Discrete element analysis of structural characteristics of stepped reinforced soil retaining wall

In cold regions, ice pressure poses a serious threat to the safe operation of ship hulls and fixed offshore platforms. In this study, a discrete element method (DEM) with bonded particles was adapted to simulate the generation and distribution of local ice pressures during the interaction between level ice and vertical structures. The strength and failure mode of simulated sea ice under uniaxial compression were consistent with the experimental results, which verifies the accuracy of the discrete element parameters. The crushing process of sea ice acting on the vertical structure simulated by the DEM was compared with the field test. The distribution of ice pressure on the contact surface was calculated, and it was found that the local ice pressure was much greater than the global ice pressure. The high-pressure zones in sea ice are mainly caused by its simultaneous destruction, and these zones are primarily distributed near the midline of the contact area of sea ice and the structure. The contact area and loading rate are the two main factors affecting the high-pressure zones. The maximum local and global ice pressures decrease with an increase in the contact area. The influence of the loading rate on the local ice pressure is caused by the change in the sea ice failure mode. When the loading rate is low, ductile failure of sea ice occurs, and the ice pressure increases with the increase in the loading rate. When the loading rate is high, brittle failure of sea ice occurs, and the ice pressure decreases with an increase in the loading rate. This DEM study of sea ice can reasonably predict the distribution of high-pressure zones on marine structures and provide a reference for the anti-ice performance design of marine structures.

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Dynamic Response of Reinforced Soil Retaining Wall Resting on Soft Clay

Transportation Infrastructure Geotechnology ◽

10.1007/s40515-021-00156-9 ◽

2021 ◽

Author(s):

Ripon Hore ◽

Sudipta Chakraborty ◽

Ayaz Mahmud Shuvon ◽

Md. Fayjul Bari ◽

Mehedi A. Ansary

Keyword(s):

Dynamic Response ◽

Retaining Wall ◽

Soft Clay ◽

Reinforced Soil

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Discrete element analysis of the punching behaviour of a secured drapery system: from laboratory characterization to idealized in situ conditions

Acta Geotechnica ◽

10.1007/s11440-020-01119-z ◽

2021 ◽

Author(s):

Antonio Pol ◽

Fabio Gabrieli ◽

Lorenzo Brezzi

Keyword(s):

Mechanical Response ◽

Steel Wire ◽

Discrete Element ◽

Wire Mesh ◽

Steel Plates ◽

Loading Conditions ◽

Element Analysis ◽

In Situ Conditions ◽

Wire Meshes

AbstractIn this work, the mechanical response of a steel wire mesh panel against a punching load is studied starting from laboratory test conditions and extending the results to field applications. Wire meshes anchored with bolts and steel plates are extensively used in rockfall protection and slope stabilization. Their performances are evaluated through laboratory tests, but the mechanical constraints, the geometry and the loading conditions may strongly differ from the in situ conditions leading to incorrect estimations of the strength of the mesh. In this work, the discrete element method is used to simulate a wire mesh. After validation of the numerical mesh model against experimental data, the punching behaviour of an anchored mesh panel is investigated in order to obtain a more realistic characterization of the mesh mechanical response in field conditions. The dimension of the punching element, its position, the anchor plate size and the anchor spacing are varied, providing analytical relationships able to predict the panel response in different loading conditions. Furthermore, the mesh panel aspect ratio is analysed showing the existence of an optimal value. The results of this study can provide useful information to practitioners for designing secured drapery systems, as well as for the assessment of their safety conditions.

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Comparison of Field Behavior with Results from Numerical Analysis of a Geosynthetic Reinforced Soil Integrated Bridge System Subjected to Thermal Effects

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198119899043 ◽

2020 ◽

Vol 2674 (1) ◽

pp. 294-306

Author(s):

Arshia Taeb ◽

Phillip S.K. Ooi

Keyword(s):

Pressure Fluctuations ◽

Axial Loading ◽

Reinforced Soil ◽

Element Analysis ◽

Vertical Pressure ◽

Geosynthetic Reinforced Soil ◽

End Wall ◽

Cyclic Straining ◽

Toe Pressure ◽

Bridge System

When subjected to ambient daily temperature fluctuations, a 109.5 ft-long geosynthetic reinforced soil integrated bridge system (GRS-IBS) was observed to undergo cyclic straining of the superstructure. The upper and lower reaches of the superstructure experienced the highest and lowest strain fluctuation, respectively. These non-uniform strains impose not only axial loading of the superstructure but also bending. Pure axial loading in a horizontal superstructure will cause the footings to slide. However, bending in the superstructure will cause the footings to rotate thereby inducing cyclic fluctuations of the vertical pressure beneath the footing and also lateral pressure behind the end walls. Measured vertical footing pressure closest to the stream experienced the greatest daily pressure fluctuation (≈ 2,500–3,000 psf), while that nearest the end wall experienced the least. The toe pressure fluctuations seem rather large. That these large vertical pressure fluctuations are observed in a tropical climate like Hawaii when no other GRS-IBS in temperate regions has reported the same (or perhaps higher fluctuation) is indeed surprising. The larger these pressures are, the greater the likelihood of inducing cyclic-induced deformations of the GRS abutment. A finite element analysis of the same GRS-IBS was performed by applying an equivalent temperature and gradient to the superstructure over the coldest and hottest periods of a day to see if the field measured values of pressures are reasonable and verifiable, which indeed they were. This methodology is novel in the sense that the effects of axial load and bending of the superstructure are simulated using measured strains rather than measured temperatures.

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