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.

scholarly journals Research on Seismic Dynamic Response Characteristics of Weak Surrounding Rock Slope With Double-Arch Tunnel

2021 ◽  
Author(s):  
Xueliang Jiang ◽  
Yonghui Qian ◽  
Jiqi Zhang ◽  
Yong Liu ◽  
RiWe Deng ◽  
...  
Keyword(s):  
Seismic Wave ◽  
Amplification Factor ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Dynamic Displacement ◽  
Displacement Response ◽  
Response Characteristics ◽  
Acceleration Amplification ◽  
Dynamic Response Characteristics ◽  
Peak Value

Abstract Through the shaking table test, Wenchuan wave (WC) was used as the excitation wave of the shaking table test. The vibration was excited in three directions: horizontal (x), vertical (z), and horizontal and vertical (xz) and the dynamic response characteristics of rock slopes was studied. The results show:(1) The acceleration amplification factor of each measuring point of the slope shows a nonlinear increasing trend with the increase of the slope height.The slope changes the frequency spectrum of the loaded seismic wave.The slope has a filtering effect on the high frequency band of the seismic wave.(2) Under the unidirectional cyclic loading of Wenchuan wave, the slope acceleration amplification factor increases with the increase of the peak value of the seismic wave. Under the bi-directional excitation of Wenchuan wave, the slope acceleration amplification coefficient generally decreases with the increase of the peak value of the seismic wave.The slope acceleration amplification factor presents the characteristics of first increasing and then decreasing with the increase of the relative height of the slope.(3) The dynamic displacement response characteristics of the tunnel slope with double-arch tunnel are mainly affected by the seismic wave in the same direction and the peak value of the dynamic displacement response increases with the increase of the seismic wave peak value.(4) The peak dynamic displacement response of the double-arch tunnel slope shows a non-linear change trend with the increase of slope height. The dynamic displacement peak growth rate is slower below the rock interface and the dynamic displacement peak increases rapidly above the interface and Maximum displacement occurred at the top of the slope.

scholarly journals Large-Scale Shaking Table Test of Seismic Response Laws for a Shallow Double-Arch Tunnel under Unsymmetrical Pressure with a Damping Layer

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Hui Yang ◽  
Wang Zhou ◽  
Chan Liu ◽  
Xueliang Jiang ◽  
Lei Yu
Keyword(s):  
Large Scale ◽  
Amplification Factor ◽  
Shaking Table Test ◽  
Great Influence ◽  
Shaking Table ◽  
Dynamic Strain ◽  
Vertical Acceleration ◽  
Wave Excitation ◽  
Acceleration Response ◽  
The Right

Based on the similarity theory, a large-scale shaking table test of a shallow double-arch tunnel under unsymmetrical pressure with a similarity ratio of 1 : 20 was designed and completed, and a foam concrete damping layer was set in the double-arch tunnel. The acceleration response, strain response, and crack distribution of double-arch tunnels under different intensities and different directions of the Wenchuan wave excitation were studied (WC-X, WC-Z, and WC-XZ). The results showed that (1) the bias side (right hole) is greatly affected by the unevenness of the cover soil, and the horizontal acceleration response difference between the two tunnels is large and there is no symmetry. The incident direction of seismic waves has a great influence on the acceleration response of double-arch tunnels. The amplification factor of WC-Z is greater than that of WC-X. (2) On the same horizontal plane, with the vertical centerline of the middle wall as the axis of symmetry, the vertical acceleration amplification factor also has a large difference between the arch foot and the shoulder, but the difference is relatively small at other points. (3) The dynamic strain increases with the increase of seismic intensity, and the tendency is similar under the three different seismic wave excitation directions. The lining is under tensile strain and compressive strain, the strain of the left hole is greater than the strain of the right hole, and severe stress concentration occurs at the top left of the mid partition. (4) The middle partition, shoulder, and vault of the left hole and the shoulder, vault, and foot of the right hole are weak parts of earthquake resistance. Therefore, special attention should be paid to the seismic design.

scholarly journals Shaking Table Test On Dynamic Response of Bridge Pile Foundation Near Fault Under Strong Earthquake

2021 ◽  
Author(s):  
Cong Zhang ◽  
Zhong Ju Feng ◽  
Yuan Yuan Kong ◽  
Yun Hui Guan ◽  
Yun Xiu Dong ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Pile Foundation ◽  
Strong Earthquake ◽  
Shaking Table Test ◽  
Hanging Wall ◽  
Shaking Table ◽  
Wall Effect ◽  
Hanging Wall Effect ◽  
Bridge Pile Foundation

Abstract Taking Puqian bridge as the prototype, a 1:30-scale pile-soil-fault interaction model was established. Through the shaking table test, the difference of dynamic response of pile foundation on both sides of fault under 0.15~0.60g ground motion intensity was studied. The pile acceleration, pile top relative displacement, and pile bending moment on both sides of the fault are compared respectively. Research results showed that under the action of a strong earthquake, the pile foundation on the hanging wall was greatly affected by ground motion, and “the hanging wall effect” was significant. As the ground motion intensity increased, the “hanging wall effect” of the pile foundation was more obvious. Combined with the fundamental frequency response and the test phenomenon, when ground motions intensity was strong, cracks appeared near the joint of pile top and platform, soil interface, and bedrock surface. When building a bridge pile foundation near the fault, the seismic design of the pile foundation on the hanging wall of the fault is mainly considered.

scholarly journals Shaking Table Test on Dynamic Response of Bedding Rock Slopes With Weak Structural Plane Under Earthquake

2020 ◽  
Vol 8 ◽  
Author(s):  
Changwei Yang ◽  
Liang Zhang ◽  
Yang Liu ◽  
Denghang Tian ◽  
Xueyan Guo ◽  
...  
Keyword(s):  
Seismic Wave ◽  
Shaking Table Test ◽  
Surface Effect ◽  
Shear Plane ◽  
Shaking Table ◽  
Resonance Phenomenon ◽  
Amplification Coefficient ◽  
Structural Plane ◽  
Bedding Slope ◽  
Elevation Effect

Taking a bedding rock slope with weak structural plane as the prototype, a shaking table test with a similarity ratio of 1:10 is designed and carried out. By analyzing the acceleration and displacement responses at different positions of the slope, the seismic response and instability mechanism of rock bedding slope under different seismic amplitudes, frequencies, and durations are studied. Before the failure of the slope, the rock bedding slope shows an obvious “elevation effect” and “surface effect” under the action of Wenchuan Wolong earthquake wave with different amplitudes. With the increase of the amplitude of the input seismic wave, the elevation effect and the surface effect gradually weaken. When the amplitude of the seismic wave reaches 0.9 g, the rock bedding slope begins to show damage, which demonstrates that the difference of PGA amplification coefficients on both sides of the weak structural plane increases significantly. Compared with the Kobe seismic wave and Wenchuan Wolong seismic wave, the excellent frequency of EL Centro seismic wave is closer to the first-order natural frequency of slope model and produces resonance phenomenon, which leads to the elevation effect of PGA amplification coefficient more significantly. Through the analysis of the instability process of rock bedding slope, it can be found that the failure mechanism of the slope can be divided into two stages: the formation of sliding shear plane and the overall instability of the slope.

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>

Study on Lateral Dynamic Response of Pile Foundation in Liquefiable Soil by Using FBG Method

2012 ◽  
Vol 238 ◽  
pp. 337-340 ◽  
Author(s):  
Yu Run Li ◽  
Yan Liang ◽  
Xing Wei ◽  
Yun Long Wang ◽  
Zhen Zhong Cao
Keyword(s):  
Dynamic Response ◽  
Data Acquisition ◽  
Pile Foundation ◽  
Maximum Stress ◽  
Shaking Table Test ◽  
Data Acquisition System ◽  
Seismic Damage ◽  
Shaking Table ◽  
Calculation Methods ◽  
Liquefiable Soil

The study on lateral dynamic response of pile foundation in liquefiable soil is a significant part about seismic damage. In this paper, a new data acquisition system of FBG and calculation methods is used in the small shaking table test. The results show that FBG method used in this test is proved to be efficient and acceptable in both time characteristics and precision characteristics, it may be widely applied in the future doubtlessly. What’s more, the characteristics of p-y curves in different peak accelerations are discussed. And varying of maximum stress and displacement by corresponding acceleration is discussed. A contrast about p-y curve between dry sand and saturate sand is related, which provides a new direction in research about p-y curve.

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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