Shaking Table Tests and Numerical Analysis on the Seismic Response of Karst-Crossing Socketed Piles in Dry Sandy Soil Foundation

The foundation piles in karst areas have different mechanical properties from those in other areas. Targeting a critical highway bridge in a karst area, this paper designs two kinds of foundation pile models: friction pile, and KCSP, based on theories on dynamic tests. Then, shaking table tests were carried out to ascertain the features of pile strain distribution of KCSP under earthquakes. During the tests, a large laminar suspended shear box was adopted to mimic the boundary effect of soil. In addition, numerical simulations were conducted to disclose the effects of karst cave on pile strain. The test results indicate that: the peak strain of KCSP increased with the peak acceleration; For both KCSP and friction pile, the peak strain decreased first and then increased along the depth; The presence of karst cave can adversely affect the seismic response of foundation pile; The taller the karst cave, the larger the peak strain of the pile; the peak strain of KCSP was larger at the two ends, and smaller in the middle. The numerical analysis shows that: the peak strain of foundation pile in karst cave increased significantly with cave height; The peak strain of the pile passing through multiple caves was similar to that of the pile passing through only one cave, under the same cave height; But the multi-cave scenario differed from the single-cave scenario in peak strain distribution. The research results provide new insights into the seismic design of pile foundation of bridges in karst areas.

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Seismic Response of Concrete-Canvas Reinforced Slopes: Influence of Tilt Degrees for Reinforcement

Journal of Earthquake and Tsunami ◽

10.1142/s1793431120500116 ◽

2020 ◽

Vol 14 (03) ◽

pp. 2050011

Author(s):

Lin Zhou ◽

Guangya Ding ◽

Jie Tan ◽

Xiaoxia Zhao ◽

Jun Wang

Keyword(s):

Seismic Response ◽

Threshold Level ◽

Shaking Table ◽

Shaking Table Tests ◽

Slope Surface ◽

Reinforcing Effect ◽

Failure Patterns ◽

Coral Sand ◽

Before And After ◽

Reinforced Slopes

A series of shaking table tests were conducted on reinforced slopes to study the slope dynamic characteristics. The influence of concrete-canvas tilt degrees on the seismic response was studied. By considering the effects of different concrete-canvas tilt degrees, the seismic responses of the reinforced slopes were analyzed, along with the accelerations, crest settlements, and horizontal displacements. The failure patterns of different model slopes were compared using white coral sand marks placed at designated elevations to monitor the internal slide of the reinforced slopes. Several round markers were placed on the slope surface to compare the deformation before and after shaking with different amplitudes. The results indicated that with the increase in concrete-canvas tilt degrees, a better reinforcing effect was obtained, and 30° reinforcement reached a threshold level, the slide-out point shifts from the crest of the slope to the middle of the reinforced model. The bottom 2/7th zone of the slope was relatively stable during the earthquake and the reinforcement was ineffective at the bottom of the slope. When both considered the influence of reinforcing effect and construction difficulty, 20° is the suitable tilt degree in concrete-canvas reinforced slopes. The characteristics of increasing strength of the concrete canvas make it suitable for the application in slope protection.

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SHAKING TABLE TESTS ON SEISMIC RESPONSE OF ISOLATORS FOR HOUSES(Structures)

AIJ Journal of Technology and Design ◽

10.3130/aijt.9.35 ◽

2003 ◽

Vol 9 (18) ◽

pp. 35-40

Author(s):

Mitsumasa MIDORIKAWA ◽

Masanori IIBA

Keyword(s):

Seismic Response ◽

Shaking Table ◽

Shaking Table Tests

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Seismic Response Estimation of Water Extinguishing Facilities using Shaking Table Tests

Journal of the Earthquake Engineering Society of Korea ◽

10.5000/eesk.2012.16.4.009 ◽

2012 ◽

Vol 16 (4) ◽

pp. 9-18 ◽

Cited By ~ 1

Author(s):

Min-Jun Nam ◽

Seung-Hee Park ◽

Dong-Joon Kim ◽

Jun-Sung Choi

Keyword(s):

Seismic Response ◽

Shaking Table ◽

Shaking Table Tests

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Shaking Table Tests Examining Seismic Response of Suspended Ceilings Attached to Large-Span Spatial Structures

Journal of Structural Engineering ◽

10.1061/(asce)st.1943-541x.0002140 ◽

2018 ◽

Vol 144 (9) ◽

pp. 04018152 ◽

Cited By ~ 4

Author(s):

Yan Lu ◽

Gilberto Mosqueda ◽

Qinghua Han ◽

Yifeng Zhao

Keyword(s):

Seismic Response ◽

Shaking Table ◽

Spatial Structures ◽

Shaking Table Tests ◽

Large Span

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Seismic Response of Soil Slopes in Shaking Table Tests: Effect of Type and Quantity of Reinforcement

International Journal of Geosynthetics and Ground Engineering ◽

10.1007/s40891-016-0074-2 ◽

2016 ◽

Vol 2 (4) ◽

Cited By ~ 12

Author(s):

N. Srilatha ◽

G. Madhavi Latha ◽

C. G. Puttappa

Keyword(s):

Seismic Response ◽

Shaking Table ◽

Shaking Table Tests ◽

Soil Slopes

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Experimental Study on the Seismic Response of Subway Station in Soft Ground

Journal of Earthquake and Tsunami ◽

10.1142/s1793431117500208 ◽

2017 ◽

Vol 11 (05) ◽

pp. 1750020 ◽

Cited By ~ 4

Author(s):

Ma Xianfeng ◽

Wang Guobo ◽

Wu Jun ◽

Ji Qianqian

Keyword(s):

Seismic Response ◽

Seismic Design ◽

Shaking Table Test ◽

Design Method ◽

Underground Structure ◽

Response Characteristic ◽

Shaking Table ◽

Subway Station ◽

Soft Ground ◽

Shaking Table Tests

Shaking table tests were conducted on typical models of subway structures subjected to several seismic shaking time histories to study seismic response of subway structures in soft ground as well as to provide data for validation of seismic design methods for underground structure. Three types of tests were presented herein, namely green field test, subway station test, and test for joint structure between subway station and tunnel. The similitude and modeling aspects of the 1g shaking table test are discussed. The seismic response of Shanghai clay in different depths was examined under different input waves to understand the acceleration amplification feature in both green field and in the presence of underground structure. Damage situation was checked on internal sections of both subway station and tunnels by halving the model structure. Structure deformation was investigated in terms of element strain under different earthquake loadings. The findings from this study provides useful pointers for future shaking table tests on underground structures/facilities, and the seismic response characteristic of underground structure derived from the shaking table test could be helpful for validating seismic design method for subway station.

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

Advances in Civil Engineering ◽

10.1155/2021/6633535 ◽

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.

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