scholarly journals Application of BRFP New-Type Anchor Cable Material in High Slopes against Earthquakes

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Honggang Wu ◽  
Zhixin Wu ◽  
Hao Lei ◽  
Tianwen Lai
Keyword(s):  
Dynamic Response ◽  
Seismic Wave ◽  
Seismic Waves ◽  
Response Spectrum ◽  
Basalt Fiber ◽  
Shaking Table ◽  
Measuring Point ◽  
Reinforced Plastics ◽  
Short Period ◽  
The Impact

To clarify the feasibility of BFRP (basalt fiber reinforced plastics) anchors instead of steel anchors in the seismic application of slopes under different vibration strengths, a series of shaking table tests were carried out to strengthen the slope using BFRP anchors and steel anchors, respectively. By studying the dynamic response recorded in the slope model and the observed experimental phenomena, the acceleration dynamic response and displacement spectrum dynamic response of the two slope models were analyzed. The test results show that the deformation stage of the slope reinforced by the two types of anchors is basically the same during the test, that is, elastic, plastic (potential sliding surface and plastic strengthening), and failure stages, respectively. The slope is in the elastic stage before the 0.2 g seismic wave, and it gradually enters the plastic stage after the 0.4 g seismic wave. However, the peak acceleration and displacement of the slope reinforced by steel anchors are greater than those of the slope reinforced by BFRP anchors under the same working conditions of seismic waves. In addition, we found that the acceleration response spectrum distribution curve of each measuring point in the short period has an obvious amplification effect along the elevation, and its predominant period has a forward migration phenomenon with the increase of the height of the measuring point, which also indicates that the higher frequency seismic wave has a greater impact on the top of the slope. The BFRP anchors, as a kind of flexible structure supporting slope, can effectively reduce the impact of seismic waves on the slope and attenuate seismic waves to a certain extent compared with steel anchors. Furthermore, the BFRP anchors can be deformed in coordination with the slope, which can improve the overall working performance of the slope, especially limit the dynamic response of the middle and lower slopes. These results can provide a theoretical guide for the seismic design of BFRP anchors for high slopes.

scholarly journals Near-Field Measurement of Six Degrees of Freedom Mining-Induced Tremors in Lower Silesian Copper Basin

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6801
Author(s):  
Krzysztof Fuławka ◽  
Witold Pytel ◽  
Bogumiła Pałac-Walko
Keyword(s):  
Seismic Wave ◽  
Degrees Of Freedom ◽  
Seismic Waves ◽  
Near Field ◽  
High Energy ◽  
Rotational Component ◽  
Empirical Formulas ◽  
Six Degrees Of Freedom ◽  
The Impact

The impact of seismicity on structures is one of the key problems of civil engineering. According to recent knowledge, the reliable analysis should be based on both rotational and translational components of the seismic wave. To determine the six degrees of freedom (6-DoF) characteristic of mining-induced seismicity, two sets of seismic posts were installed in the Lower Silesian Copper Basin, Poland. Long-term continuous 6-DoF measurements were conducted with the use of the R-1 rotational seismometer and EP-300 translational seismometer. In result data collection, the waveforms generated by 39 high-energy seismic events were recorded. The characteristic of the rotational component of the seismic waves were described in terms of their amplitude and frequency characteristics and were compared with translational measurements. The analysis indicated that the characteristic of the rotational component of the seismic wave differs significantly in comparison to translational ones, both in terms of their amplitude and frequency distribution. Also, attenuation of rotational and translational components was qualitatively compared. Finally, the empirical formulas for seismic rotation prediction in the Lower Silesian Copper Basin were developed and validated.

Shaking Table Test of Muti-Story Subway Station Considering Soil-Structure Interaction

2013 ◽  
Vol 694-697 ◽  
pp. 321-324 ◽  
Author(s):  
Shu Wei Wang ◽  
Ying Ming Zhou ◽  
Shu Yun Mi
Keyword(s):  
Seismic Waves ◽  
Shaking Table Test ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Soil Surface ◽  
Shaking Table ◽  
Subway Station ◽  
Acceleration Process ◽  
Underground Structures

In this paper, a three-dimensional shaking table test of three three-span subway station model is done. Three test seismic waves were selected in this experiment, which were applied to the model. Modal analysis of the structure was done, and the determination of the acceleration of the model structure was obtained. And the law of underground structures under earthquake damage was analysis. Soil surface acceleration process and its response spectrum and strain are obtained in the different amplitudes of ground motion input case. From experiment cracks in the emergence and development of the situation were observed, and which gives recommendations for the seismic design of underground structures.

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 Effects of Three-Directional Seismic Wave on Dynamic Response and Failure Behavior of High-Steep Rock Slide

2021 ◽  
Vol 12 (1) ◽  
pp. 20
Author(s):  
Ziwei Ge ◽  
Hongyan Liu
Keyword(s):  
Dynamic Response ◽  
Seismic Wave ◽  
Seismic Waves ◽  
Vertical Direction ◽  
Failure Behavior ◽  
Rock Slide ◽  
Different Types ◽  
Process Failure ◽  
Directional Wave ◽  
East West

The landslide triggered by earthquakes can cause severe infrastructure losses or even fatalities. The high-steep rock slide is the most common type of landslide in the earthquake area. In an earthquake, the ground moves randomly in all directions, two horizontal directions (East-West (EW) direction, North-South (NS) direction) and one vertical direction (Up-Down (UD) direction). Even though extensive studies have been carried out on the earthquake-triggered landslide, the effects of each single seismic wave and the three-directional seismic waves are not considered. This study aims to evaluate the effects of different types of the seismic waves on the dynamic response and failure behavior of the high-steep rock slide. To investigate the effects of each single seismic wave and three-directional seismic wave, this study presents a numerical model with four types of seismic waves, e.g., East-West (EW) direction, North-South (NS) direction, Up-Down (UD) direction, and three-directional wave (EW_NS_UD). The numerical results revealed that the types of the seismic waves have significantly different effects on the dynamic process, failure behavior, run-out distance, velocity, and deposition of the high-steep rock slide.

scholarly journals Shaking Table Test of High Pier and Small Radius Curved Bridge under Multi-point Excitation

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Lei Yan ◽  
Guo Li ◽  
Kang An ◽  
Kefeng Yue ◽  
Zhi Lin
Keyword(s):  
Seismic Response ◽  
Seismic Waves ◽  
Shaking Table Test ◽  
Damping Ratio ◽  
Shaking Table ◽  
Small Radius ◽  
Curved Bridge ◽  
Bridge Model ◽  
High Pier ◽  
The Impact

The non-uniform stratum and uneven surface have the complicated seismic spatial variability. The seismic response of high pier and small radius curved bridge caused by the seismic specificity of this kind of terrain has not been systematically studied. According to the multi-point excitation theory of long-span structures and the similar theory of shaking table test in model structures, a high pier with small radius curved girder bridge was used as the research object. The shaking table test of real bridge model was carried out to study the seismic response laws of this kind of bridge under multi-point excitation. The results show that the designed seismic wave expansion device can meet the test requirements. The frequency of the model structure decreases rapidly and the damping ratio increases during the whole test process. The local terrain effect amplifies the seismic response of high pier and small radius curved bridge. The seismic response of high pier and small radius curved bridge is affected by different frequency spectrum seismic waves, and there is a big difference. Based on the above results, the impact of multi-point excitation should be considered in seismic design of high pier with small radius curved bridge.

scholarly journals Azimuth-, angle- and frequency-dependent seismic velocities of cracked rocks due to squirt flow

2019 ◽  
Author(s):  
Yury Alkhimenkov ◽  
Eva Caspari ◽  
Simon Lissa ◽  
Beatriz Quintal
Keyword(s):  
Seismic Wave ◽  
Seismic Waves ◽  
Numerical Study ◽  
Azimuth Angle ◽  
Hydrocarbon Exploration ◽  
Three Dimensions ◽  
Pore Scale ◽  
Frequency Dependent ◽  
Dependent Behavior ◽  
The Impact

Abstract. Understanding the properties of cracked rocks is of great importance in scenarios involving CO2 geological sequestration, nuclear waste disposal, geothermal energy, and hydrocarbon exploration and production. Developing non-invasive detecting and monitoring methods for such geological formations is crucial. Many studies show that seismic waves exhibit strong dispersion and attenuation across a broad frequency range due to fluid flow at the pore scale known as squirt flow. Nevertheless, how and to what extent squirt flow affects seismic waves is still a matter of investigation. To fully understand its angle- and frequency-dependent behavior for specific geometries appropriate numerical simulations are needed. We perform a three-dimensional numerical study of the fluid-solid deformation at the pore scale based on coupled Lame-Navier and Navier-Stokes linear quasistatic equations. We show that seismic wave velocities exhibit strong azimuth-, angle- and frequency-dependent behavior due to squirt flow between interconnected cracks. We show that the overall anisotropy of a medium mainly increases due to squirt flow but in some specific planes the anisotropy can locally decrease. We analyze the Thomsen-type anisotropic parameters and adopt another scalar parameter which can be used to measure the anisotropy strength of a model with any elastic symmetry. This work significantly clarifies the impact of squirt flow on seismic wave anisotropy in three dimensions and can potentially be used to improve the geophysical monitoring and surveying of fluid-filled cracked porous zones in the subsurface.

scholarly journals Study on Synthesis Method of Multipoint Seismic Waves for Buried Oil and Gas Pipeline in Shaking Table Tests

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Jian-Bo Dai ◽  
Gui-Di Zhang ◽  
Cheng-Tao Hu ◽  
Kai-Kai Cheng
Keyword(s):  
Seismic Wave ◽  
Seismic Waves ◽  
Oil And Gas ◽  
Shaking Table Test ◽  
Synthesis Method ◽  
Linear Structure ◽  
Gas Pipeline ◽  
Shaking Table ◽  
Infinite Length ◽  
Shaking Table Tests

The buried oil and gas pipeline is a linear structure with infinite length. In the shaking table test of its seismic response, it is necessary to input the spatially related multipoint seismic wave considering the propagation characteristics of ground motion. The multipoint seismic excitation shaking table tests and loading scheme of buried oil and gas pipelines are designed and formulated. The synthesis method of spatial correlation multipoint seismic wave for the buried oil and gas pipeline test is proposed in this study. The values of relevant parameters are analyzed, and corresponding program is compiled by MATLAB. The results show that the developed multipoint excitation shaking table seismic wave input scheme is reasonable. At the same time, the synthesized multipoint seismic wave based on the actual seismic record and artificial random simulation seismic wave can meet the test requirements, which suggests the testing effect is good.

The Influence of Pile-Pier Reinforcement Ratio on the Development of Plastic Zone of Bridge Structure

2013 ◽  
Vol 838-841 ◽  
pp. 1058-1062
Author(s):  
Bo Song ◽  
Kai Wen Li ◽  
Min Zhong
Keyword(s):  
Plastic Zone ◽  
Dynamic Response ◽  
Seismic Wave ◽  
Pile Foundation ◽  
Seismic Waves ◽  
Plate Boundary ◽  
Reinforcement Ratio ◽  
Bridge Structure ◽  
Nonlinear Seismic Response ◽  
Different Types

In this paper, using elastic-plastic fiber unit model for a continuous beam bridge structure and foundation to analyses the nonlinear seismic response of pier and pile foundation considering pile-soil interaction and the different types of seismic wave on the pile foundation and the pier dynamic response, focusing on the development of plastic zone and dynamic response of structure under different pile-pier reinforcement ration conditions. The results show that, with the pile pier reinforcement ratio increases, the response plasticity of pile and pier show a different trend; so pile-pier reinforcement ration is an important factor of dynamic characteristics for the bridge pier supported by group piles system; the pier reinforcement ratio not only impact on development of the plastic zone of the pier, but also impact on the pile. In addition, different types of seismic waves on the structure are different, the long-period seismic waves maximum, followed by inland direct seismic waves, plate boundary seismic wave minimum.

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