scholarly journals Soil Arching of Piled Embankment in Equal Settlement Pattern: A Discrete Element Analysis

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1627
Author(s):  
Kangyu Wang ◽  
Jun Cao ◽  
Xinquan Wang ◽  
Yingjie Ning
Keyword(s):  
Slip Surface ◽  
Discrete Element ◽  
Settlement Pattern ◽  
Differential Settlement ◽  
Test Model ◽  
Soil Arching ◽  
Element Analysis ◽  
Arching Effect ◽  
Pile Cap ◽  
Piled Embankment

Soil arching, which occurs in the piled embankments, plays an important role in stress redistribution between the relatively soft subsoil and the stiffer piles. The formation of the soil arching depends on the differential settlement of the embankment fill above the pile and the subsoil. The soil arching effect is barely investigated in the literature from the perspective of differential settlement of piles and soils. Based on the discrete element method (DEM), this paper develops a classic trapdoor test model to investigate the differential settlement in piled embankment during the downward movement of the trapdoor, and to explore the formation mechanism of soil arching in equal settlement pattern by changing the width of the pile cap and the height of the embankment. Due to symmetry, only one section of the laboratory test model is simulated herein. It was found that the soil arching formed under the equal settlement pattern remained unchanged after a certain degree of development, and the height of the equal settlement did not change at 0.7(s-a), where s is the pile spacing, and a is the width of the pile cap. The height of the embankment (H) and the width of the pile cap (a) have a significant influence on the formation of the equal settlement pattern when the width of the trapdoor is kept constant. Both the decrease in “H” and the increase in “a” facilitate the differential settlement of the soil between the piles and the pile-soil, enabling the slip surface to develop upward gradually, thereby hindering the formation of the equal settlement pattern.

Analysis of Behavior of Composite Foundation with Sparse Pile to Control Settlement

2012 ◽  
Vol 204-208 ◽  
pp. 674-679
Author(s):  
Jun Hui Zhang ◽  
Zhi Yong Yin ◽  
Jian Long Zheng
Keyword(s):  
Load Transfer ◽  
Computer Code ◽  
Differential Settlement ◽  
Composite Foundation ◽  
Soil Arching ◽  
Arching Effect ◽  
Soil Arching Effect ◽  
Rapid Construction ◽  
Membrane Effect ◽  
Pile Cap

The composite foundation with sparse piles to control settlement has been used to rapid construction and strict deformation of the structure widely currently, which can enhance the efficient of load transfer and decrease the differential settlement used with the geosynthetic. Considering the confine of analytical solution and the traditional method with a changeless modulus of geosynthetic and pile, the effects of the height of fill, the elastic modulus of geosynthetic and pile material on the differential settlement, embankment soil arching effect and tensioned membrane effect etc. are investigated using the computer code ABAQUS in this paper. The results indicate that the modulus of geosynthetic and pile has a notable influence on the differential settlement and the arching effect, which should be considered in the design. At the same time, the maximum tension in geosynthetic occurs near the edge of the pile cap.

Analysis of Settlement of Composite Foundation with Sparse Pile to Control Settlement

2012 ◽  
Vol 204-208 ◽  
pp. 664-669
Author(s):  
Jun Hui Zhang ◽  
Zhi Yong Yin ◽  
Jian Long Zheng
Keyword(s):  
Elastic Modulus ◽  
Significant Influence ◽  
Computer Code ◽  
Differential Settlement ◽  
Composite Foundation ◽  
Soil Arching ◽  
Maximum Settlement ◽  
Arching Effect ◽  
Soil Arching Effect ◽  
Pile Cap

The embankment soil arching effect of the composite foundation with sparse piles to control settlement is caused by the differential settlement between the embankment fill and the piles. So, the settlement is an important behaviour of the composite foundation. The effects of the height of embankment, the elastic modulus of geosynthetic and pile material, the stiffness of cushion and substratum, the pile cap and the distance of piles on the settlement are investigated using the computer code ABAQUS in this paper. The results indicate that the maximum settlement and differential settlement decrease with the elastic modulus of geosynthetic, the stiffness of cushion and substratum. The maximum settlement decreases and the differential settlement increases with the elastic modulus of pile material. At the same time, the differential settlement of the embankment surface decreases with the height of fill and there will be an equal settlement plane when the fill reaches certain height. In addition, the distance of piles has a more significant influence on settlement than the dimension of pile cap.

scholarly journals Similitude Conditions Modeling Geosynthetic-Reinforced Piled Embankments Using FEM and FDM Techniques

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Keith Jennings ◽  
Patrick J. Naughton
Keyword(s):  
Load Transfer ◽  
The Finite Element Method ◽  
Soil Arching ◽  
Absolute Value ◽  
Load Transfer Mechanism ◽  
Pile Cap ◽  
Model Geometry ◽  
Piled Embankment ◽  
Characteristic Trend ◽  
Piled Embankments

The numerical modelling of geosynthetic-reinforced piled embankments using both the finite element method (FEM) and finite difference method (FDM) are compared. Plaxis 2D (FEM) was utilized to replicate FLAC (FDM) analysis originally presented by Han and Gabr on a unit cell axisymmetric model within a geosynthetic reinforced piled embankment (GRPE). The FEM and FED techniques were found to be in reasonable agreement, in both characteristic trend and absolute value. FEM consistently replicated the FDM outputs for deformational, loading, and load transfer mechanism (soil arching) response within the reinforced piled embankment structure with a reasonable degree of accuracy. However the FDM approach was found to give a slightly higher reinforcement tension and stress concentration but lower reinforcement strain at the pile cap than FEM, which was attributed to the greater discretize of the model geometry in the FDM than in FEM.

scholarly journals Full-scale model study on variations of soil stress in geosynthetic-reinforced pile-supported track bed with water level change and cyclic loading

2019 ◽  
Vol 56 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Han-Lin Wang ◽  
Ren-Peng Chen ◽  
Wei Cheng ◽  
Shuai Qi ◽  
Yu-Jun Cui
Keyword(s):  
Cyclic Loading ◽  
Water Level ◽  
High Water ◽  
Scale Model ◽  
Soil Arching ◽  
Arching Effect ◽  
Soil Arching Effect ◽  
Soil Stress ◽  
Pile Cap ◽  
Level Lowering

This study presents a full-scale model investigation on variations of soil stress in a geosynthetic-reinforced pile-supported track bed at various water levels and loading cycles, with four testing procedures: water level rising, cyclic loading at high water level, water level lowering, and cyclic loading at low water level. The soil arching effect was revealed, characterized by higher stress above the pile cap. With the water level rising and loading cycles increasing at high water level, this effect becomes more pronounced, until a peak value of dynamic stress concentration ratio is reached. The stable state of soil arching is obtained earlier near the crown of soil arching, but this arching effect develops more significantly at the foot of soil arching. With the water level lowering and loading at low water level, the soil arching effect remains steady, with slightly changed dynamic stresses in the track bed. The geogrid shows a significant impact on the load transfer mechanism for the quasi-static stress: the quasi-static pile-cap stress presents higher values below the geogrid, whereas the opposite trend is observed for the water-bag (subsoil) area. Nevertheless, this mechanism is not obvious with respect to the dynamic stress, with the values showing no distinct difference above and below the geogrid.

scholarly journals Discrete Element Analysis of High-Pressure Zones of Sea Ice on Vertical Structures

2021 ◽  
Vol 9 (3) ◽  
pp. 348
Author(s):  
Xue Long ◽  
Lu Liu ◽  
Shewen Liu ◽  
Shunying Ji
Keyword(s):  
High Pressure ◽  
Sea Ice ◽  
Failure Mode ◽  
Contact Area ◽  
Loading Rate ◽  
Discrete Element ◽  
Offshore Platforms ◽  
Marine Structures ◽  
Element Analysis ◽  
Ice Pressure

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.

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

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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