scholarly journals Shaking Table Test on the Response of a Cross Interchange Metro Station under Harmonic Excitations Refers to a Single Two-Storey Metro Station

2021 ◽  
Vol 11 (4) ◽  
pp. 1551
Author(s):  
Shiping Ge ◽  
Weifeng Wu ◽  
Wenqi Ding ◽  
Yong Yuan
Keyword(s):  
Large Scale ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Galvanized Steel ◽  
Seismic Excitations ◽  
Metro Station ◽  
Model Soil ◽  
Seismic Motion ◽  
Single Station ◽  
Parallel Tests

Interchange is essential in a metro network. Regarding the seismic performance, a series of large-scale shaking table tests were performed on an interchange station. The interchange station was composed of a two-story section rigidly connected to a perpendicular three-story section, leading to an abrupt change of stiffness in the conjunction area. Synthetic model soil (a mixture of sand and sawdust) and granular concrete with galvanized steel wires were used to model the soil–structure system. The seismic motion was input along the transversal direction of the two-story structure, including white noise and sinusoidal seismic excitations. Parallel tests of a single two-story station were correspondingly carried out as a contrast. Test data recorded by accelerometers and strain gauges are presented. The bending strains of the columns measured in the interchange station were found to be smaller than those in the single station. The concentration of the longitudinal strain was observed near the conjunction. Insights on the seismic response of the interchange station are provided.

Seismic Performance of Guideway Sliding Isolator with Gap Springs for Precision Machinery

2008 ◽  
Vol 11 (5) ◽  
pp. 511-524
Author(s):  
George C. Yao ◽  
Wen-Chun Huang ◽  
Fan-Ru Lin
Keyword(s):  
Shaking Table Test ◽  
Model Simulation ◽  
Shaking Table ◽  
Viscous Damping ◽  
Far Field ◽  
Seismic Excitations ◽  
Isolation System ◽  
Near Fault ◽  
Seismic Motion ◽  
Nonlinear Performance

The performance of gap springs in a guideway sliding isolator (GSI) system developed to protect precision machinery against seismic motion has been studied. A spring is initially distanced from the system by a gap, causing the isolation system to exhibit nonlinear performance once the gap is closed, reducing the chance of resonance. A full-scale shaking table test of a 22-ton specimen and a numerical model simulation in SAP2000 have been performed. The study shows that springs possessing the appropriate gaps are more effective in controlling relative displacements than is a pure friction system. The optimal gap for a system subjected to far-field earthquakes was found to be 5mm. In addition, supplemental viscous damping of less than 15% of the critical damping had no significant effect on the GSI system far-field seismic response, but it did reduce the relative displacements of the system for near-fault seismic excitations.

scholarly journals DEVELOPMENT OF A HIGH-SPEED VIDEOGRAMMETRIC MEASUREMENT SYSTEM WITH APPLICATION IN LARGE-SCALE SHAKING TABLE TEST

2019 ◽  
Vol IV-2/W7 ◽  
pp. 33-38
Author(s):  
S. Gao ◽  
Z. Ye ◽  
C. Wei ◽  
X. Liu ◽  
X. Tong
Keyword(s):  
Data Processing ◽  
Measurement System ◽  
High Speed ◽  
Large Scale ◽  
Moving Objects ◽  
Shaking Table Test ◽  
Image Sequences ◽  
Shaking Table ◽  
Dynamic Monitoring ◽  
Observation Network

<p><strong>Abstract.</strong> The high-speed videogrammetric measurement system, which provides a convenient way to capture three-dimensional (3D) dynamic response of moving objects, has been widely used in various applications due to its remarkable advantages including non-contact, flexibility and high precision. This paper presents a distributed high-speed videogrammetric measurement system suitable for monitoring of large-scale structures. The overall framework consists of hardware and software two parts, namely observation network construction and data processing. The core component of the observation network is high-speed cameras to provide multiview image sequences. The data processing part automatically obtains the 3D structural deformations of the key points from the captured image sequences. A distributed parallel processing framework is adopted to speed up the image sequence processing. An empirical experiment was conducted to measure the dynamics of a double-tube five-layer building structure on the shaking table using the presented videogrammetric measurement system. Compared with the high-accuracy total station measurement, the presented system can achieve a sub-millimeter level of coordinates discrepancy. The 3D deformation results demonstrate the potential of the non-contact high-speed videogrammetric measurement system in dynamic monitoring of large-scale shake table tests.</p>

scholarly journals Effect of Soil Box Boundary Conditions on Dynamic Behavior of Model Soil in 1 g Shaking Table Test

2020 ◽  
Vol 10 (13) ◽  
pp. 4642
Author(s):  
Hoyeon Kim ◽  
Daehyeon Kim ◽  
Yonghee Lee ◽  
Haksung Kim
Keyword(s):  
Boundary Conditions ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Boundary Effects ◽  
Soil Behavior ◽  
Ground Acceleration ◽  
Various Boundary Conditions ◽  
Model Soil ◽  
Shear Box ◽  
Laminar Shear

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.

Improvement of Laminar Shear Container for Shaking Table Test

2012 ◽  
Vol 588-589 ◽  
pp. 1889-1893
Author(s):  
Hai Feng Sun ◽  
Li Ping Jing ◽  
Qing Hai Wei ◽  
Xian Chun Meng
Keyword(s):  
Soil Structure ◽  
Shaking Table Test ◽  
Boundary Effect ◽  
Underground Structure ◽  
Dynamic Interaction ◽  
Shaking Table ◽  
Important Method ◽  
Model Soil ◽  
Structure Dynamic ◽  
Laminar Shear

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.

Study on Seismic Isolation and Hi-Frequency Vibration Isolation Technology for Equipment in Nuclear Power Plant Using Aero Floating Technique

2020 ◽  
Author(s):  
Kiyotaka Takito ◽  
Osamu Furuya ◽  
Hiroshi Kurabayashi ◽  
Kunio Sanpei
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Vibration Isolation ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Ground Surface ◽  
Shaking Table ◽  
Maximum Acceleration ◽  
Seismic Motion ◽  
Floating Base

Abstract In Japan, most structures on the ground surface need seismic countermeasures because of frequently earthquakes. On the other hand, vibration isolation devices are applied to precision or important equipment in several facilities that dislikes vibration in order to reduce daily vibration. In general, vibration isolation devices are intended for high frequency and small amplitude range. However, it is difficult to cut off both vibration region caused by flying object collision and seismic motion with existing technologies. The authors propose insulation of equipment and vibration transmitted through the floor by floating equipment, and have. We have devised and built an air floating device that operates when a trigger input is applied to save the energy of this dynamically acting device. It was estimated by numerical calculation that the aero floating device keeps lifting stably in the condition with the air pressure in the auxiliary air chamber about 75 to 80 kPa. The performance specifications of the proposed device were verified from shaking table test. As a result, the effect of reducing the maximum acceleration by about 1/5 against the seismic motion of El Centro NS, Taft NS, Tohoku NS, and Hachinohe EW was confirmed by floating the mass on the frame assuming the equipment. From the obtained power spectrum diagram (PSD) of the response acceleration, it was confirmed that all frequency components up to 25 Hz is reduced by using proposed aero floating base isolation device.

scholarly journals Seismic Response of a Bridge Pile Foundation during a Shaking Table Test

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Yunxiu Dong ◽  
Zhongju Feng ◽  
Jingbin He ◽  
Huiyun Chen ◽  
Guan Jiang ◽  
...  
Keyword(s):  
Seismic Wave ◽  
Pile Foundation ◽  
Large Scale ◽  
Amplification Factor ◽  
Shaking Table Test ◽  
Seismic Intensity ◽  
Shaking Table ◽  
Acceleration Amplification ◽  
Bedrock Surface ◽  
Bridge Pile Foundation

Puqian Bridge is located in a quake-prone area in an 8-degree seismic fortification intensity zone, and the design of the peak ground motion is the highest grade worldwide. Nevertheless, the seismic design of the pile foundation has not been evaluated with regard to earthquake damage and the seismic issues of the pile foundation are particularly noticeable. We conducted a large-scale shaking table test (STT) to determine the dynamic characteristic of the bridge pile foundation. An artificial mass model was used to determine the mechanism of the bridge pile-soil interaction, and the peak ground acceleration range of 0.15 g–0.60 g (g is gravity acceleration) was selected as the input seismic intensity. The results indicated that the peak acceleration decreased from the top to the bottom of the bridge pile and the acceleration amplification factor decreased with the increase in seismic intensity. When the seismic intensity is greater than 0.50 g, the acceleration amplification factor at the top of the pile stabilizes at 1.32. The bedrock surface had a relatively small influence on the amplification of the seismic wave, whereas the overburden had a marked influence on the amplification of the seismic wave and filtering effect. Damage to the pile foundation was observed at 0.50 g seismic intensity. When the seismic intensity was greater than 0.50 g, the fundamental frequency of the pile foundation decreased slowly and tended to stabilize at 0.87 Hz. The bending moment was larger at the junction of the pile and cap, the soft-hard soil interface, and the bedrock surface, where cracks easily occurred. These positions should be focused on during the design of pile foundations in meizoseismal areas.

Design Implications of Large-Scale Shaking Table Test on Four-Story Reinforced Concrete Building

2015 ◽  
Vol 112 (2) ◽  
Author(s):  
T. Nagae ◽  
W. M. Ghannoum ◽  
J. Kwon ◽  
K. Tahara ◽  
K. Fukuyama ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Reinforced Concrete Building ◽  
Concrete Building
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