scholarly journals Shaking-Table Tests for Immersed Tunnels at Different Sites

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Xinjun Cheng ◽  
Liping Jing ◽  
Jie Cui ◽  
Yongqiang Li ◽  
Rui Dong
Keyword(s):  
Seismic Waves ◽  
Water Layer ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Saturated Sand ◽  
Shaking Table Tests ◽  
Seismic Responses ◽  
Overlying Water ◽  
Immersed Tunnel ◽  
Soil Deposits

Immersed tunnels are typically built in areas subjected to ground motion. Therefore, an evaluation of the seismic performance of the soil-tunnel system is essential. A series of shaking-table tests was conducted to study the influences of the site soil and overlying water layer on the seismic responses of soil deposits and an immersed tunnel. Detailed information on the experiment setup is provided with special focus on the similitude relationship, fabrication of the model system, measurement setup, and loading procedures for a simulation of the seismic waves. Three groups of tests at different sites in dry sand, saturated sand, and saturated sand with an overlying water layer were carried out using the same seismic excitations. The seismic responses of the soil deposits and the dynamic responses of the tunnel model were obtained. The experiment results indicate that, when considering only horizontal earthquake excitations, soil liquefaction significantly influences the propagation of seismic waves and the dynamic responses of the tunnel, whereas the water layer has no obvious effects on the dynamic performance of the ground or tunnel. Furthermore, the acceleration responses of the tunnel elements were analyzed qualitatively, and the joints are deemed important elements in an antiseismic immersed tunnel design.

Shaking-table tests of seismic responses of slender intake tower-hoist chamber systems

2021 ◽  
Vol 242 ◽  
pp. 112517
Author(s):  
Hanyun Zhang ◽  
Cai Jiang ◽  
Shuming Liu ◽  
Liaojun Zhang ◽  
Chen Wang ◽  
...  
Keyword(s):  
Shaking Table ◽  
Shaking Table Tests ◽  
Seismic Responses

Shaking table tests on the seismic responses of underground structures in coral sand

2021 ◽  
Vol 109 ◽  
pp. 103775
Author(s):  
Xuanming Ding ◽  
Yanling Zhang ◽  
Qi Wu ◽  
Zhixiong Chen ◽  
Chenglong Wang
Keyword(s):  
Shaking Table ◽  
Shaking Table Tests ◽  
Seismic Responses ◽  
Underground Structures ◽  
Coral Sand

Experimental Study on Vertical Base-Isolated System with Disk Spring

2012 ◽  
Vol 166-169 ◽  
pp. 788-792
Author(s):  
Yamin Zhao ◽  
Jingyu Su ◽  
Ming Lu
Keyword(s):  
Shaking Table ◽  
Base System ◽  
Performance Tests ◽  
Shaking Table Tests ◽  
Seismic Responses ◽  
Vertical Stiffness ◽  
Disk Spring ◽  
Fixed Base ◽  
Structural Responses ◽  
Vertical Base

A new vertical isolator designed by disk spring, called combined disk spring bearing (DSB), is introduced in this paper. DSB is composed of one main disk spring bearing and eight secondary disk spring bearings. Performance tests show that DSB had good property of variable vertical stiffness and high vertical damping. Then, the effectiveness of DSB vertical base-isolated devices in reducing structural responses caused by earthquakes through a series of 1/2 scale shaking table tests. are conducted to study the seismic responses of the and the DSB vertical-isolated system. Compared with the fixed-base system, experimental results show that the DSB vertical-isolated system can isolate vertical earthquake energy remarkably. Large displacement of the DSB vertical-isolated system occurred on the isolation layer, and the inter-story deformation of the superstructure changed slightly. The acceleration responses of DSB vertical-isolated system decreased more than 50% and the displacement responses decreased more than 40% at 0.4g PGA, which confirmed that DSB could decrease the seismic responses effectively.

scholarly journals Seismic Response of Aeolian Sand High Embankment Slopes in Shaking Table Tests

2019 ◽  
Vol 9 (8) ◽  
pp. 1677 ◽  
Author(s):  
Zhijun Zhou ◽  
Jiangtao Lei ◽  
Shaobo Shi ◽  
Tong Liu
Keyword(s):  
Seismic Waves ◽  
Shear Failure ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Aeolian Sand ◽  
Distribution Law ◽  
Horizontal Acceleration ◽  
Reflected Wave ◽  
Increasing Trend ◽  
Three Stages

Aeolian sand high embankments are always damaged by earthquakes; however, little research has addressed this so far. In this study, shaking table tests were conducted on three aeolian sand high embankment models. Based on the shear failure mechanism of aeolian sand, the seismic responses of model embankments were analyzed. When seismic waves were inputted, the horizontal acceleration magnification (HAM) of three models always exceeded 1.0, and showed an increasing trend with height. Furthermore, according to the HAM change rules of three models under different input peak accelerations, the destruction of model embankments under earthquakes includes three stages: the reflected wave emergence (RWE) stage, the reflected wave strengthening (RWS) stage, and the acceleration magnification attenuation (AMA) stage. According to this definition, models with slopes of 1/1.2 and 1/0.8 experienced all three stages during tests, and the critical horizontal acceleration transform from the RWS stage to the AMA stage appeared. The model with a slope of 1/1.5 only experienced RWE and RWS stages during the test. At the end of the tests, the macroscopic instability mechanisms of all three models were studied, which were found to match the distribution law of HAM during tests and the destruction stage definition.

scholarly journals Examining the seismic behaviour of partially saturated sand using centrifuge shaking table tests

2019 ◽  
Vol 92 ◽  
pp. 17002
Author(s):  
Zitao Zhang ◽  
Jianzhang Xiao ◽  
Yingqi Wei ◽  
Hong Cai ◽  
Jianhui Liang ◽  
...  
Keyword(s):  
Effective Stress ◽  
Experimental Results ◽  
Shaking Table ◽  
Degree Of Saturation ◽  
Saturated Sand ◽  
Shaking Table Tests ◽  
Seismic Behaviour ◽  
Liquefaction Resistance ◽  
Partially Saturated ◽  
Partially Saturated Sand

Similar to fully saturated sand, the partially saturated sand can also liquefy under certain conditions during earthquakes. This study aims to characterize the seismic behaviour of partially saturated sand. Centrifuge shaking table tests were performed using the IWHR horizontal-vertical centrifuge shaker. The experimental results indicate that the liquefaction resistance of the partially saturated sand increases with decreasing the degree of saturation and with increasing the initial effective stress right before shaking. The boundary between the liquefied and un-liquefied sand becomes deeper and deeper during shaking.

Experimental Study of a Multiple Bay Structure Isolated With Hybrid Bearings

2003 ◽  
Author(s):  
C. S. Tsai ◽  
Bo-Jen Chen ◽  
Tsu-Cheng Chiang ◽  
Guan-Hsing Lee
Keyword(s):  
Earthquake Engineering ◽  
Base Isolation ◽  
Steel Structure ◽  
Seismic Energy ◽  
Shaking Table ◽  
Element Formulation ◽  
Shaking Table Tests ◽  
Seismic Responses ◽  
Promising Tool ◽  
Rubber Bearings

In conventional earthquake resistance design approach (the ductility-design philosophy), the energy dissipation mechanism is based on plastic deformations at scattered locations in the structure. However, this can produce permanent damage to the joints as well as the larger interstory displacements. In recently years, the base isolation technology has been adopted as a feasible and attractive way in improving seismic resistance of structures. It can shift the natural periods of structures away from the rich periods contents of earthquake motions, but also provide considerable supplemental damping to dissipate seismic energy transmitted into structures during earthquakes. In this paper, uniaxial, biaxial, and triaxial shaking table tests are performed to study the seismic behavior of a 0.4-scale three-story isolated steel structure in the National Center for Research on Earthquake Engineering in Taiwan. Experimental results demonstrate that structures with hybrid rubber bearings can actually decrease the seismic responses of the superstructure. It has been proved through the shaking table tests that the rubber bearing is a very promising tool to enhance the seismic resistibility of structures. Moreover, it is illustrated that the proposed analytical model and finite element formulation in this paper can well predict the mechanical behavior of rubber bearings and seismic responses of the base-isolated structures.

scholarly journals Compaction and Liquefaction of a Sandy Layer: Simulation of Shaking Table Experiments

2013 ◽  
Vol 59 (4) ◽  
pp. 509-521 ◽  
Author(s):  
A. Sawicki ◽  
W. Świdziński
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Shaking Table ◽  
Sand Layer ◽  
Saturated Sand ◽  
Shaking Table Tests ◽  
Horizontal Acceleration ◽  
Sandy Layer ◽  
Dry Sand ◽  
Model C

AbstractThis paper presents numerical simulations of the behavior of a sandy layer subjected to a cyclic horizontal acceleration in shaking table tests, with a particular attention focused on the settlements of a dry sand layer, and on the liquefaction of saturated sand. A compaction/liquefaction model (C/L) is applied to these simulations. The influence of specific parameters of the model on the compaction and liquefaction of a sandy layer is shown and discussed. The results of simulations are compared with selected experimental data.

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