scholarly journals The Characteristics of Seismic Response on Hard Interlayer Sites

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jie Su ◽  
Zhenghua Zhou ◽  
You Zhou ◽  
Xiaojun Li ◽  
Qing Dong ◽  
...  
Keyword(s):  
Seismic Response ◽  
Nonlinear Effect ◽  
Response Spectrum ◽  
Equivalent Linearization ◽  
Interlayer Thickness ◽  
Peak Acceleration ◽  
Seismic Responses ◽  
Acceleration Response ◽  
Short Period ◽  
Acceleration Response Spectrum

Based on the engineering geological data of a nuclear power plant site, nine engineering geological profiles were created with hard interlayers of different thicknesses. The equivalent linearization method of seismic motion segment-input used for one-dimensional nonlinear seismic response analysis was applied to study the effect of the interlayer thickness on the peak acceleration and the acceleration response spectra of the site seismic response. The results showed that there was an obvious influence of hard interlayer thickness on site seismic responses. With the increase of hard interlayer thickness, the site nonlinear effect on seismic responses decreased. Under the same thickness of the hard interlayer, the nonlinear effect of the site was strengthened with the higher input peak acceleration. In addition, the short-period acceleration response spectrum was found to be significantly influenced by the hard interlayer and showed that the longer the period, the less influence of the hard interlayer on the acceleration response spectrum coordinates. Moreover, the influenced frequency band was wider with the increase in the thickness of hard interlayer.

Analysis of Different Seismic Response between Low and High Stories of Buildings

2012 ◽  
Vol 166-169 ◽  
pp. 2115-2119
Author(s):  
Kun Xia ◽  
Ling Xin Zhang ◽  
Jie Ping Liu ◽  
Lin Dong
Keyword(s):  
Seismic Response ◽  
Response Spectrum ◽  
Displacement Velocity ◽  
Response Analysis ◽  
Acceleration Response ◽  
Seismic Response Analysis ◽  
Time Histories ◽  
Acceleration Response Spectrum

In general, the higher story of the building, the stronger effects on humans and objects. In this paper, seismic response analysis for two buildings is carried out. The time histories of displacement, velocity, acceleration and acceleration response spectrum of each floor are obtained. By analyzing these results, the phenomenon of "the higher story of the building, the stronger effects on humans and objects" is demonstrated. And reasons of this phenomenon are preliminary analyzed.

The Comparative Analysis on Calculation Methods of Vertical Seismic Response to Suspended-Dome Structure

2013 ◽  
Vol 351-352 ◽  
pp. 849-853
Author(s):  
Lan Chen ◽  
De Long Lu ◽  
Xiao Gang Yin
Keyword(s):  
Response Spectrum ◽  
Time History ◽  
Seismic Effect ◽  
Time History Analysis ◽  
Vertical Acceleration ◽  
Analysis Method ◽  
Calculation Methods ◽  
Acceleration Response ◽  
History Analysis ◽  
Acceleration Response Spectrum

Based on the vertical seismic information, the vertical seismic response spectrum was calculated by Matlab Lsim function. The seismic effect of Kiewitt-Lamella suspended-dome was measured by dynamic to static ratio. According to the EL-Centro seismic wave, it analyzed and compared the dynamic to static ratios which were calculated by the following four vertical seismic calculation methods respectively: the simplified method of specification, the mode-superposition response spectrum methods based on the horizontal earthquake affecting coefficients and the vertical acceleration response spectrum respectively, and the time history analysis method. Analysis shows that: For the seismic effect, the time history analysis method is larger than the other three methods, and the method based on the vertical acceleration response spectrum is closer to the time history analysis method. Owing to large difference of the four methods for seismic effect, various methods should be adopted to ensure the safety of vertical seismic design.

Response Spectrum Analysis Method of Footbridge Lateral Vibration under Man-Bridge Interaction

2013 ◽  
Vol 838-841 ◽  
pp. 1165-1169
Author(s):  
Yu Nan ◽  
Zhi Gang Song ◽  
Shi Jiao
Keyword(s):  
Design Method ◽  
Response Spectrum ◽  
Damping Ratio ◽  
Interaction Model ◽  
Dynamic Interaction ◽  
Stride Frequency ◽  
Social Force ◽  
Acceleration Response ◽  
Weighting Method ◽  
Acceleration Response Spectrum

Based on the uniform experimental design method and combining with the additional lateral pedestrian role derived from social force, this paper establishes human-bridge dynamic interaction model and calculates dynamic response of simply supported structures with different span, damping ratio, walking stride frequency and other parameters under the man-bridge dynamic interaction. The acceleration response spectrum is obtained by FFT transform of acceleration response. Then RMS-acceleration response spectrum is calculated in accordance with ISO overall frequency weighting method and the response spectrum envelope formula is fitted by parametric analysis.

scholarly journals Study on the influence of seafloor soft soil layer on seismic ground motion

2020 ◽  
Author(s):  
Jingyan Lan ◽  
Juan Liu ◽  
Xing Song
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Sea Water ◽  
Response Spectrum ◽  
Soft Soil ◽  
Free Field ◽  
Soil Layer ◽  
Response Analysis ◽  
Peak Acceleration ◽  
Seismic Response Analysis

Abstract. In the complex medium system of sea area, the overlying sea water and the surface soft soil have a significant impact on the seafloor ground motion, which brings great seismic risk to the safety of offshore engineering structures. In this paper, four sets of typical free field models are constructed and established, which are land model, land model with surface soft soil, sea model and sea model with surface soft soil. The dynamic finite difference method is used to carry out two-dimensional seismic response analysis of typical free field based on the input forms about P and SV wave. By comparing the seismic response analysis results of four groups of calculation models, the effects of overlying seawater and soft soil on peak acceleration and acceleration response spectrum are studied. The results show that when SV wave is input, the peak acceleration and response spectrum of the surface of soft soil on the surface and the seabed surface can be amplified, while the overlying sea water can significantly reduce the ground motion. When P wave is used, the effect of overlying seawater and soft soil on peak acceleration and response spectrum of surface and seabed can be ignored. The peak acceleration decreases first and then increases from the bottom to the surface, and the difference of peak acceleration calculated by four free field models is not obvious. The results show that the overlying sea water and the surface soft soil layer have little effect on the peak acceleration of ground motion below the surface.

scholarly journals ACCELERATION RESPONSE SPECTRUM AND EFFECTIVE DURATION OF LEBAK EARTHQUAKE JANUARY 23, 2018 IN JAKARTA REGION

2019 ◽  
Vol 4 (1) ◽  
pp. 21-30
Author(s):  
Muhammad Fikri Hayqal Hiola ◽  
Bambang Sunardi
Keyword(s):  
Response Spectrum ◽  
Capital City ◽  
Acceleration Response ◽  
South Indian ◽  
Significant Acceleration ◽  
Acceleration Data ◽  
Statistical Analysis Method ◽  
Acceleration Response Spectrum ◽  
Motion Characteristics ◽  
Very High

Jakarta is the capital city of Indonesia with a very high population density low to the upper distribution of buildings which causes many areas of Jakarta to have a high vulnerability to natural disasters, one of which is an earthquake. One of the earthquakes felt this year was Lebak Banten Earthquake January 23, 2018, with a magnitude 6.1 at 13.34 local time. The depth of the earthquake was 61 Km at -7.09o S - 106.03o E, in the South Indian Ocean of Java Island. The epicenter was 43 km from Cilangkahan Village, Malingping Sub-district, Lebak District, Banten. We analyze the ground motion characteristics in the Jakarta area using 3 component acceleration data at Jakarta City Hall Office (JAKO) and Tanjung Priok Maritime Station (JATA) with dynamic statistical analysis method. The effective duration and earthquake response spectrum are determined using the acceleration data. In this study, the active period of the earthquake was calculated using the Trifunac and Brady method. The results of the analysis show that the most significant acceleration spectrum at JAKO station is found in component E of 0.07742 g in the period of 0.54 s while for the most significant acceleration spectrum JATA station found in component N of 0.04572 g in the period of 0.58 s. The effective duration obtained at JAKO stations was 56.76 s and JATA station 63.47 s. These results indicate that in the case of the Lebak earthquake, the further region from the epicenter of the earthquake has an effective duration which is relatively longer.

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.

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.

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