scholarly journals Dynamic Failure Mode and Dynamic Response of High Slope Using Shaking Table Test

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Zhijun Zhou ◽  
Chenning Ren ◽  
Guanjun Xu ◽  
Haochen Zhan ◽  
Tong Liu
Keyword(s):  
Dynamic Response ◽  
Failure Modes ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Amplification Coefficient ◽  
Seismic Load ◽  
Dynamic Failure ◽  
High Slope ◽  
Amplification Effect ◽  
Slope Line

A shaking table test was performed to study the dynamic response and failure modes of high slope. Test results show that PGA amplification coefficients increased with increasing elevation and the PGA amplification coefficient of the concave slope was slightly larger than that of the convex slope. The slope type affected the dynamic response of the slope. The elevation amplification effect of the concave slope under seismic load was more significant than that of the convex slope; thus, the concave slope was more unstable than the convex slope. Additionally, the PGA amplification coefficient measured on the slope surface was always larger than that inside the slope, and the data show an increasing trend with the broken line. The dynamic amplification effect of the high slope was closely related to the natural frequency of the slope. Within a certain range, the higher the frequency, the more significant the amplification effect. The dynamic failure process of concave and convex slopes was studied through tests. Findings indicate that the dynamic failure modes of the concave slope are characterized by shoulder collapse, formation of the sliding surface, and integral sliding above the slope line. Dynamic failure modes of the convex slope are mainly slips in the soil layer and collapse of the slope near the slope line.

scholarly journals Response analysis of the nodes of pipe networks under seismic load

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247677
Author(s):  
Delong Huang ◽  
Aiping Tang ◽  
Qiang Liu ◽  
Dianrui Mu ◽  
Yan Ding
Keyword(s):  
Finite Element ◽  
Shaking Table Test ◽  
Element Model ◽  
Relative Displacement ◽  
Shaking Table ◽  
Amplification Coefficient ◽  
System Response ◽  
Response Analysis ◽  
Seismic Load ◽  
Pipe Network

Transient ground displacement (TGD) that is caused by earthquakes can damage underground pipes. This damage is especially critical for the joints, elbows and tees of the pipes which play an important role in the operation of a pipe network. In this study, a scale pipe network with both elbows and tees, as well as some components of the pipe network with only tees or elbows, has been investigated. The response of the nodes of a pipe network, when installed in non-uniform geology, was analyzed using the shaking table test and ABAQUS finite element simulation. This paper has firstly introduced the preparation of the test and the developed finite element model. Then the system response in terms of strain, the friction, the bending deformation, the node deformation amplification coefficient and the pipe-soil relative displacement along the pipe axis of the pipe network and two pipe network components have been analyzed explaining the correlation between these responses. Finally, the influence of elbows and tees on the pipe network was analyzed, and the conclusions that have been reached about how tees and elbows can change the response of a pipe network during an earthquake can provide theoretical support for the seismic design and layout of an underground pipe network.

scholarly journals Shaking Table Test on Dynamic Response of Bedding Rock Slopes With Weak Structural Plane Under Earthquake

2020 ◽  
Vol 8 ◽  
Author(s):  
Changwei Yang ◽  
Liang Zhang ◽  
Yang Liu ◽  
Denghang Tian ◽  
Xueyan Guo ◽  
...  
Keyword(s):  
Seismic Wave ◽  
Shaking Table Test ◽  
Surface Effect ◽  
Shear Plane ◽  
Shaking Table ◽  
Resonance Phenomenon ◽  
Amplification Coefficient ◽  
Structural Plane ◽  
Bedding Slope ◽  
Elevation Effect

Taking a bedding rock slope with weak structural plane as the prototype, a shaking table test with a similarity ratio of 1:10 is designed and carried out. By analyzing the acceleration and displacement responses at different positions of the slope, the seismic response and instability mechanism of rock bedding slope under different seismic amplitudes, frequencies, and durations are studied. Before the failure of the slope, the rock bedding slope shows an obvious “elevation effect” and “surface effect” under the action of Wenchuan Wolong earthquake wave with different amplitudes. With the increase of the amplitude of the input seismic wave, the elevation effect and the surface effect gradually weaken. When the amplitude of the seismic wave reaches 0.9 g, the rock bedding slope begins to show damage, which demonstrates that the difference of PGA amplification coefficients on both sides of the weak structural plane increases significantly. Compared with the Kobe seismic wave and Wenchuan Wolong seismic wave, the excellent frequency of EL Centro seismic wave is closer to the first-order natural frequency of slope model and produces resonance phenomenon, which leads to the elevation effect of PGA amplification coefficient more significantly. Through the analysis of the instability process of rock bedding slope, it can be found that the failure mechanism of the slope can be divided into two stages: the formation of sliding shear plane and the overall instability of the slope.

Study on Lateral Dynamic Response of Pile Foundation in Liquefiable Soil by Using FBG Method

2012 ◽  
Vol 238 ◽  
pp. 337-340 ◽  
Author(s):  
Yu Run Li ◽  
Yan Liang ◽  
Xing Wei ◽  
Yun Long Wang ◽  
Zhen Zhong Cao
Keyword(s):  
Dynamic Response ◽  
Data Acquisition ◽  
Pile Foundation ◽  
Maximum Stress ◽  
Shaking Table Test ◽  
Data Acquisition System ◽  
Seismic Damage ◽  
Shaking Table ◽  
Calculation Methods ◽  
Liquefiable Soil

The study on lateral dynamic response of pile foundation in liquefiable soil is a significant part about seismic damage. In this paper, a new data acquisition system of FBG and calculation methods is used in the small shaking table test. The results show that FBG method used in this test is proved to be efficient and acceptable in both time characteristics and precision characteristics, it may be widely applied in the future doubtlessly. What’s more, the characteristics of p-y curves in different peak accelerations are discussed. And varying of maximum stress and displacement by corresponding acceleration is discussed. A contrast about p-y curve between dry sand and saturate sand is related, which provides a new direction in research about p-y curve.

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.

scholarly journals Dynamic Response Characteristics of Aeolian Sediment along Sichuan-Tibet Railway

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Kan Han ◽  
Chunxiao Xue
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Shaking Table Test ◽  
Soil Layer ◽  
Time History ◽  
Surface Displacement ◽  
Shaking Table ◽  
Aeolian Sand ◽  
Response Characteristics ◽  
Dynamic Response Characteristics

In order to reduce the damage of liquefaction of aeolian sand along the Sichuan-Tibet railway, the dynamic response characteristics of saturated aeolian sand in the study area were discussed by using shaking table test. The results show that the macroscopic characteristics of saturated aeolian sand in the study area are subsidence, water flow and fracture. The displacement time history shows that the surface displacement increases with increasing the input ground motion acceleration. When the acceleration is small (0.1g), the vibration in the soil layer has an obvious tendency to enlarge continuously from bottom to top. With the increase of the acceleration (0.2g), the amplification trend basically disappeared. When the acceleration increases to 0.3g, the ground motion increases first and then decreases.

Improved Model Tests to Investigate the Failure Modes of Pipes Under Beyond Design Basis Earthquakes

2018 ◽  
Author(s):  
Izumi Nakamura ◽  
Naoto Kasahara
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Piping System ◽  
Input Frequency ◽  
Shaking Table Tests ◽  
Pure Lead ◽  
Design Basis ◽  
Improved Model

In order to investigate the failure modes of piping systems under the beyond design basis seismic loads, the authors proposed an experimental approach to use pipes made of the simulation material instead of steel pipes in the previous study. Though the ratchet-collapse (ratchet and subsequent collapse) was successfully obtained as the failure mode through the shaking table test using the pure lead (Pb) pipes as the simulation material pipe specimens, there was concern that characteristics of pure lead was somewhat extreme considering the analogy with the stress-strain relationship of steel. In order to resolve such concern, a modified experimental procedure has been developed. In the modified procedure, lead-antimony (Pb-Sb) alloy is used as the simulation material. Through the shaking table tests on single elbow pipe specimens made of Pb-Sb alloy, it is found that the typical failure mode is the ratchet and subsequent collapse, as same as the results by the shaking table tests of the Pb pipe specimens. The results indicate that the lower input frequency than the specimen’s natural frequency is prone to cause failure to the specimen, while the higher input frequency hardly causes the failure. The tendency of the global behavior of specimens is similar each other between the Pb pipe specimens and the Pb-Sb alloy specimens, but the strength of self-weight collapse of the Pb-Sb alloy pipe specimen is much higher than that of the Pb pipe specimen. Due to such higher strength of Pb-Sb alloy pipes, a prospect to conduct an excitation test on a more complicated piping system model is obtained.

scholarly journals Discrete Element Modeling of the Seismic Behavior of Masonry Construction

Buildings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 43 ◽  
Author(s):  
José Lemos
Keyword(s):  
Dynamic Analysis ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Shaking Table Test ◽  
Discrete Element ◽  
Shaking Table ◽  
Stone Masonry ◽  
Discrete Elements ◽  
Element Analysis ◽  
Masonry Construction

Discrete element models are a powerful tool for the analysis of masonry, given their ability to represent the discontinuous nature of these structures, and to simulate the most common deformation and failure modes. In particular, discrete elements allow the assessment of the seismic behavior of masonry construction, using either pushover analysis or time domain dynamic analysis. The fundamental concepts of discrete elements are concisely presented, stressing the issues related to masonry modeling. Methods for generation of block models are discussed, with some examples for the case of irregular stone masonry walls. A discrete element analysis of a shaking table test performed on a traditional stone masonry house is discussed, as a demonstration of the capabilities of these models. Practical application issues are examined, namely the computational requirements for dynamic analysis.

SSI Damping System Research Based on Discontinuity of the Motion

2011 ◽  
Vol 287-290 ◽  
pp. 2144-2147 ◽  
Author(s):  
Zhi Ying Zhang ◽  
Zhan Chao Gao ◽  
Ying Li
Keyword(s):  
Dynamic Response ◽  
Dynamic System ◽  
Soil Structure ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Soil Structure Interaction ◽  
System Research ◽  
Structure Interaction ◽  
Linear Elastic ◽  
Elastic Range

The Soil-Structure Interaction (SSI) Effect exists everywhere, but the existing researches on actual damping of SSI system are not so sufficient, and the analysis of its real dynamic response becomes unsuitable to engineering applications. In this paper, the possibility of regarding SSI system as classical damping system in linear elastic range is studied. The motion domains and the equation of the dynamic system in each domain are confirmed with respect to boundaries. The research on Shaking Table Test of SSI system is shown as an example of supporting the feasibility of regarding SSI system as classical damping system similarly.

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.

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