scholarly journals Design and Performance of a Single Axis Shake Table and a Laminar Soil Container

2018 ◽  
Vol 4 (6) ◽  
pp. 1326 ◽  
Author(s):  
Reza Alaie ◽  
Reza Jamshidi Chenari

Correct evaluation of shear modulus and damping characteristics in soils under dynamic loading is one of the most important topics in geotechnical engineering. Shaking tables are used for physical modelling in earthquake geotechnical engineering and is key to the fundamental understanding and practical application of soil behaviour. The shaking table test is realistic and clear when the response of geotechnical problems such as liquefaction, post-earthquake settlement, foundation response and soil-structure interaction and lateral earth pressure problems, during an earthquake is discussed. This paper describes various components of the uniaxial shaking table at university of Guilan, Iran. Also, the construction of the laminar shear box is described. A laminar shear box is a flexible container that can be placed on a shaking table to simulate vertical shear-wave propagation during earthquakes through a soil layer of finite thickness. Typical model tests on sandy soil conducted on the shaking table and the results obtained are also presented. Appropriate evaluation of shear modulus and damping characteristics of soils subjected to dynamic loading is key to accurate seismic response analysis and soil modelling programs. The estimated modulus reduction and damping ratio were compared to with Seed and Idriss’s benchmark curves.

2020 ◽  
Vol 10 (13) ◽  
pp. 4642
Author(s):  
Hoyeon Kim ◽  
Daehyeon Kim ◽  
Yonghee Lee ◽  
Haksung Kim

In order to evaluate the effects of soil box boundary conditions on the dynamic soil behavior, the Rigid Box (RB) and the Laminar Shear box (LSB) were constructed and 1 g shaking table tests were carried out for various boundary conditions. The boundary effects of the RB and the LSB were compared. To reduce the boundary effects of the RB, sponges, 5 cm, 10 cm, and 15 cm in thickness, were attached to the two end sides of the RB. A model soil was constructed on flat ground, and the acceleration and amplification occurring in the center of the soil were analyzed by spectrum and peak ground acceleration. Compared with the RB, the center and wall accelerations of LSB were very close to each other. This implies that the LSB can better simulate the behavior of the infinite half space than the RB.


Author(s):  
Akihiko UCHIDA ◽  
Junji HAMADA ◽  
Tomio TSUCHIYA ◽  
Kiyoshi YAMASHITA ◽  
Masaaki KAKURAI

2021 ◽  
Vol 11 (4) ◽  
pp. 1875
Author(s):  
Yong Jin ◽  
Hoyeon Kim ◽  
Daehyeon Kim ◽  
Yonghee Lee ◽  
Haksung Kim

In order to verify the reliability of numerical analysis, a series of 1 g shaking table tests for flat ground and slope were conducted using a laminar shear box subjected to different seismic waves. Firstly, numerical analyses, using the DEEPSOIL and ABAQUS software, were done to compare the results of flat ground experiments. After that, finite element analyses with ABAQUS were conducted to compare the results of slope experiments. For numerical analyses, considering the influence of the boundary, the concept of adjusted elastic modulus was proposed to improve the simulation results. Based on the analyses, it is found that in terms of acceleration-time history and spectral acceleration, the numerical analysis results are in good agreement with the experiment results. This implies that numerical analysis can capture the dynamic behavior of soil under 1 g shaking table test conditions.


2001 ◽  
Vol 1 (2) ◽  
pp. 43-51
Author(s):  
Tomio Tsuchiya ◽  
Masaaki Kakurai ◽  
Kiyoshi Yamashita ◽  
Junji Hamada

2019 ◽  
Vol 7 (6) ◽  
pp. 189 ◽  
Author(s):  
Linya Chen ◽  
Dong-Sheng Jeng ◽  
Chencong Liao ◽  
Dagui Tong

Cofferdams are frequently used to assist in the construction of offshore structures that are built on a natural non-homogeneous anisotropic seabed. In this study, a three-dimensional (3D) integrated numerical model consisting of a wave submodel and seabed submodel was adopted to investigate the wave–structure–seabed interaction. Reynolds-Averaged Navier–Stokes (RANS) equations were employed to simulate the wave-induced fluid motion and Biot’s poroelastic theory was adopted to control the wave-induced seabed response. The present model was validated with available laboratory experimental data and previous analytical results. The hydrodynamic process and seabed response around the dumbbell cofferdam are discussed in detail, with particular attention paid to the influence of the depth functions of the permeability K i and shear modulus G j . Numerical results indicate that to avoid the misestimation of the liquefaction depth, a steady-state analysis should be carried out prior to the transient seabed response analysis to first determine the equilibrium state caused by seabed consolidation. The depth function G j markedly affects the vertical distribution of the pore pressure and the seabed liquefaction around the dumbbell cofferdam. The depth function K i has a mild effect on the vertical distribution of the pore pressure within a coarse sand seabed, with the influence concentrated in the range defined by 0.1 times the seabed thickness above and below the embedded depth. The depth function K i has little effect on seabed liquefaction. In addition, the traditional assumption that treats the seabed parameters as constants may result in the overestimation of the seabed liquefaction depth and the liquefaction area around the cofferdam will be miscalculated if consolidation is not considered. Moreover, parametric studies reveal that the shear modulus at the seabed surface G z 0 has a significant influence on the vertical distribution of the pore pressure. However, the effect of the permeability at the seabed surface K z 0 on the vertical distribution of the pore pressure is mainly concentrated on the seabed above the embedded depth in front and to the side of the cofferdam. Furthermore, the amplitude of pore pressure decreases as Poisson’s ratio μ s increases.


2012 ◽  
Vol 588-589 ◽  
pp. 1889-1893
Author(s):  
Hai Feng Sun ◽  
Li Ping Jing ◽  
Qing Hai Wei ◽  
Xian Chun Meng

Shaking table test is an important method to study on the problem of the soil-structure dynamic interaction. The property of the soil container directly affects the accuracy of the result. A laminar shear container was designed for shaking table test. And a shaking table test on soil-underground structure dynamic interaction which structure lay in clay was conducted. The results of the test show that the container eliminated the boundary effect when the dynamic load was applied in only one horizontal direction. Meanwhile, the stiffness of the soil container could be changed according to the change of the model soil, which is applicable to decrease the boundary effect.


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