A Suggestion to the Vertical Earthquake Action Stipulated in Seismic Design Specification

2014 ◽  
Vol 580-583 ◽  
pp. 1750-1754
Author(s):  
Hai Ming Liu ◽  
Xia Xin Tao ◽  
Jin Yuan Wang
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Maximum Amplitude ◽  
Spectral Ratio ◽  
Design Specification ◽  
Design Response Spectrum ◽  
Site Category ◽  
Earthquake Action ◽  
Acceleration Response Spectrum ◽  
Vertical Action

In order to further regulate the vertical earthquake action in seismic design specification, to overcome the unreasonable and inconvenient flaws in certain conditions by using vertical to horizontal spectra ratio function, the feasibility of stipulating vertical design response spectrum with the same way of horizontal one is deal with in this paper. 1513 sets of three component records during 64 earthquakes from NGA-west1 database are selected and grouped by magnitude, distance and site conditions. Average acceleration response spectrum of each group is generalized to get the corresponding mean maximum amplitude and effective peak acceleration EPA. Furthermore, some groups with EPA in an interval are merged into one. Once again, the parameters, such as maximum amplitude and characteristic periods of each final grouping are acquired by the same way. The former is divided by the corresponding horizontal value for site category, to obtain the site coefficient for vertical action. Finally a preliminary suggestion of vertical site coefficient and characteristic period are presented. Comparison of observed data with results from the new suggestion and those from spectral ratio shows that the improvement of this study is obvious.

A Comparative Study of Seismic Performance Defined by Chinese Code and Eurocode8 on Seismic Design of Bridges

2011 ◽  
Vol 90-93 ◽  
pp. 3108-3116
Author(s):  
Ben Yan Lu ◽  
Gang Wang
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Highway Bridges ◽  
Lessons Learned ◽  
Performance Criteria ◽  
Existing Problems ◽  
Performance Based Seismic Design ◽  
Earthquake Action ◽  
Ground Types ◽  
Current Code

Earthquake codes have been revised and updated in recent years. The issue and implementation of the guidelines for seismic design of bridges have attracted interests and attentions of many researchs at home and abroad. The most important aspect of the code rests on its main approach incorporating “performance-based seismic design”. The main purpose of this study is to investigate the differences caused by the use of guidelines for seismic design of highway bridges and Eurocode8 for bridges in performance criteria, seismic design categories, ground types, response spectrum, earthquake action and detailing of ductile piers. The differences in expressions and some important points for performance criteria, seismic design categories, ground types, response spectrum, earthquake action and detailing of ductile piers by codes are briefly illustrated in tables and figures. Based on the lessons learned from significant earthquakes in the last few years, the existing problems of the current code are pointed, and the trends of future study are discussed.

Effects of Site Classification on Platform Value of Response Spectrum

2011 ◽  
Vol 378-379 ◽  
pp. 306-309
Author(s):  
Ping Li ◽  
Jing Shan Bo ◽  
Xiao Yun Guo ◽  
You Wei Sun ◽  
Yu Dong Zhang
Keyword(s):  
Ground Motion ◽  
Seismic Design ◽  
Wave Motion ◽  
Response Spectrum ◽  
Equivalent Linearization ◽  
Earthquake Response ◽  
Response Analysis ◽  
Site Classification ◽  
Earthquake Motion ◽  
Design Response Spectrum

Regarding the design response spectrum in the code for seismic design of buildings as target spectra，the 28 acceleration histories are formed artificially．They are used as the inputs ground motion in earthquake response analysis．Four site classifications profiles were selected or constructed from practical site profiles．With the use of 1-D equivalent linearization wave motion method that is wildly used at present in site seismic response analysis, the platform values of surface response spectrum for different profiles under different ground motion inputs were calculated．Different platform values of the response spectrum and relational expression which is seven input earthquake motion intensity and site classifications have been given by statistical analysis.

Comparison and Research on Seismic Performance between Guidelines for Seismic Design of Highway Bridges and Eurocode 8 for Seismic Design of Bridges

2010 ◽  
Vol 163-167 ◽  
pp. 4395-4400
Author(s):  
Ben Yan Lu ◽  
Bo Quan Liu ◽  
Ming Liu ◽  
Guo Hua Xing
Keyword(s):  
Seismic Design ◽  
Future Study ◽  
Response Spectrum ◽  
Highway Bridges ◽  
Lessons Learned ◽  
Performance Criteria ◽  
Eurocode 8 ◽  
Existing Problems ◽  
Earthquake Action ◽  
Current Code

Earthquake codes have been revised and updated in recent years. The issue and implementation of the guidelines for seismic design of bridges have attracted interests and attentions of many researchs at home and abroad. In this paper, it is compared that the provisions about performance criteria, seismic design categories, response spectrum and earthquake action between guidelines for seismic design of highway bridges and Eurocode 8 for bridges. The main purpose of this study is to investigate the differences caused by the two codes in performance criteria, seismic design categories, response spectrum and earthquake action. The results indicate that it is similar in performance criteria, seismic design categories and response spectrum between guidelines for seismic design of highway bridges and Eurocode 8 for bridges. Based on the lessons learned from significant earthquakes in the last few years, the existing problems of the current code are pointed, and the trends of future study are discussed.

Smooth Acceleration Spectra for Pulse-Like Ground Motions

2020 ◽  
Vol 110 (6) ◽  
pp. 2755-2765
Author(s):  
Cuihua Li ◽  
Guofeng Xue ◽  
Zhanxuan Zuo
Keyword(s):  
Seismic Design ◽  
Amplification Factor ◽  
Response Spectrum ◽  
Ground Motions ◽  
Response Spectra ◽  
Acceleration Response ◽  
Constant Acceleration ◽  
Step Procedure ◽  
Acceleration Response Spectrum ◽  
Smooth Acceleration

ABSTRACT Idealization of acceleration response spectra is the basis for construction of target spectra for seismic design and assessment of structures. The adequacy of current methods to reasonably idealize (or smooth) the acceleration spectra of pulse-like and nonpulse-like ground motions is examined in this study. The influence of separated pulses on different regions of acceleration response spectrum is first investigated using wavelet transform. One representative method is selected as the benchmark to examine the effectiveness of the Newmark–Hall-based methods to smooth the acceleration spectra of pulse-like and nonpulse-like ground motions. Presented are some important insights into why the plateau (or amplification factor) associated with the constant-acceleration branch may be underestimated and the ending cutoff period Tg be overestimated by Newmark–Hall-based methods. This study highlights the intrinsic characteristics and the importance of the constant-acceleration branch, based on which a two-step procedure is proposed to idealize the acceleration spectra. The results show that the proposed methodology can accurately identify the constant-acceleration branch regardless of the influence of pulses on the descending branch of acceleration spectra.

A Comparative Study of Design Base Shear for RC Buildings in Selected Seismic Design Codes

2012 ◽  
Vol 28 (3) ◽  
pp. 1047-1070 ◽  
Author(s):  
Vijay Namdev Khose ◽  
Yogendra Singh ◽  
Dominik H. Lang
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Cumulative Effect ◽  
Building Design ◽  
Site Classification ◽  
Eurocode 8 ◽  
Design Codes ◽  
Base Shear ◽  
Rc Buildings ◽  
Design Response Spectrum

Modern seismic building design codes tend to converge on issues of design methodology and the state-of-the-art. However, significant differences exist in basic provisions of various codes. This paper compares important provisions related to the seismic design of RC buildings in some of the major national seismic building codes viz. ASCE 7, Eurocode 8, NZS 1170.5, and IS 1893. Code provisions regarding the specification of hazard, site classification, design response spectrum, ductility classification, response reduction factors, and minimum design base shear are compared and their cumulative effect on design base shear is studied. The objective component of overstrength contributed by the material and load factors is considered to normalize the design base shear. It is observed that every code has merit over the other codes in some aspect. The presented discussion highlights the major areas of differences which need attention in the process of harmonization of different codes of the world.

Bi-Directional Pseudo-Acceleration Response Spectra

2016 ◽  
Vol 10 (04) ◽  
pp. 1650007
Author(s):  
Anat Ruangrassamee ◽  
Chitti Palasri ◽  
Panitan Lukkunaprasit
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Ground Motions ◽  
Strong Motion ◽  
Response Spectra ◽  
Acceleration Response ◽  
Acceleration Response Spectra ◽  
Acceleration Response Spectrum ◽  
Two Degree Of Freedom ◽  
Ratio Response

In seismic design, excitations are usually considered separately in two perpendicular directions of structures. In fact, the two components of ground motions occur simultaneously. This paper clarifies the effects of bi-directional excitations on structures and proposes the response spectra called “bi-directional pseudo-acceleration response spectra”. A simplified analytical model of a two-degree-of-freedom system was employed. The effect of directivity of ground motions was taken into account by applying strong motion records in all directions. The analytical results were presented in the form of the acceleration ratio response spectrum defined as the bi-directional pseudo-acceleration response spectrum normalized by a pseudo-acceleration response spectrum.

A Semi-Automated Procedure for Selecting and Scaling Recorded Earthquake Motions for Dynamic Analysis

2008 ◽  
Vol 24 (4) ◽  
pp. 911-932 ◽  
Author(s):  
Albert Kottke ◽  
Ellen M. Rathje
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Ground Motions ◽  
Acceleration Response ◽  
Analysis Process ◽  
Target Spectrum ◽  
Acceleration Response Spectrum ◽  
Individual Scale ◽  
The Individual ◽  
Selection Of

Suites of earthquake ground motions play an important role in the seismic design and analysis process. A semi-automated procedure is described that selects and scales ground motions to fit a target acceleration response spectrum, while at the same time the procedure controls the variability within the ground motion suite. The basic methodology selects motions based on matching the target spectral shape, and then fits the amplitude and standard deviation of the target by adjusting the individual scale factors for the motions. The selection of motions from a larger catalog of motions is performed through either a rigorous method that tries each possible suite of motions or an iterative approach that considers a smaller set of potential suites in an effort to find suites that provide an acceptable fit to the target spectrum. Guidelines are provided regarding the application of the developed procedures, and example applications are described.

Determination of Modification Factor R for Seismic Design of Pressure Vessels Using ASME and Eurocodes

2005 ◽  
Author(s):  
N. Kokavesis ◽  
Ch. Botsis
Keyword(s):  
Seismic Design ◽  
Pressure Vessel ◽  
Structural Design ◽  
Response Spectrum ◽  
Pressure Vessels ◽  
Design Codes ◽  
Allowable Stress ◽  
Design Response Spectrum ◽  
Modification Factor ◽  
External Loads

The design of pressurized equipment such as columns, towers and reactors, heaters subjected to external loads is important from a safety point of view. Pressure vessel design codes provide guidelines for the combination of membrane stresses due to external loads and hoop stress. Customarily the seismic loads imposed by pressure vessel design codes are functions of allowable stress. The factor R is a modification factor of the design response spectrum. Its numerical value is based the capacity of a structural system to resist seismic actions in the nonlinear range. It generally reduces the seismic design forces to be smaller than those corresponding to a linear elastic response. The Uniform Building Code (UBC) has been used extensively for the seismic design of pressure vessels. With the advent of EUROCODES [2], the values proposed by UBC for factor R (usually 3 or 4) are not automatically accepted by local authorities. The pressure vessel mechanical designer must select a factor R that satisfies both the requirements of the pressure vessel code and the structural design code (local code) where the vessel is installed. This problem has also been acknowledged by several collogues in the past PVP conferences. In this paper the factor R is examined using ASME [10] codes and the guidelines provided by EUROCODES. A common basis for the selection of the factor R that satisfies both allowable stress design philosophies and structural design codes is established.

Theoretical Analysis of Seismic Response for Marine Drilling Risers

2013 ◽  
Vol 423-426 ◽  
pp. 1531-1536 ◽  
Author(s):  
Jun Qiang Li ◽  
Yi Fan Li ◽  
Yong Peng
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Bending Moment ◽  
Continuous System ◽  
Oil Industry ◽  
Offshore Drilling ◽  
Earthquake Force ◽  
Drilling Engineering ◽  
Internal Forces ◽  
Earthquake Action

With the continuous development of the marine oil industry, risers have become necessary equipment in offshore drilling engineering. On the basis of mode-superposition response spectrum method which is used commonly in anti-seismic design, the seismic responses of the marine drilling riser is analyzed on the theoretical and the related anti-seismic calculation formulas of the discrete system are promoted to the continuous system. The earthquake force and the resultant internal forces when the earthquake happening are analyzed and calculated. The calculation formulas of shear force and bending moment for each cross section of a riser under the earthquake action are deduced, which can offers some theoretical reference for riser engineering design when considering earthquake action.

Comparison of Base Shear Force Method in the Seismic Design Codes of China, America and Europe

2012 ◽  
Vol 166-169 ◽  
pp. 2345-2352
Author(s):  
Zhi Nan Jiang ◽  
Zhong Hai Zhao
Keyword(s):  
Seismic Design ◽  
Shear Force ◽  
Response Spectrum ◽  
Base Shear ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Force Method ◽  
Frame Building ◽  
Design Response Spectrum ◽  
Seismic Forces

Seismic design response spectrum and earthquake action in Chinese new seismic code (GB50011-2010), ASCE/SEI7-05 and Eurcode8 were gathered in this paper. Using base shear force method of each code, the authors computed the horizontal seismic forces of a three-story reinforced concrete frame building under the same conditions. The results show that the three static methods roughly approach, while the different parameters lead to discrepancies in calculated values.

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