scholarly journals Seismic Responses of GRS Walls with Secondary Reinforcements Subjected to Earthquake Loading

2020 ◽  
Vol 10 (20) ◽  
pp. 7084
Author(s):  
Chih-Hsuan Liu ◽  
Ching Hung
Keyword(s):  
Large Scale ◽  
Numerical Procedure ◽  
Secondary Reinforcement ◽  
Reinforced Soil ◽  
Primary Reinforcement ◽  
Shaking Table ◽  
Seismic Responses ◽  
Geosynthetic Reinforced Soil ◽  
Acceleration Amplification ◽  
Vertical Spacing

Secondary reinforcement has been proven to be effective in increasing the performance of geosynthetic-reinforced soil (GRS) walls under working stress conditions, enabling an eco-friendlier environment. However, the seismic responses of GRS walls with secondary reinforcements are still unclear. In this study, in-depth finite element analyses were used to investigate the seismic responses of GRS walls with secondary reinforcement subjected to earthquake motions. The numerical procedure was first validated using measurements obtained from both a field GRS wall with secondary reinforcement and benchmark large-scale shaking table tests. Then, the validated GRS walls procedure was utilized to explore the effects of secondary reinforcement length and stiffness, the vertical spacing of the primary reinforcement, and wall height on the seismic responses. Based on the study, the following findings can be drawn: (i) the secondary reinforcement length and stiffness under various wall heights and peak ground accelerations (PGAs) have a limited influence on the relative lateral facing displacement and acceleration amplification, however, they can significantly decrease the connection load and the maximum reinforcement load; (ii) increasing the length of the secondary reinforcement is more effective for reducing the connection load and the maximum reinforcement load than increasing the stiffness of the secondary reinforcement; (iii) the effect of secondary reinforcement is more evident for greater wall height, the larger vertical spacing of primary reinforcement, and smaller PGA; and (iv) GRS walls with secondary reinforcement could ease the acceleration amplification. The study has highlighted the salient effect of secondary reinforcement on GRS wall performance under seismic conditions.

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 Shaking Table Study on the Seismic Performance of Geogrid Reinforced Soil Retaining Walls

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xiaoguang Cai ◽  
Sihan Li ◽  
Honglu Xu ◽  
Liping Jing ◽  
Xin Huang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Fundamental Frequency ◽  
Retaining Wall ◽  
Failure Surface ◽  
Reinforced Soil ◽  
Shaking Table ◽  
Seismic Load ◽  
Peak Displacement ◽  
Acceleration Amplification ◽  
Reinforcement Strain

This study presents experimental results from shaking table tests on a reduced-scale geogrid reinforced soil retaining wall (RSRW) to investigate the seismic response of the fundamental frequency, acceleration amplification, face displacement, backfill surface settlement, and reinforcement strain under different peak accelerations and durations. The fundamental frequency is in good agreement with the predicted values. The root mean square (RMS) acceleration amplification factors increase nonlinearly with the wall height and decrease with increasing seismic load, which is not regarded as a constant value. The distributions of the peak displacement are consistent with those of the residual displacement. The combination of the sliding and rotation is observed as the predominant mode of displacement, and the rotation mode is dominant. The positions near the face (35 cm) and the ends of the reinforcement (140 cm) demonstrated larger settlement than that of the central position (70 cm and 105 cm). The reinforcement strain increased with increasing peak acceleration and maximum values measured at the central layers. The trends of the potential failure surface are similar to those of the 0.3H bilinear failure surface. The friction coefficient is nonlinearly distributed along with the reinforcements, and the maximum friction coefficient appears at the top layer (F11).

scholarly journals Resistance of Laminar Drain Reinforcement Levee against Overflow Erosion

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1768 ◽  
Author(s):  
Yuki Kurakami ◽  
Yasuo Nihei
Keyword(s):  
Large Scale ◽  
Model Tests ◽  
Reinforced Soil ◽  
Scale Model ◽  
Concrete Panels ◽  
Geosynthetic Reinforced Soil ◽  
Levee Failure ◽  
Large Scale Model ◽  
The Times ◽  
Soil Levee

As a method for reinforcing against overflow erosion and infiltration, this study investigated a laminar drain reinforcement (LDR) levee, in which the drain layers are set on the back slope and connected to concrete panels using geogrid layers. We examined the resistance against overflow erosion of the LDR levee by large-scale model tests with a 1 m high model levee. We also compared the resistance of an armored levee, which is covered with concrete panels, and a GRS (geosynthetic-reinforced soil) levee, in which the geogrid layers are laid in the levee body with connecting concrete panels. The results of the model tests reveal that: (1) the LDR levee can maintain the initial height and shape for more than 150 min; by comparison, the times to levee failure were 87 and 102 min for the armored and GRS levees, respectively; (2) the LDR levee was shown to have a highly tenacious structure offering resistance to overflow erosion. In particular, panels easily flowed out with a slight gap (less than 1 cm) for the armored levee, while the LDR levee was able to prevent flowing out of panels and the erosion of the levee body, thanks to the laminar drain at the back slope, even when the gaps between the surface panels exceeded 5 cm.

scholarly journals Performance of Geosynthetic-Reinforced Soils Under Static and Cyclic Loading

2017 ◽  
Vol 7 (2) ◽  
pp. 1523-1527 ◽  
Author(s):  
M. Touahmia
Keyword(s):  
Cyclic Loading ◽  
Large Scale ◽  
Soil Mass ◽  
Reinforced Soil ◽  
Geosynthetic Reinforcement ◽  
Great Resistance ◽  
Geosynthetic Reinforced Soil ◽  
Confining Pressures ◽  
Pullout Failure ◽  
Static And Cyclic Loading

This paper investigates and discusses the composite behavior of geosynthetic reinforced soil mass. It presents the results of a series of large-scale laboratory tests supported by analytical methods to examine the performance of geogrid reinforcement subjected to static and cyclic pullout loading. The testing equipment and procedures used for this investigation are outlined. The results show that geosynthetic reinforcement can mobilize great resistance to static pulling load under high confining pressures. The reinforcement exhibits gradual deformation under cyclic loading showing no sign of imminent pullout failure for all levels of applied loads. In general, the results demonstrate that geosynthetic can be used in situations where loads are non-static, although care will be required in ensuring that appropriate factors of safety are applied to control the resulting deformation. A simplified analytical model for calculating the pulling capacity of geosynthetic reinforcement is proposed.

Seismic responses of deep buried pipeline under non-uniform excitations from large scale shaking table test

2018 ◽  
Vol 113 ◽  
pp. 180-192 ◽  
Author(s):  
Kongming Yan ◽  
Jianjing Zhang ◽  
Zhijia Wang ◽  
Weiming Liao ◽  
Zuoju Wu
Keyword(s):  
Large Scale ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Buried Pipeline ◽  
Seismic Responses

Large-Scale Shaking Table Tests on Modular-Block Reinforced Soil Retaining Walls

2005 ◽  
Vol 131 (4) ◽  
pp. 465-476 ◽  
Author(s):  
Hoe I. Ling ◽  
Yoshiyuki Mohri ◽  
Dov Leshchinsky ◽  
Christopher Burke ◽  
Kenichi Matsushima ◽  
...  
Keyword(s):  
Large Scale ◽  
Retaining Walls ◽  
Reinforced Soil ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Soil Retaining Walls

scholarly journals Effect of Interface Friction on Passive Force on Bridge Abutments

2019 ◽  
Vol 92 ◽  
pp. 13013
Author(s):  
Kyle Rollins ◽  
Amy Fredrickson ◽  
Eric Scott
Keyword(s):  
Large Scale ◽  
Reinforced Soil ◽  
Passive Force ◽  
Interface Friction ◽  
Geosynthetic Reinforced Soil ◽  
Large Scale Testing ◽  
Highly Sensitive ◽  
Earth Pressures ◽  
Backfill Materials ◽  
Correct Understanding

A correct understanding of passive force-deflection response is important for lateral load evaluations of bridges during extreme events such as earthquakes and from thermal expansion and contraction of the superstructure. In these cases, the ultimate passive force is highly sensitive to the interface friction between the abutment wall and the adjacent geomaterials. These geomaterials may simply consist of compacted sand or gravel; however, for geosynthetic reinforced soil (GRS) backfill a geosynthetic fabric may be placed between the abutment wall and soil which can reduce the interface friction. In still other cases, a zone of compressible material such as geofoam may be used as a barrier between the soil and abutment to reduce lateral earth pressures. To evaluate the effect of the interface friction on passive force-deflection curves, large-scale testing was performed with a test abutment that was 3.35 m wide and 1.68 m high. Backfill materials consisted of sand, gravel, GRS backfill, and a geofoam inclusion between a sand backfill and the abutment. As a result of lower interface friction, the GRS backfills only developed 80% of the force developed by the unreinforced gravel. The geofoam inclusion decreased the passive force by about 70% as a result of reduced interface friction.

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