Seismic analysis of structures subjected to spatially varying. Seismic analysis of structures subjected to spatially. Approximate modal response spectrum method of analysis. A simplified multisupport response spectrum method springerlink. The timehistory responses of a set of fixedend arches rigid or medium rigid structures are calculated,according to two sets of multipoint records of medi um. The earthquake engineering online archive nisee elibrary. Jun 17, 2019 the response spectrum method rsm has been incorporated into many codes for seismic design of aboveground structures since 1950s. May 22, 2017 once the displacement timehistory record is obtained from an acceleration record, ground motion may be applied to specific support restraints through manual multi support excitation, described as follows. In this paper, the rsm is developed for the seismic analysis of the underground structures including ssi. An efficient response spectrum analysis of structures under multi. The second source depends directly upon the ratio of the longest structural dimension to the shortest significant wavelength.
Because of the limitations of the tests data, the principles of seismic performance of multi span cablestayed bridges under multi support excitations will not be discussed in detail here. Paper open access numerical simulation on seismic behavior of. This paper proposes a response spectrum method rsm for evaluating nonlinear. The seismic spectral response of structures can be expressed based on several correlation coefficients and the time consumption can be greatly reduced if the coefficients are expressed in closedform. Seismic response study on a multispan cablestayed bridge.
Because of the limitations of the tests data, the principles of seismic performance of multispan cablestayed bridges under multisupport excitations will not be discussed in detail here. Pdf loaddependent ritz ldr vectors are used in conjunction with. The support motions are taken to be a vector of jointly stationary gaussian random 1. Seismic response and design method of single large span. A new response spectrum method is developed for seismic analysis of linear multi degreeoffreedom. Seismic response analysis of longspan structures under multi support excitations has been the subject of extensive investigations during the past decades. An efficient approach for seismic analysis of multisupport.
Seismic design for steel trussed arch to multisupport. Error study of displacement model for seismic analysis of. Response spectrum method for multisupport seismic excitations, earthquake. Spatial variation of earthquake ground motion is an important phenomenon that cannot be ignored in the design and safety of strategic structures. A significant change in the correlation of the motions between the two supports is due to the combined effects of wave passage, coherency loss and local soil conditions. As the maximum difference between the spectral analysis and psdf based response spectrum method is 15%, the difference between the spectral analysis and response spectrum method is 125%.
Wang, implementation of the practical pseudo excitation method for multisupport seismic response analysis in general fem software, journal of earthquake engineering and engineering vibration, vol. The advantage of the method is that the linear peak seismic response of the arch to multisupport excitations can be obtained as conveniently as the conventional response spectrum method does. A response spectrum method for multiplesupport seismic. Based on the random vibration theory, a response spectrum method is developed for seismic response analysis of linear, multidegreeoffreedom structures under multisupport excitations is developed. Response spectrum method for multisupport seismic excitations. Effect of multi support excitation on seismic response of. Sensitivity analysis of a seismic risk scenario using. Pdf response spectrum method in seismic analysis and. Hazard model, described via a mixed technique combining greens function and stochastic methods, is used to simulate freefield seismic records. Numerical simulation on seismic behavior of a bridge under multisupport excitations considering site effect to cite this article. Generation of spatially varying ground motion based on. Analysis of cablestayed bridges under multicomponent random ground motion by response spectrum method. Seismic response of longspan tripletower suspension.
An efficient calculation method for seismic spectral analysis. Ucbeerc9109 a preliminary study on energy dissipating claddingtoframe connections, cohen, julie mark. Influence of incoherence and wave passage effects on seismic performances of long immersed tunnel. Active tendon control systems for structures subjected to. A fast simulation method was developed in the current study. Understanding these influences is important for seismic design. As a special case of multitower suspension bridge, two longspan tripletower suspension bridges have been constructed in china and the seismic random response of tripletower suspension bridges is.
A gridbased method to represent the covariance structure. Influence of apparent wave velocity on seismic performance of. The response spectrum method causes much larger bending moments than those of the former two methods. A new response spectrum method is developed for seismic analysis of linear multi. Dynamic responses of bridges under effects of asynchronous. For example, several response spectrum method have been developed by different researchers to calculate the seismic response of. Response spectrum method for multi support seismic excitations j. Therefore, the structural response under nonstationary seismic excitation requires further study. Based on the random vibration theory, a response spectrum method is developed for seismic response analysis of linear, multi degreeoffreedom structures under multi support excitations is developed. Its advantages are that the formulation considering the modal response variances and crosscovariances is more efficient in calculation than the conventional formulation, and the. Variations of the ground motion due to wave passage, loss of coherency with distance and variation of local soil conditions are included. Using the acceleration response spectrum, an equivalent static load is derived which will provide the same maximum response as that obtained in each. This article aims at studying the seismic response rules and design method of single large span structures to spatially varying ground motions. Structures, such as bridges, pipelines which are supported at multiple places, will be subjected to differential excitation.
Pseudo excitation method and some recent developments. A significant change in the correlation of the motions between the two s. However, almost all the procedures for the evaluation of variation assumed that the random field is homogeneous in space. This load pattern should apply unit values of joint displacement in the direction of applied acceleration. Summary a new response spectrum method is developed for seismic analysis of linear multidegreeoffreedom,multiply supported structures subjected to spatially varying ground motions. In this paper,the general analytic solutions of the responses of the fixed end arch,2hinged arch and 3hinged arch to the multisupport seismic ex citations are derived,considering the arches as the nonorthogonal barsystems. Aim at this problem, the paper considers interaction of surrounding rocktunnel liningwater system and considers traveling wave effect.
Summary a new response spectrum method is developed for seismic analysis of linear multidegreeoffreedom. Numerical simulation on seismic behavior of a bridge under multi support excitations considering site effect to cite this article. A corrected earthquake power spectral density model is first proposed and applied to the following solution process. Multiplesupport seismic response of bosporus suspension bridge. A simplified multisupport response spectrum method request pdf. Response spectrum method for multisupport seismic excitation, earthquake eng. A spectralrepresentation based algorithm is used to generate response spectrum compatible time histories at different support points of the dam. An efficient approach for seismic analysis of multi support structures equipped with coupled dampers using spectral moments instead of crosscorrelation coefficients.
The seismic spectral computation of structures is timeconsuming under multiple support excitations. The good agreement of results between the timehistory method and the average response spectrum method shows the validity of the latter method. Spectrum method for multisupport seismic excitations, earthquake. The first component is the pseudostatic response caused by the inconsistent motions of the structural supports, and the second is the structural dynamic response to ground. Multiple support excitations of elastic multispan beams are studied. For largescale waterconveying tunnel, the spatial variation characteristics of earthquake excitation, namely, multipoint input has great effects on seismic response of the waterconveying tunnel. Analysis method for the response of structures subjected to.
New developments in the response spectrum method have led to calculations in seismic stresses that are more accurate, and usually lower, than those obtained by conventional methods. Influence of apparent wave velocity on seismic performance. Manual multisupport excitation technical knowledge base. Based on the pseudoexcitation algorithm, a response spectrum method for multisupport seismic excitations is presented, where, the structural response consist of three components, ie. This load pattern should apply unit values of joint displacement in the direction of applied. Sep 10, 20 the response spectrum method of analysis is developed using the following steps. In this article, the critical issues concerning the. Seismic analysis of longspan cablestayed bridges by an. Variations of the ground motion due to wave passage, loss of coherency with distance. As one of the main characteristics of seismic waves, apparent wave velocity has great influence on seismic responses of longspan suspension bridges. Earthquake engineering and structural dynamics, 1992, 218. Seismic response analysis for tunnel conveying water under. Seismic response of longspan tripletower suspension bridge. Analysis of seismic response cannot be based on the single assumption that freefield ground motions are spatially uniform.
This paper provides a very efficient, integrated framework for seismic analyses of longspan cablestayed bridges. Datta department of civil engineering, iit delhi response spectrum method of analysis 0 5 10 15 20 25 30 0. Neuenhofer 1992 also proposed a concept of random vibrationbased response spectrum method for. Comparison of some code provisions prescribed by different earthquake codes. Response spectrum method for multisupport seismic excitations j. It is obvious that reality does not fully conform to the assumption. A method for nonstationary earthquake responses of suspension bridges was presented by multiple support excitations 5. Response spectrum method for multi support seismic excitations.
Ab stands for the modulus of the coherence function. Soyluk, comparison of random vibration methods for multi support seismic. The efficiency comes from the dramatic reduction in formation time and the degrees of freedom dof associated with the structure, using the integrated finite strip method ifsm along with the application of a very robust and efficient time history method thm using the newmark. Mar 03, 2016 this paper provides a very efficient, integrated framework for seismic analyses of longspan cablestayed bridges. The spectral method of seismic analysis is based on the formulation of the dynamic response transient by modal recombination presented in the documents methods of ritz in linear and nonlinear dynamics r5. Response spectrum method for seismic soilstructure. How to investigate the inhomogeneous feature of ground. Cascaded analysis of secondary systems using response spectrum method. Influence of incoherence and wave passage effects on. Spatial seismic excitations and response spectra zbigniew zembaty opole university of technology 45271 opole ul. The response spectrum method rsm has been incorporated into many codes for seismic design of aboveground structures since 1950s. The response spectrum in the case of multisupport excitations then. However, no rsm is presented in details for the seismic design of underground structures due to the complexity of seismic soilstructure interaction ssi. Based on the staticg method which did not account for differ ences in.
The new response spectrum method is shown to offer a simple and viable alternative for seismic analysis of multiply supported structures subjected to spatially varying ground motions. Response spectrum method in seismic analysis and design of structures article pdf available in bulletin of the new zealand society for earthquake engineering 263. Provides comprehensive coverage, from seismology to seismic control contains useful empirical equations often required in the seismic analysis of structures outlines explicit steps for seismic analysis of mdof systems with multi support excitations works through solved problems to illustrate different concepts makes use of matlab, sap2000 and. With this book, readers will gain proficiencies in the following. Datta while numerous books have been written on earthquakes, earthquake resistance design, and seismic analysis and design of structures, none have been tailored for advanced students and practitioners, and those who would like to have most of the important aspects of seismic analysis in one place. A formulation is developed for analyzing the dynamic response of multisupport structures with coupled nonclassical damping using spectral moments instead of the frequently used crosscorrelation coefficients. In this paper, the rsm is developed for the seismic analysis of the underground structures. Response spectrum method of analysis mechanical engineering.
Response spectrum method of analysis seismic analysis of. A simplified multisupport response spectrum method is presented. A response spectrum method is proposed for the seismic. The method is particularly effective when a comprehensive understanding of the spatial variability effect. Concept of equivalent lateral force and response spectrum method of analysis.
Analysis method for the response of structures subjected. An efficient approach for seismic analysis of multi. The structural response is a sum of two components of a structure with a first natural period less than 2 s. Response spectrum method of analysis with simplified.
Multitower suspension bridge is of different style compared to the traditional suspension bridge with two towers, and consequently the dissimilarity of static and dynamic behaviors is distinct. The frequently used dynamic analysis method is adopted in this. The response spectrum method of analysis is developed using the following steps. Global parametric sensitivity analysis of a complete seismic risk scenario is performed by means of the response surface method based on sparse chebyshev polynomial expansion. Pdf multiplesupport response spectrum analysis using load. Once the displacement timehistory record is obtained from an acceleration record, ground motion may be applied to specific support restraints through manual multisupport excitation, described as follows at joints of interest, define a load pattern.
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