scholarly journals Dynamic Response of Parallel Overlapped Tunnel under Seismic Loading by Shaking Table Tests

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Tao Yang ◽  
Yunkang Rao ◽  
Honggang Wu ◽  
Junyun Zhang ◽  
Hao Lei ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wavelet Packet ◽  
Failure Process ◽  
Side Wall ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Dynamic Strain ◽  
Shaking Table Tests ◽  
Failure Characteristics ◽  
The Right

Potential earthquake-induced damage to overlapped tunnels probably occurs during the operation and maintenance of mountain tunnel engineering, especially in the seismically active zone. This study investigated the dynamic response and the failure characteristics of the parallel overlapped tunnel under seismic loadings by employing shaking table tests. The failure mode of the parallel overlapped tunnels was analyzed through macroscopic test phenomena. The dynamic responses of the surrounding rock and tunnel lining were evaluated by acceleration and dynamic strain, respectively. In particular, wavelet packets were used to investigate the spectrum characteristics of the tunnel structure in depth. The failure process of the model can be divided into three stages. The upper-span and the under-crossing tunnels showed different failure characteristics. Additionally, the lining damage on the outer surface of the tunnel mainly occurred on the right side arch waist and the left side wall, whereas the lining damage on the inner surface of the tunnel mainly appeared on the crown and invert. Wavelet packet energy results showed that the energy characteristic distributions of the upper-span and the under-crossing tunnels were not consistent. Specifically, the energy eigenvalues of the crown of the upper-span tunnel and the invert of the under-crossing tunnel were the largest, which should be considered to be the weak parts in the seismic design.

scholarly journals Shaking Table Tests for Seismic Response of Oblique Overlapped Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hao Lei ◽  
Honggang Wu ◽  
Tianwen Lai
Keyword(s):  
Seismic Response ◽  
Cross Section ◽  
Slope Failure ◽  
Response Spectrum ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Dynamic Strain ◽  
Seismic Load ◽  
Shaking Table Tests ◽  
The Cross

To study the dynamic response and spectrum characteristics of the three-dimensional crossing tunnel under the action of seismic load, we established a 1/50 downscale model based on a typical of the oblique overlapped tunnel and conducted a series of shaking table tests. Through examining the recorded dynamic responses (acceleration and dynamic strain measured at different locations in model tunnels), we found that the seismic response of the crown was the largest at the central section, and the invert of the tunnels was exactly opposite to the crown, which presented a “parabolic” distribution, and we inferred that the damage within the model may be mainly concentrated on the crown of the tunnels. Additionally, the dynamic strain showed obvious nonlinear and nonstationary characteristics under the action of different degrees of seismic intensities. Different from a single tunnel, the acceleration superposition effect appears in the cross section of two tunnels because of the spatial effect of overlapping tunnels, resulting in the obvious seismic response in the cross section. Meanwhile, we also found that the 1st dominant frequency (0.1–6.26 Hz) seismic wave played a leading role in the process of tunnel slope failure. Furthermore, the analysis of the acceleration response spectrum also showed that the surrounding rock mass has an amplification effect on low-frequency seismic waves. These results help us better understand the features of the dynamic responses and also provide evidence to reinforce the overlapped tunnels against earthquakes.

Analysis of Seismic Dynamic Response of Tunnel in Karst Areas

2011 ◽  
Vol 90-93 ◽  
pp. 2108-2111
Author(s):  
Lin Jie Chen ◽  
Bo Liang ◽  
Zhi Yong Wang
Keyword(s):  
Dynamic Response ◽  
Soil Structure ◽  
Interaction Model ◽  
Time History ◽  
Side Wall ◽  
Internal Force ◽  
Dynamic Responses ◽  
Karst Caves ◽  
History Analysis ◽  
Karst Areas

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.

Dynamic Responses of RC Underground Subway Station and Soil during the Strong Earthquake

2011 ◽  
Vol 194-196 ◽  
pp. 2018-2023
Author(s):  
Jin Bian ◽  
Lian Jin Tao ◽  
Wen Pei Wang ◽  
Bo Zhang
Keyword(s):  
Underground Structure ◽  
Time History ◽  
Side Wall ◽  
Relative Displacement ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Subway Station ◽  
Rc Structures ◽  
Underground Subway Station ◽  
Table Model

Underground subway RC structures suffered significant damage during many earthquakes, so it is important to study the seismic behavior on RC subway structure. The shaking table model test is made of the Beijing typical subway station structure. In this article, the test is introduced briefly; then, the acceleration history curves are analyzed. By the test, it is found that the interaction exits between structure and soil. Under the low intensity earthquake, the underground structure will exert a very small influence on soil and vibrates with soil; under the high intensity earthquake, the soil will exert a large thrust on the underground structure and the relative displacement exists between them. Moreover, At the bottom of the structure side wall, the peak acceleration is larger than it in soil around the place, and at the top and middle of the structure side wall, the peak accelerations are smaller than them in soil around the place; with the depth increase, decrease the peak value, the excellence frequency and its amplitude of the acceleration time history.

scholarly journals Shaking Table Tests for Seismic Response of Orthogonal Overlapped Tunnel under Horizontal Seismic Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Honggang Wu ◽  
Hao Lei ◽  
Tianwen Lai
Keyword(s):  
Dynamic Response ◽  
Seismic Response ◽  
Seismic Wave ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Acceleration Response ◽  
Test Device ◽  
Deformation Stages ◽  
Superposition Effect

This paper presents the seismic dynamic response and spectrum characteristics of an orthogonal overlapped tunnel by shaking table tests. First, a prototype of the engineering and shaking table test device, which was used to design details of the experiment, was developed. Then, the sensors used in the test were selected, and the measurement points were arranged. Subsequently, the Wenchuan seismic wave with horizontal direction in different peak ground accelerations was inputted into the model, followed by a short analysis of the seismic response of the overlapped tunnel in the shaking table test as well as the distribution of the peak acceleration. Throughout the studies, the model exhibited obvious deformation stages during the seismic wave loading process, which can be divided into elastic, plastic, plastic enhancement, and failure stage. In particular, the time- and frequency-domain characteristics of the key parts of the tunnel were discussed in detail by using the continuous wavelet transform (CWT) based on the Morlet wavelet as the basis function. We found that the acceleration response was more intense within 25–60 s after the seismic wave was inputted. Furthermore, owing to “the superposition effect,” the seismic response at the crown of the under-crossing tunnel was stronger than that at the invert of the upper-span tunnel. The low and medium frequencies in the transformation of small scales (5–20) significantly affected the overlapped tunnel. These results elucidate the seismic dynamic response of the overlapped tunnel and provide guidance for the design of stabilizing structures for reinforcing tunnels against earthquakes.

Dynamic Response in ALF Aggregate Base Asphalt Pavement

2011 ◽  
Vol 97-98 ◽  
pp. 40-44 ◽  
Author(s):  
Chuan Yi Zhuang ◽  
Ai Qin Shen ◽  
Lin Wang
Keyword(s):  
Dynamic Response ◽  
Compressive Stress ◽  
Asphalt Pavement ◽  
Compressive Strain ◽  
Full Scale ◽  
Dynamic Responses ◽  
Traffic Load ◽  
Dynamic Strain ◽  
Strain Response ◽  
Soil Pressure

In order to evaluate pavement dynamic responses accurately under truck loading, the full-scale asphalt pavement accelerated loading facility (ALF) was used. 10 strain gauges and 2 soil pressure cells were installed; temperature sensors were also installed in the different depth of the HMA layer. Pavement response was measured under real traffic load with ALF. The measured pavement responses are compared between the pavement sections to evaluate the effects of various experimental factors, such as axle load, speed, et al. Dynamic strain at the bottom of HMA layer and vertical compressive stress on the top of the subgrade were examined in the full-scale testing road, the regression models between dynamic response and axle load, dynamic response and speed were put forward respectively. Studies show that there is not only tensile strain but also compressive strain in the dynamic response, and the strain response is in the station of tension and compression alternation. Under the intermediate temperature, the strain response at the bottom of the asphalt layer is increased linearly with the increase of axle load and the vertical compressive stresses at the top of the subgrade is also increased with the increase of axle load. Speed has a great effect on strain response at the bottom of HMA layer, and has little effect on vertical compressive stress, it affects the loading duration of stress only. The destroy for the pavement by low speed and heavy load is more serious than that is normal.

scholarly journals Shaking table tests for dynamic response of a wharf with coupled batter piles.

2001 ◽  
pp. 101-113 ◽  
Author(s):  
Junji HAMADA ◽  
Takahiro SUGANO ◽  
Tatsuo UWABE ◽  
Shigeru UEDA ◽  
Hiroshi YOKOTA
Keyword(s):  
Dynamic Response ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Batter Piles

Testing and Statistics Analysis on Dynamic Response of Expressway Bridge under Various Vehicles

2011 ◽  
Vol 90-93 ◽  
pp. 1033-1038
Author(s):  
Tao Wang ◽  
Wan Shui Han ◽  
Yan Wei Li
Keyword(s):  
Dynamic Response ◽  
Rapid Development ◽  
Bridge Engineering ◽  
Dynamic Responses ◽  
Critical Parameters ◽  
Dynamic Strain ◽  
Coupling Vibration ◽  
Vehicle Type ◽  
Traffic Lane ◽  
Video Recorder

Nowadays, with the rapid development of the traffic infrastructure construction and the growing of the traffic flowing and speed, the vehicle-bridge coupling vibration research has become the focus of the bridge engineering study. The dynamic response of the bridge under the traffic flowing is one of the vital parameters for the vehicle-bridge coupling vibration analysis. In this paper, a methodology, employing the speed radar gun, the video recorder, and the dynamic strain tester in combination with manually recording is used to continuously and detailed investigate the traffic loads on the expressway bridge within 24 hours a day. With this approach introduced by this paper, all the critical parameters, such as the vehicle type, speed, traffic lane, the arriving time of the traffic and the bridge-vehicle dynamic interaction are all recorded. In this investigation, firstly the dynamic responses of 8 pieces of girders of the bridge under 5650 individual vehicles driving through the bridge are recorded, then in conjunction with the investigated traffic flowing samples, in terms of the vehicle type, some detailed statistics study is conducted on the collected records, and finally the space-time distribution laws of the dynamic response of the bridge under the traffic flowing are studied extensively. The result of this study could provide helpful theoretic guidance and supporting data for the vehicle-bridge coupling vibration research.

Experimental Study on Seismic Failure of High Arch Dam with Scale Model Test on Shaking Table

2013 ◽  
Vol 353-356 ◽  
pp. 2004-2007
Author(s):  
Peng Fei Gao ◽  
Xin Feng ◽  
Jing Zhou
Keyword(s):  
Shaking Table Test ◽  
Failure Process ◽  
Arch Dam ◽  
Shaking Table ◽  
Scale Model ◽  
Experimental Investigations ◽  
Shaking Table Tests ◽  
High Arch Dam ◽  
Structural Concrete ◽  
Concrete Material

This paper presents the experimental investigations into the seismic failure for high arch dam with shaking table test. The similitude scale of high arch dam was studied firstly. Then we developed a like concrete material to simulate the mechanical behavior of the structural concrete in high arch dam. The shaking table tests have been performed on the scale model. The experimental results reveal the failure process of high arch dam with respect to the different earthquake intensities.

Prediction of the Dynamic Response of a Ship in Head Waves Using OpenFOAM Toolbox

2020 ◽  
Vol 162 (A1) ◽  
Author(s):  
J Yao
Keyword(s):  
Dynamic Response ◽  
Dynamic Responses ◽  
Navier Stokes ◽  
Design Stage ◽  
Offshore Platforms ◽  
Computational Domain ◽  
Marine Structures ◽  
Time Step ◽  
Head Waves ◽  
The Right

Ships and marine structures, such as oil tanker, offshore platforms, etc., usually face extreme seaway environment in real situation. If under the action of strong waves large amplitude motions will occur, with the result that they may not work as usual or even lose stability. Thus, it is of great importance to access their dynamic responses under such bad conditions at the initial design stage, so as to ensure normal usage and safety. Herein, the original RANS (Reynolds-Averaged Navier-Stokes) solver based on OpenFOAM Toolbox has been extended to predict dynamic responses of ships and marine structures in waves. A new “inlet-velocity boundary condition” was implemented to generate waves. A damping term for wave absorption was added to the right-hand side of RANS equations in order to avoid wave reflection from the boundary where waves leave the computational domain. The related numerical methods are described in this paper. The purpose of this paper is to present a validation of the approach used. The prediction of the dynamic response of a ship in head waves was the focus. Five cases with different wave lengths and heights were considered. The predicted results, i.e. time histories of total resistance, heave and pitch, were compared with available experimental data and analysed. In addition, due to current experience it is very necessary that effort is devoted to determining appropriate grid and time step, so as to ensure the quality of waves generated.

Sign in / Sign up

Export Citation Format

Share Document