General Laws of Dynamic Responses of the High Slope Construction under Earthquake

2014 ◽  
Vol 1065-1069 ◽  
pp. 1412-1417
Author(s):  
Yong Li ◽  
Ren He Jin

Based on stochastic seismic response and time-history seismic response analysis,Dynamic response laws of the high slope constructions by three real seismic waves and a synthetic seismic wave were studied using finite - element method, discussing the differentiation and relation between the high slope constructions and ground constructions. The results show that the dynamic response on high slope constructions are less intensive than ground constructions due to delaying effect of high slope soil acts on the structure, but its internal force stronger than ground constructions as the pile in high slope constructions are anti-sliding and bearing. Results are conducive to the seismic design of high slope constructions.

2011 ◽  
Vol 90-93 ◽  
pp. 2108-2111
Author(s):  
Lin Jie Chen ◽  
Bo Liang ◽  
Zhi Yong Wang

Based on soil-structure interaction model, the seismic dynamic response of tunnel in karst areas were performed by using viscous-spring artificial boundary and time history analysis method. In combination with the Menglian tunnel engineering on the Bao-Teng Highway in Yunnan, in different sizes and sites karst caves conditions, the dynamic responses of displacement and internal force on control points of the tunnel structure were obtained. The results show that comparatively large interal forces, under the high-intensity earthquake conditions, will appear on the side wall of the tunnel which through karst areas, less ones on arch crown and inverted arch parts, and the differential displacements of arch crown reach to the maximum. When the karst caves are located in the side of the tunnel, it make the seismic dynamic response get more large, which make the surrounding rock must be strengthened treatment. The results provide useful reference for the aseismatic design of tunnel.


2014 ◽  
Vol 912-914 ◽  
pp. 1534-1537
Author(s):  
Shao Bo Zhang ◽  
Ke Lun Wei ◽  
Bi Jian Xiao

This paper adopts large finite element software ANSYS to establish finite element model of twin-tower building with enlarged base, uses dynamic time history analysis method for seismic response calculation, compare and analyze the calculation results of twin-tower building with enlarged base under elastic boundary conditions and rigid boundary conditions. The results showe that dynamic response for model under elastic boundary conditions is larger than dynamic response for model under rigid boundary conditions, and elastic boundary conditions is more close to the actual situation.


Author(s):  
Satoru Kai ◽  
Tomoyoshi Watakabe ◽  
Naoaki Kaneko ◽  
Kunihiro Tochiki ◽  
Makoto Moriizumi ◽  
...  

The piping in a nuclear power plant is laid across multiple floors of a single building or two buildings, which are supported at many points. As the piping is excited by multiple-inputs from the supporting points during an earthquake, seismic response analysis by multiple excitations is needed to obtain the exact seismic response of the piping. However, few experiments involving such multiple excitation have been performed to verify the validity of multiple excitation analysis. Therefore, analysis of the seismic design of piping in Japan is performed by the enveloped Floor Response Spectrum (FRS), which covers all floor response spectra at all supporting points. The piping response estimated by enveloped FRS is conservative in most cases compared with the actual seismic response by multiple excitations. To perform rational seismic design and evaluation, it is important to investigate the seismic response by multiple excitations and to verify the validity of the analytical method by multiple excitation test. This paper reports the validation results of the multiple-excitation analysis of piping compared with the results of the multiple excitations shaking test using triple uni-axial shaking table and a 3-dimensional piping model (89.1mm diameter and 5.5mm thickness). Three directional moments from the analysis and the shaking test were compared on the validation. As the result, it is confirmed that the analysis by multiple time history excitation corresponds with the test result.


2012 ◽  
Vol 5 ◽  
pp. 183-188
Author(s):  
Lian Zhen Zhang ◽  
Tian Liang Chen

Self-anchored suspension bridge is widely used in Chinese City bridge engineering for the past few years. Because the anchorage system of main cable has been changed from anchorage blocks to the ends of the girder, its’ dynamic mechanics behavior is greatly distinguished with the traditional earth anchored suspension bridge. This paper studies the dynamic characteristics and seismic response of one large-span self-anchored suspension bridge which is located in China/Shenyang city. Using a spatial dynamic analysis finite element mode, the dynamic characteristics are calculated out. An artificial seismic wave is adopted as the ground motion input which is fitted with acceleration response spectrum according to the Chinese bridge anti-seismic design code. Time-integration method is used to get the seismic time-history response. Geometry nonlinear effect is considered during the time-history analysis. At last, the dynamic characteristics and the behavior of earthquake response of this type bridge structure are discussed clearly. The research results can be used as the reference of seismic response analysis and anti-seismic design for the same type of bridge.


2013 ◽  
Vol 353-356 ◽  
pp. 1846-1849
Author(s):  
Wen Jia Suo ◽  
Bing Zhu ◽  
Ning Zhao ◽  
Fan Wang ◽  
Sheng Tan Dou

To study the effects of seismic waves directions on bridges, the time history analytic method was used. Two bridge types, the railway continuous curved rigid frame bridge and the railway continuous straight rigid frame bridge, have been taken into account. Both the two same span bridges were used for comparative analysis about free vibration and seismic response feature, then some practical application conclusions were obtained. The longitudinal and transversal seismic waves produce the maximum reaction values. Besides, the pier bottom sections and the beam sections at the piers top are the critical sections in the bridges. In addition, this small radius curved bridge can be designed as the straight bridge in seismic design.


2011 ◽  
Vol 255-260 ◽  
pp. 1096-1101
Author(s):  
Qing Zhao

Taking an engineering design case about a city elevated curved box girders bridge, the dynamic calculating model of the curved box girders bridge is created by the finite element analysis program ANSYS. The analysis of curved box girders bridge with space seismic response are discussed, and a time history analysis is conducted for the curved box girders bridge subjected to the E1 Centro earthquake waves in two conditions.The internal force and the displacement time history response curve of the curved box girders bridge are obtained. The results indicate that the seismic response of curved box girders bridge with three-dimensional earthquake are bigger than two-dimensional, and consider the vertical seismic have considerable influence on the axial force of bridge piers, the internal force and displacement of box girders.


Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2062
Author(s):  
Zhenwei Lin ◽  
Chao Zhang ◽  
Jucan Dong ◽  
Jianliang Ou ◽  
Li Yu

The interaction between multiple loops and string cables complicates the dynamic response of triple square loops-string dome structures under seismic excitation. The internal connection between the multiple square loops-string cables and the grid beams was studies to provide a favorable reference for an anti-seismic structure. With a finite element model of the Fuzhou Strait Olympic Sports Center Gymnasium, established by SAP2000 software, the structural dynamic characteristic parameters were obtained first, and then this study adopted a time-history analysis method to study the internal force response of the cables and the roof grid beams of the multiple square loops-string dome (MSLSD) under three types of seismic array excitation. The influence of two factors, namely the seismic pulse and the near and far seismic fields, on the dynamic response of this structure was analyzed by three groups of different types of seismic excitation (PNF, NNF, PFF). As shown from the results, the first three-order vibration modes were torsional deformations caused by cables, the last five were mainly the overall roof plane vibration and antisymmetric vibration. Under the excitation of the three seismic arrays, the internal force responses of stay cables, square cables in the outer ring and the string cables were largest, while the maximum internal force response of the struts changed with the direction of seismic excitation. The largest internal force response of the roof grid beams occurred in local components such as BX3, BX7 and BY7, and the largest deformation of the beam nodes occurred in JX7, JX12 and JY4. In general, the seismic pulse and the near seismic field weakened the internal force response of the struts and cables but increased the internal force response and deformation of the dome beams, while the near and far seismic fields outweighed the seismic pulse. All the above provides an important reference for structural monitoring and seismic resistance.


2010 ◽  
Vol 163-167 ◽  
pp. 2167-2170
Author(s):  
Jing Ji ◽  
Tao Yang ◽  
Wen Fu Zhang ◽  
Liang Chang ◽  
Hai Yan Sui

Liquefied Natural Gas (LNG) tank is the important equipment in storage LNG. There has been a lot of research results abroad, but lack of seismic studies for the LNG tank in China. Domestic structural designers also have an urgent need for internal force and deformation law of LNG tanks under a variety of dynamic loads. This study focused on vibration characteristics and seismic response of a shell of LNG tank. Using ANSYS creat finite element model, obtain natural frequency and vibration mode etc. According to requirements of Chinese "code of building seismic design", analyze this shell of LNG tank of unidirectional horizontal seismic response under the action of selected three kinds of seismic waves. Time-history curves of LNG tank’s displacement, acceleration, stress distribution law under the action of selected three kinds of seismic waves are obtained.


2012 ◽  
Vol 503-504 ◽  
pp. 1104-1107
Author(s):  
Shi Qing Lu ◽  
Han Bin Xiao ◽  
Ping Deng

Earthquakes pose a threat to large-scale container cranes. Previous earthquakes damaged many container cranes, which had a significant impact on business interruption losses of the port. In this paper, a container crane’s seismic response is analyzed in ANSYS. First, a finite element model of a container crane is developed. Then, based on the equations of structural dynamics, the four most important modes of the container crane are extracted. Finally, a time history analysis is conducted to obtain the displacements of some critical nodes on the crane model under the excitation of an earthquake wave. The result of this paper provides a reference for the seismic design of container cranes.


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Xiaowei Wang ◽  
Yutao Pang ◽  
Aijun Ye

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.


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