Seismic Response of a Viaduct under near-Fault Earthquakes

2012 ◽  
Vol 166-169 ◽  
pp. 2368-2372
Author(s):  
Yan Jiang Chen ◽  
Yu Bo Zhang ◽  
Wei Ming Yan ◽  
Yong Li
Keyword(s):  
Dynamic Response ◽  
Seismic Response ◽  
Time History ◽  
Response Patterns ◽  
Structural Dynamic ◽  
Near Fault ◽  
Large Velocity ◽  
Time History Response ◽  
Near Fault Earthquakes ◽  
Periodic Components

Abundant long-periodic components endue near-fault earthquakes with large velocity pulses while the viaducts owe long periodic fundamental period. To explore the seismic response patterns of viaducts under near-fault earthquakes, the paper analyzed the time history response of a viaduct under near-fault seismograms including TCU 1063, TCU 065, El centro and Artificial wave via FEM software Civil. The analysis shows a significant boost in near-fault seismic response as the value of PGV/PGA increased accordingly, indicates that the near-fault pulse affects strongly on the structural dynamic response of the viaducts.

scholarly journals Effects of Near Fault and Far Fault Ground Motions on Nonlinear Dynamic Response and Seismic Improvement of Bridges

2018 ◽  
Vol 4 (6) ◽  
pp. 1456 ◽  
Author(s):  
Mohammad Hajali ◽  
Abdolrahim Jalali ◽  
Ahmad Maleki
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Relative Displacement ◽  
Near Fault ◽  
Acceleration Rate ◽  
Near Fault Earthquakes ◽  
Far Fault

In this study, the dynamic response of bridges to earthquakes near and far from the fault has been investigated. With respect to available data and showing the effects of key factors and variables, we have examined the bridge’s performance. Modeling a two-span concrete bridge in CSI Bridge software and ability of this bridge under strong ground motion to near and far from fault has been investigated. Nonlinear dynamic analysis of time history includes seven records of past earthquakes on models and it was observed that the amount of displacement in the near faults is much greater than the distances far from faults. Bridges designed by seismic separators provide an acceptable response to a far from fault. This means that in bridges using seismic separators, compared to bridges without seismic separators, Acceleration rate on deck, base shearing  and the relative displacement of the deck are decrease. This issue is not seen in the response of the bridges to the near faults. By investigating earthquakes near faults, it was observed that near-fault earthquakes exhibit more displacements than faults that are far from faults. These conditions can make seismic separators critical, so to prevent this conditions FDGM should be used to correct the response of these bridges. Based on these results, it can be said that the displacement near faults with forward directivity ground motion is greater than far from faults. So that by reducing the distance from the faults, the maximum value of the shearing and displacement of the deck will be greater.

scholarly journals Spectral analysis of multiple cracked beam subjected to moving load

2014 ◽  
Vol 36 (4) ◽  
pp. 245-254
Author(s):  
N. T. Khiem ◽  
P. T. Hang
Keyword(s):  
Dynamic Response ◽  
Moving Load ◽  
Time History ◽  
Theoretical Development ◽  
Multiple Cracks ◽  
Spectral Approach ◽  
Cracked Beam ◽  
Time History Response ◽  
Numerical Case Study

In present paper, the spectral approach is proposed for analysis of multiple cracked beam subjected to general moving load that allows us to obtain explicitly dynamic response of the beam in frequency domain. The obtained frequency response is straightforward to calculate time history response by using the FFT algorithm and provides a novel tool to investigate effect of position and depth of multiple cracks on the dynamic response. The analysis is important to develop the spectral method for identification of multiple cracked beam by using its response to moving load. The theoretical development is illustrated and validated by numerical case study.

Simulation of Time Histories of Second-Order Wave Effects by Pseudo-Linear Transformation

1995 ◽  
Vol 117 (2) ◽  
pp. 78-84
Author(s):  
Y. Li
Keyword(s):  
Dynamic Response ◽  
Time History ◽  
Second Order ◽  
Hilbert Transforms ◽  
Structural Dynamic ◽  
Quadratic Transformation ◽  
Wave Effects ◽  
Time Histories ◽  
Component Wave ◽  
The Time Domain

Simulation of the time histories of second-order wave effects is often performed by quadratic transformation of a wave time history. By the present approach, the quadratic transformation of waves is approximated by linear combinations of the products of component wave time records and their Hilbert transforms. The computational efficiency is greatly enhanced. The efficient quadratic transformation of a time history is for the time domain solution of structural dynamic response, and can also be used as a post-processor of the frequency domain solution for obtaining statistic parameters of dynamic response.

Seismic Response Analysis of Twin-Tower Building with Enlarged Base

2014 ◽  
Vol 912-914 ◽  
pp. 1534-1537
Author(s):  
Shao Bo Zhang ◽  
Ke Lun Wei ◽  
Bi Jian Xiao
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Boundary Conditions ◽  
Seismic Response ◽  
Time History ◽  
Response Analysis ◽  
Rigid Boundary ◽  
Finite Element Software ◽  
Elastic Boundary ◽  
Elastic Boundary Conditions

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.

Structural Surrogate Model and Dynamic Response Prediction with Consideration of Temporal and Spatial Evolution: An Encoder–Decoder ConvLSTM Network

2021 ◽  
pp. 2150140
Author(s):  
Hong Peng ◽  
Jingwen Yan ◽  
Ying Yu ◽  
Yaozhi Luo
Keyword(s):  
Dynamic Response ◽  
Surrogate Model ◽  
Structural Model ◽  
Short Term Memory ◽  
Time History ◽  
Response Prediction ◽  
Surrogate Models ◽  
Hybrid Network ◽  
Spatiotemporal Evolution ◽  
Structural Dynamic

In this paper, a new deep learning framework named encoding convolution long short-term memory (encoding ConvLSTM) is proposed to build a surrogate structural model with spatiotemporal evolution of structure, estimate the structural spatiotemporal state and predict the dynamic response under similar future dynamic load conditions. The main work of this study includes: (a) The spatiotemporal response tensor database is developed using discrete-time history data of structural dynamic response. (b) As an extension of LSTM, convolution operation is combined with LSTM network to construct structural surrogate model from the spatiotemporal evolution structural performance. (c) To enhance the anti-interference ability of structural surrogate models, a new three-layer encoding layer is added for denoising autoencoders of the hybrid network. The influence of building types and input noise on the accuracy and antinoise performance of the surrogate models are analyzed through the dynamic response prediction of a frame-shear wall, a cylindrical, and a spherical reticulated shell structure. As a testbed for the proposed network, a case study is performed on a laboratory stadium structure. The results demonstrate that the developed surrogate model can predict the structural dynamic response precisely with more under 30% noise interference.

Shaking Table Test of Underground Pipeline under Three Dimension Seismic Excitation – Numerical Simulation

2014 ◽  
Vol 919-921 ◽  
pp. 960-964 ◽  
Author(s):  
Xiao Fu ◽  
Jun Wei Bi ◽  
Zhi Jia Wang ◽  
Chang Wei Yang
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Seismic Response ◽  
Shaking Table Test ◽  
Time History ◽  
Shaking Table ◽  
Seismic Excitation ◽  
Underground Pipeline ◽  
Three Dimension ◽  
Seismic Structure

Based on the design of the large-scale shaking table test of an underground pipeline under three dimension seismic excitation, the dynamic response of the soil-structure is analyzed by using ANSYS. In the numerical simulation, Drucker-Prager constitutive model is adopted to simulate the soil, the interface between soil and pipeline are simulated with zero thickness contact elements, size effects of test box are diminished by defining viscoelastic boundary around soil, the acceleration time history curve of the original earthquake wave is compressed and processed according to using the model scale similarity and energy duration which is presented by Trifunac-Brady [1] , and then the characteristic of seismic response of the pipeline can be found. The results show that the top of pipeline is the seismic response intense regional, deformation displacements of the central areas at the bottom and top of pipeline are always larger than others, the entrance and exit are the weak positions of anti-seismic structure; moreover, the dynamic response and interactions of soil-pipeline in the model experiment can be more accurately simulated by the methods presented in the paper. Thus, it can be served as reference for the design and construction of subsurface structures.

Space Seismic Response Analysis of City Elevated Curved Box Girders Bridge

2011 ◽  
Vol 255-260 ◽  
pp. 1096-1101
Author(s):  
Qing Zhao
Keyword(s):  
Seismic Response ◽  
Three Dimensional ◽  
Time History ◽  
Internal Force ◽  
Response Analysis ◽  
Box Girders ◽  
Element Analysis ◽  
History Analysis ◽  
The Finite Element Analysis ◽  
Time History Response

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.

Evaluation of Seismic Behavior on Steel Frames with TSW Semi-Rigid Connections under the Nonlinear Time History Analysis

2012 ◽  
Vol 166-169 ◽  
pp. 2083-2087
Author(s):  
Miaad Najdian ◽  
Mohsen Izadinia
Keyword(s):  
Time History ◽  
High Energy ◽  
Time History Analysis ◽  
Nonlinear Time History Analysis ◽  
Near Fault ◽  
Good Ability ◽  
History Analysis ◽  
Ductile Behavior ◽  
Near Fault Earthquakes ◽  
Nonlinear Time History

Movements of pulse shape and the high energy applied in short duration by the near fault earthquake, causes brittle fracture in rigid connections that during the Northridge 1994 and Kobe 1995 earthquakes was frequently seen. Rigid connections, which are generally welded due to lack of ductility, have low energy absorption capability. On the other hand semi-rigid connections have a ductile behavior and have a good ability to absorb energy. The purpose of this paper is analysis and compares the behaviors of “rigid” and “TSW semi-rigid” connections under the near fault earthquakes with nonlinear time history analysis by perform 3D software.

scholarly journals Seismic Behavior of a Class of Mixed Reinforced Concrete-Steel Buildings Subjected to Near-Fault Motions

2021 ◽  
Vol 6 (12) ◽  
pp. 172
Author(s):  
Paraskevi K. Askouni ◽  
George A. Papagiannopoulos
Keyword(s):  
Reinforced Concrete ◽  
Seismic Response ◽  
Seismic Design ◽  
Seismic Behavior ◽  
Time History ◽  
Steel Buildings ◽  
Seismic Codes ◽  
Near Fault ◽  
Non Linear ◽  
Story Drift

This paper investigates the seismic behavior of a class of mixed reinforced concrete­–­steel buildings. In particular, mixed buildings constructed by r/c (reinforced concrete) at their lower story(ies) and structural steel at their upper story(ies) are studied from the viewpoint of their wide application in engineering praxis. The need to investigate the seismic behavior for this type of mixed buildings arises from the fact that the existent literature is small and that modern seismic codes do not offer specific seismic design recommendations for them. To study the seismic behavior of mixed r/c-steel buildings, a 3-D numerical model is employed and five realistic r/c-steel mixed buildings are simulated. Two cases of the support condition, i.e., fixed or pinned, of the lowest steel story to the upper r/c one are examined. The r/c and steel parts of the mixed buildings are initially designed as separate structures by making use of the relevant seismic design guidelines of Eurocode 8, and then the seismic response of these buildings is computed through non-linear time-history analyses. The special category of near-fault seismic motions is selected in these time-history analyses to force the mixed r/c-steel buildings under study to exhibit a strong non-linear response. Seismic response indices in terms of inter-story drift ratio, residual inter-story drift ratio and peak floor absolute accelerations are computed. The maximum values of these indices are discussed by comparing the two aforementioned kinds of support conditions and checking the satisfaction of specific seismic performance limits. Conclusions regarding the expected seismic behavior of mixed r/c-steel buildings under near-fault seismic motions are drawn. Finally, the need to introduce specific design recommendations for mixed r/c-steel buildings in modern seismic codes is stressed.

Sign in / Sign up

Export Citation Format

Share Document