Seismic Response of Gravity Dam under Oblique Incidence of Seismic Waves

2013 ◽  
Vol 838-841 ◽  
pp. 1585-1590
Author(s):  
Li Chen ◽  
Liao Jun Zhang
Keyword(s):  
Seismic Response ◽  
Oblique Incidence ◽  
Seismic Waves ◽  
Near Field ◽  
P Wave ◽  
Gravity Dam ◽  
Response Analysis ◽  
Uniform Motion ◽  
Obvious Effect ◽  
Obliquely Incident

The selection of proper seismic input is essential for seismic response analysis of the gravity dam structures. For the near-field earthquakes, the direction of seismic waves is not always considered as vertical. The non-uniform motion produced by oblique incidence can cause significant influence to the structure. In this study, the obliquely incident method is applied in the finite element model of a typical section of a gravity dam located in southwestern China. The seismic response under obliquely incident of plane P wave and plane SV with different incident angles and tilt directions are discussed. The results show that the oblique incidence has an obvious effect on the seismic response of the gravity dam, and the inconsistence produced by oblique incidence cannot be neglected.

A Seismic Wave Oblique Incidence Method and the Application in Gravity DAM Seismic Research

2014 ◽  
Vol 08 (04) ◽  
pp. 1450011 ◽  
Author(s):  
Li Chen ◽  
Liaojun Zhang
Keyword(s):  
Seismic Wave ◽  
Oblique Incidence ◽  
Large Scale ◽  
Seismic Waves ◽  
Seismic Analysis ◽  
Near Field ◽  
P Wave ◽  
Gravity Dam ◽  
Uniform Motion ◽  
Element Analysis

The incidence of seismic wave is generally assumed to be vertical in seismic analysis of large-scale hydraulic structures, but during some near-field earthquakes, the direction of seismic waves is at certain angle to the ground. The non-uniform motion produced by oblique incidence can significantly affect the structures. In this paper, based on the theories of wave motion an oblique P-wave and SV-wave incidence method based on viscous-spring boundary was introduced into finite element analysis, which can accurately simulate the incidence at different oblique angles. Then the proposed method was applied in seismic analysis of a gravity dam located in southwest China. The seismic responses under oblique incidence of P-wave and SV-wave at different oblique angles were discussed. The results indicated that the seismic response was obviously influenced by the oblique incidence, and the traditional vertical incidence was unsuitable for some near-field earthquakes. The oblique incidence should be considered in the seismic analysis of high dams as well as other large-scale water-retaining structures located in seismic regions.

Elasto-Plastic Analysis of Seismic Response of Valve-Hall Structure with Suspension Valves of Large-Scale Converter Station

2011 ◽  
Vol 94-96 ◽  
pp. 1941-1945
Author(s):  
Yi Wu ◽  
Chun Yang ◽  
Jian Cai ◽  
Jian Ming Pan
Keyword(s):  
Seismic Response ◽  
Large Scale ◽  
Seismic Waves ◽  
Tensile Force ◽  
Response Analysis ◽  
Vertical Acceleration ◽  
Seismic Responses ◽  
Seismic Response Analysis ◽  
Finite Element Software ◽  
Plastic Analysis

Elasto-plastic analysis of seismic responses of valve hall structures were carried out by using finite element software, and the effect of seismic waves on the seismic responses of the valve hall structures and suspension equipments were studied. Results show that significant torsional responses of the structure can be found under longitudinal and 3D earthquake actions. Under 3D earthquake actions, the seismic responses of the suspension valves are much more significant than those under 1D earthquake actions, the maximum tensile force of the suspenders is about twice of that under 1D action. The seismic responses of the suspension valves under vertical earthquake actions are much stronger than those under horizontal earthquake actions, when suffering strong earthquake actions; the maximum vertical acceleration of the suspension valves is about 4 times of that under horizontal earthquake actions. It is recommended that the effects of 3D earthquake actions on the structure should be considered in seismic response analysis of the valve hall structure.

Are Synthetic Accelerograms Suitable for Local Seismic Response Analyses at Near-Field Sites?

2021 ◽  
Author(s):  
Francesca Mancini ◽  
Sebastiano D’Amico ◽  
Giovanna Vessia
Keyword(s):  
Seismic Response ◽  
Seismic Waves ◽  
Near Field ◽  
Central Italy ◽  
Propagation Path ◽  
Soil Behavior ◽  
Seismic Stations ◽  
Seismic Input ◽  
Local Seismic Response ◽  
Finite Fault

ABSTRACT Local seismic response (LSR) studies are considerably conditioned by the seismic input features due to the nonlinear soil behavior under dynamic loading and the subsurface site conditions (e.g., mechanical properties of soils and rocks and geological setting). The selection of the most suitable seismic input is a key point in LSR. Unfortunately, few recordings data are available at seismic stations in near-field areas. Then, synthetic accelerograms can be helpful in LSR analysis in urbanized near-field territories. Synthetic accelerograms are generated by simulation procedures that consider adequately supported hypotheses about the source mechanism at the seismotectonic region and the wave propagation path toward the surface. Hereafter, mainshocks recorded accelerograms at near-field seismic stations during the 2016–2017 Central Italy seismic sequence have been compared with synthetic accelerograms calculated by an extended finite-fault ground-motion simulation algorithm code. The outcomes show that synthetic seismograms can reproduce the high-frequency content of seismic waves at near-field areas. Then, in urbanized near-field areas, synthetic accelerograms can be fruitfully used in microzonation studies.

scholarly journals Seismic Ground Response Analysis Based on Multilayer Perceptron and Convolution Neural Networks

2021 ◽  
Vol 21 (1) ◽  
pp. 231-238
Author(s):  
Seokgyeong Hong ◽  
Jaehun Ahn
Keyword(s):  
Neural Networks ◽  
Seismic Response ◽  
Multilayer Perceptron ◽  
Seismic Waves ◽  
Ground Surface ◽  
Average Error ◽  
Response Analysis ◽  
Ground Response Analysis ◽  
Analysis Process ◽  
Specific Frequency

The importance of establishing a disaster prevention plan considering seismic performance is being highlighted to reduce damage to structures caused by earthquakes. Earthquake waves propagate from the bedrock to the ground surface through the soil. During the transmission process, they are amplified in a specific frequency range, and the degree of amplification depends mainly on the characteristics of the ground. Therefore, a seismic response analysis process is essential for enhancing the reliability of the seismic design. We propose a model for predicting seismic waves on the surface from seismic waves measured on the bedrock based on Multilayer Perceptron (MLP) and Convolutional Neural Networks (CNN) and validate the applicability of the proposed model with Spectral Acceleration (SA). Both the proposed models based on MLP and CNN successfully predicted the seismic response of the surface. The CNN-based model performed better than the MLP-based model, with a 10% smaller average error. We plan to implement the physical properties of the ground, such as shear wave velocity, to create a more versatile model in the future.

Seismic Response Analysis of Railway Continuous Curved Rigid Frame Bridges

2013 ◽  
Vol 353-356 ◽  
pp. 1846-1849
Author(s):  
Wen Jia Suo ◽  
Bing Zhu ◽  
Ning Zhao ◽  
Fan Wang ◽  
Sheng Tan Dou
Keyword(s):  
Seismic Response ◽  
Seismic Waves ◽  
Time History ◽  
Small Radius ◽  
Response Analysis ◽  
Rigid Frame ◽  
Maximum Reaction ◽  
Rigid Frame Bridge ◽  
Critical Sections ◽  
Response Feature

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.

Seismic Response Analysis of Unequal Altitude Double-Tower Connecting Structure with the Changes of Connecting Beam Location

2010 ◽  
Vol 163-167 ◽  
pp. 4043-4047
Author(s):  
Jin Song Lei ◽  
Qing Ma ◽  
Bo Xue
Keyword(s):  
Seismic Response ◽  
Shear Force ◽  
Seismic Waves ◽  
Horizontal Displacement ◽  
Structural Vibration ◽  
Response Analysis ◽  
Maximum Displacement ◽  
Vibration Period ◽  
Finite Element Software ◽  
Maximum Shear Force

Dynamic characteristics and seismic response for unequal height double-tower structure models were analyzed by finite element software. The effort of the connecting beam location changes to the structural vibration period, the maximum displacement on top and the maximum shear force at bottom were analyzed and compared. The results indicate that horizontal displacement under the seismic waves in x direction is larger than the displacement under seismic waves in y direction. When the locations of the connecting body vary, the influence to structural vibration period is different as vibration modes change. The effort to the maximum shear force of the structure at bottom under the seismic waves in x direction is larger than the displacement in y direction. The above results provide references for design and further studying.

Finite Element Seismic Response Analysis of a Reinforced Concrete Pier with a Fractured Fine Tetrahedron Mesh

2016 ◽  
Vol 10 (05) ◽  
pp. 1640013
Author(s):  
Shigenobu Okazawa ◽  
Takumi Tsumori ◽  
Takuzo Yamashita ◽  
Satoyuki Tanaka
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Seismic Response ◽  
Seismic Waves ◽  
Element Model ◽  
Response Analysis ◽  
Analysis Model ◽  
Seismic Response Analysis ◽  
Seismic Experiment ◽  
Node Connectivity

A seismic response analysis of a reinforced concrete (RC) pier has been undertaken using seismic waves recorded at the Takatori station during the southern Hyogo perfecture earthquake in 1995 in Japan. Distinguishing characteristics of this analysis are as follows. First, the RC pier has been modeled using the finite element method with a solid mesh. The analysis model has been generated using tetrahedral elements with node connectivity, not only in the concrete but also in the reinforcement steel. Also, an analysis has been undertaken on fracture treatments in the concrete. Using PDS-FEM, a system of suitable fractures in the concrete resulting from the seismic event can be simulated. Ultimately, a finite element model is established with a fine tetrahedron mesh with about 20 million elements. We calculate a seismic response analysis using the K computer at the RIKEN Advanced Institute for Computational Science, and compare that result with a seismic experiment in E-Defense to confirm the computational approach.

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