seismic design increased to 227 in the 1996 code and 280 in the 2002 code. Figure 1 shows the increase in the number of pages related to seismic design. Extensive improvement was conducted in 1990 and 1996. Although we have had over 80 years in experience of seismic bridge design, only in the last 15 years has seismic bridge design been enhanced to include modern requirements. Codes before the 1971 Guide Specification and the 1980 Part V on seismic design had insufficient scientific knowledge, although they were used for design in a number of bridges. The paper by Dr. Iwasaki has contributed much to establishing modern seismic design codes for bridges. His contributions include, but are not limited to, the clarification of dynamic response characteristics of bridges based on extensive field measurements, the deployment of strong motion recording networks, the development of soil liquefaction evaluation based on FL, and the development of ground motion attenuation equations. All of his activities and research helped enhance seismic design codes for bridges in Japan.

New Seismic Design Specifications of Highway Bridges in Japan

1994 ◽  
Vol 10 (2) ◽  
pp. 333-356 ◽  
Author(s):  
Kazuhiko Kawashima ◽  
Kinji Hasegawa
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Response ◽  
Seismic Design ◽  
Structural Response ◽  
Highway Bridges ◽  
Lateral Force ◽  
Inertia Force ◽  
Response Analysis ◽  
Design Specifications ◽  
Recent Earthquakes

This paper presents the new seismic design specifications for highway bridges issued by the Ministry of Construction in February 1990. Revisions of the previous specifications were based on the damage characteristics of highway bridges that were developed after the recent earthquakes. The primary revised items include the seismic lateral force, evaluation of inertia force for design of substructures considering structural response, checking the bearing capacity of reinforced concrete piers for lateral load, and dynamic response analysis. Emphasis is placed on the background of the revisions introduced in the new seismic design specifications.

Problems and Suggestions of Chinese Highway Bridge Seismic Design

2013 ◽  
Vol 574 ◽  
pp. 127-134
Author(s):  
Xiu Yun Gao ◽  
Shao Yi Zhang
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Highway Bridges ◽  
Developed Countries ◽  
The United States ◽  
Highway Bridge ◽  
Design Codes ◽  
New Codes ◽  
Single Standard ◽  
The Developed Countries

The seismic design of Chinese Highway Bridge changed from single standard of fortification and one-step design performed nearly two decades to two-level fortification and two-stage design with the introduction of the new codes in 2008 and 2011. However, there are some shortcomings of the new codes such as the choice of response spectrum type, the determination of reinforced concrete constitutive relation, the discrimination of site-type and the bearing checking items, which leave a large room for improvement. Combined with the design codes of the developed countries like Japan and the United States, some useful suggestions are put forward in this paper for Chinese existing design codes. It is believed that Chinese seismic levels can be significantly increased so long as highway bridges are designed in accordance with the improved codes.

scholarly journals PERFORMANCE ANALYSIS OF BUILDING STRUCTURE ASRAMA PUTRI ACEH WEST LOAD ON KOBE EARTHQUAKE

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Andi Yusra ◽  
Aulia Rahman
Keyword(s):  
Performance Analysis ◽  
Earthquake Response ◽  
Response Analysis ◽  
Building Structure ◽  
Kobe Earthquake ◽  
Nonlinear Static ◽  
Earthquake Response Analysis ◽  
Banda Aceh

Perencanaan struktur bangunan di Indonesia haruslah memiliki ketahanan yang baik dikarenakan sebagian besar wilayahnya memiliki tingkat kerawanan yang tinggi terhadap gempa.salah satunya Provinsi Aceh yang tergolong pada daerah paling rawan gempa, itulah sebabnya mengapa perencanaan struktur     yang baik sangatlah di butuhkan. Analisis dilakukan dengan tujuan untuk mengevaluasi  kinerja  struktur  terhadap  perencanaan,  dan  membandingkan  hasil  analisis  untuk menguji daya tahan sebuah gedung dengan cara menganalisis besarnya Displacement yang terjadi pada saat berlangsungnya gempa, dengan menggunakan metode 3D nonlinear earthquake response analysis (Respon Spektrum) dan metode 3D nonlinear static push-over analysis sebagai pembanding untuk mendapatkan hasil akurasi yang baik dengan tujuan untuk mengetahui besarnya tingkat resiko yang  akan  dialami  oleh  gedung  tersebut.  Dengan  harapan  nantinya  setiap  gedung  yang  akan dibangun  atau  gedung-gedung  yang sudah lama  dan  sudah terkena  dampak bencana  gempa  di kawasan-kawasan  yang  rawan  gempa seperti  di  Aceh,  juga  dilakukan  analisis  terhadap  struktur bangunannya agar didapat bangunan yang aman,kuat, kokoh, dan tahan terhadap gempa. Dalam analisis ini gedung yang akan penulis lakukan analisis terhadap strukturnya adalah gedung Asrama Putri Aceh Barat, Komplek Asrama IPELMABAR, Lamreung Banda Aceh. Gedung tersebut telah penulis lakukan desain ulang dari 3 lantai menjadi 4 lantai guna untuk memenuhi syarat Tugas Akhir Analisis gedung.Analisis yang akan penulis lakukan menggunakan aplikasi STERA 3D dimana Perangkat lunak ini dikembangkan untuk menganalisis struktur bangunan terhadap gempa. Mudah- mudahan  dengan  aplikasi  ini  nantinya  penulis  lebih  mudah  untuk  melakukan  analisis  terhadap struktur gedung yang akan penulis lakukan analisis terhadap strukturnya. Kata Kunci :     Analisis Struktur, Bangunan

scholarly journals FEMA P695 methodology for safety margin evaluation of steel moment resisting frames subjected to near-field and far-field records

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Mahdi Heshmati ◽  
Alireza Khatami ◽  
Hamzeh Shakib
Keyword(s):  
Seismic Design ◽  
Ground Motions ◽  
Near Field ◽  
Safety Margin ◽  
Far Field ◽  
Performance Factors ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Nonlinear Static ◽  
Special Moment Resisting Frame

AbstractThis study presents the impact of near-field and far-field earthquakes on the seismic design of Intermediate Moment Resisting Frame (IMRF) and Special Moment Resisting Frame (SMRF) structures through FEMA (Federal Emergency Management Agency) P695 methodology to highlight the importance of probabilistic collapse as well as seismic performance factors of these structures. The purpose of this study is to investigate the collapse performance of steel intermediate and special moment resisting frame systems as the most common structural systems in urban areas in order to assess the seismic performance factors used for the design using nonlinear static and dynamic analysis methods. In this regard, as the representatives of low-rise to high-rise buildings, archetypes with 5-, 10- and 15- story of intermediate and special moment resisting frames are designed and then the nonlinear models are developed in OpenSees software. Nonlinear static analyses are performed to assess the overstrength and ductility of these systems. The effects of near-field and far-field ground motions on these frames are investigated through incremental dynamic analysis. These analyses are performed with 22 far-field and 20 near-field ground motion records using FEMA P695 methodology. The results show that near-field earthquakes have serious impacts on the collapse probability of structures. The superiority of special moment resisting frame over intermediate moment resisting frame is quantified in terms of safety margin and median collapse capacity under both near-field and far-field earthquakes. Finally, the results indicate that the response modification factors introduced in seismic design code are acceptable for intermediate moment resisting frame and special moment resisting frame under far-field ground motions. However, in the near-field sites while SMRF system meets the requirements of FEMA P695 methodology, the IMRF system does not satisfy these criteria.

scholarly journals Proposed Design Philosophy for Seismic-Resistant Buildings

2019 ◽  
Vol 21 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Nanang Gunawan ◽  
Aylie Han ◽  
Buntara Sthenly Gan
Keyword(s):  
Ultimate Strength ◽  
Seismic Design ◽  
Residential Buildings ◽  
Building Structures ◽  
Design Codes ◽  
Structural Elements ◽  
Plastic Deformations ◽  
Earthquake Loads ◽  
Design Philosophy ◽  
Comparative Results

Modern seismic design and technologies have undergone tremendous developments. In modern design codes, building structures subjected to high earthquake loads are allowed to experience plastic deformations without collapsing, and the design is permitted up to the ultimate strength. According to comparative results in Japan, the number of humans injured due to earthquakes is higher than the number of deaths/missing. Likewise, the number of residential buildings that collapsed are less than the partially damaged buildings. This outcome implies that residential buildings designed based on the revised seismic standards have good earthquake resistances. It also infers that the human deaths/injury casualties were not a result of the collapsed the structure, but due to the strong vibrations originated from the earthquake, yielding in the collapse of non-structural elements such as ceilings and bookshelves. This paper presents a proposed design philosophy that attempts to implement the effect of earthquakes to non-fatal human casualties

The Nexus Between Johannesburg Stock Exchange and the United States Unemployment Rate Announcement: An Impulse Response Analysis

2018 ◽  
Vol 10 (3(J)) ◽  
pp. 160-168
Author(s):  
Misheck Mutize ◽  
Victor Virimai Mugobo
Keyword(s):  
United States ◽  
South African ◽  
Impulse Response ◽  
Unemployment Rate ◽  
Stock Prices ◽  
Stock Exchange ◽  
The United States ◽  
Response Analysis ◽  
Johannesburg Stock Exchange ◽  
The Us

The study explores the relationship between the unemployment rate in the United States and South Africa’s stock prices from the beginning of 2013 to the last day 2017. The objective of this paper is to examine the impact of the US unemployment rate announcement on the South African financial market. Results of Impulse Response analysis show that there is a very minimal impact from the US unemployment announcement to South Africa’s stock prices which disappears within two days of the announcement. In addition, the Johannesburg stock exchange index marginally responds to own shocks, which marginally fades away within two days. These findings imply that the changes in the US employment policies have a direct ripple effect on the South African macroeconomic environment, its investing public sentiments and corporate confidence on the future prospects of businesses.

scholarly journals Probabilistic seismic response analysis of coastal highway bridges under scour and liquefaction conditions: does the hydrodynamic effect matter?

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Xiaowei Wang ◽  
Yutao Pang ◽  
Aijun Ye
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Highway Bridges ◽  
Element Model ◽  
Response Analysis ◽  
Hydrodynamic Effect ◽  
Strong Earthquakes ◽  
Influence Of Water ◽  
Scour Hazard ◽  
Ground Motion Records

AbstractCoastal highway bridges are usually supported by pile foundations that are submerged in water and embedded into saturated soils. Such sites have been reported susceptible to scour hazard and probably liquefied under strong earthquakes. Existing studies on seismic response analyses of such bridges often ignore the influence of water-induced hydrodynamic effect. This study assesses quantitative impacts of the hydrodynamic effect on seismic responses of coastal highway bridges under scour and liquefaction potential in a probabilistic manner. A coupled soil-bridge finite element model that represents typical coastal highway bridges is excited by two sets of ground motion records that represent two seismic design levels (i.e., low versus high in terms of 10%-50 years versus 2%-50 years). Modeled by the added mass method, the hydrodynamic effect on responses of bridge key components including the bearing deformation, column curvature, and pile curvature is systematically quantified for scenarios with and without liquefaction across different scour depths. It is found that the influence of hydrodynamic effect becomes more noticeable with the increase of scour depths. Nevertheless, it has minor influence on the bearing deformation and column curvature (i.e., percentage changes of the responses are within 5%), regardless of the liquefiable or nonliquefiable scenario under the low or high seismic design level. As for the pile curvature, the hydrodynamic effect under the low seismic design level may remarkably increase the response by as large as 15%–20%, whereas under the high seismic design level, it has ignorable influence on the pile curvature.

Evolution of seismic design codes of highway bridges in Chile

2021 ◽  
pp. 875529302098801
Author(s):  
José Wilches ◽  
Hernán Santa Maria ◽  
Roberto Leon ◽  
Rafael Riddell ◽  
Matías Hube ◽  
...  
Keyword(s):  
Seismic Design ◽  
Failure Modes ◽  
Highway Bridges ◽  
Design Codes ◽  
Seismic Codes ◽  
Analysis And Design ◽  
Residual Displacements ◽  
Shear Keys ◽  
Maule Earthquake ◽  
2010 Maule Earthquake

Chile, as a country with a long history of strong seismicity, has a record of both a constant upgrading of its seismic design codes and structural systems, particularly for bridges, as a result of major earthquakes. Recent earthquakes in Chile have produced extensive damage to highway bridges, such as deck collapses, large transverse residual displacements, yielding and failure of shear keys, and unseating of the main girders, demonstrating that bridges are highly vulnerable structures. Much of this damage can be attributed to construction problems and poor detailing guidelines in design codes. After the 2010 Maule earthquake, new structural design criteria were incorporated for the seismic design of bridges in Chile. The most significant change was that a site coefficient was included for the estimation of the seismic design forces in the shear keys, seismic bars, and diaphragms. This article first traces the historical development of earthquakes and construction systems in Chile to provide a context for the evolution of Chilean seismic codes. It then describes the seismic performance of highway bridges during the 2010 Maule earthquake, including the description of the main failure modes observed in bridges. Finally, this article provides a comparison of the Chilean bridge seismic code against the Japanese and United States codes, considering that these codes have a great influence on the seismic codes for Chilean bridges. The article demonstrates that bridge design and construction practices in Chile have evolved substantially in their requirements for the analysis and design of structural elements, such as in the definition of the seismic hazard to be considered, tending toward more conservative approaches in an effort to improve structural performance and reliability for Chilean bridges.

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