Seismic Behaviour of Geosynthetic-Reinforced Slopes with Overload by Shaking Table Tests

Author(s):  
A. S. Lo Grasso ◽  
M. Maugeri ◽  
P. Recalcati
2020 ◽  
Vol 14 (03) ◽  
pp. 2050011
Author(s):  
Lin Zhou ◽  
Guangya Ding ◽  
Jie Tan ◽  
Xiaoxia Zhao ◽  
Jun Wang

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.


2019 ◽  
Vol 92 ◽  
pp. 17002
Author(s):  
Zitao Zhang ◽  
Jianzhang Xiao ◽  
Yingqi Wei ◽  
Hong Cai ◽  
Jianhui Liang ◽  
...  

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuai Huang ◽  
Qingjie Qi ◽  
Shufeng Zhai ◽  
Wengang Liu ◽  
Jianzhong Liu

AbstractIce-structure interaction threatens the safety of the offshore structure; however, dynamic seismic action even renders this process more sophisticated. This research constructed a simplified calculation model for the wind turbine tower, ice, and water under seismic loading, which could avoid solving the complex non-linear equations. Then, the seismic behaviour of the structure, i.e. wind turbine tower, in the presence and absence of influences of the sea ice was investigated, and we found the remarkable effect of sea ice upon the wind turbine tower when its mass is within a range; the wind turbine tower is found to have reduced capacity in energy dissipation, and thickness of tower walls or stiffening ribs is supposed to be enlarged for making the structure more ductile. Affected by the sea ice, the shear force and bending moment of the tower showed significant increases, and more attention needs to be paid to the tower bottom and action position of the sea ice. According to the dynamic similarity principle, finally paraffin was used to simulate sea ice, and shaking-table tests were performed for simulating dynamic ice-structure-water interactions. Results of shaking-table tests verified the rationality of our proposed simplified model.


2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 233-240
Author(s):  
Junaid Akbar ◽  
Naveed Ahmad ◽  
Bashir Alam

Shaking table tests were performed on five one-third reduced scale two storey reinforced concrete (RC) moment resisting frames having construction defects (using low strength concrete without confining ties in beam-column joints, larger tie spacing, and reduced longitudinal and transverse reinforcements). The deficient frames were observed to have severe joint damageability, resulting in joint panel cover spalling and core concrete crushing. Haunch retrofitting technique was adopted to upgrade the seismic behaviour of deficient RC frames. Additional four deficient RC frames were built and retrofitted with steel haunch; both axially stiffer and deformable with energy dissipation, fixed to the beam-column connections to reduce shear demand on joint panels. The as-built and retrofitted frame seismic response modification factor (R) was calculated and compared to evaluate the viability of the haunch retrofitting technique. The haunch retrofitting technique increased the lateral stiffness and strength of the structure, resulting in the increase of structure overstrength. The retrofitting increased R factor by sixty percent to one hundred percent. The presented results indicate that the technique can significantly enhance the seismic performance of deficient RC frames, particularly against the frequent and rare earthquake events.


Structures ◽  
2021 ◽  
Vol 33 ◽  
pp. 2990-3001
Author(s):  
Yang Yang ◽  
Weiming Gong ◽  
Yi Pik Cheng ◽  
Guoliang Dai ◽  
Yuwan Zou ◽  
...  

2021 ◽  
Vol 18 (9) ◽  
pp. 2460-2474
Author(s):  
Zhi-jia Wang ◽  
Gang Fan ◽  
Li-cong Cao ◽  
Jin-yuan Chang

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