Three-Dimensional Simulation of a Load Transfer Mechanism for Frictional and End Bearing CMC Supported Embankments on Soft Soil

2016 ◽  
Author(s):  
Hamed Mahdavi ◽  
Behzad Fatahi ◽  
Hadi Khabbaz ◽  
Michal Krzeminski ◽  
Roger Santos ◽  
...  
Keyword(s):  
Load Transfer ◽  
Soft Soil ◽  
Three Dimensional ◽  
Transfer Mechanism ◽  
Load Transfer Mechanism ◽  
Dimensional Simulation

Influence of physical and geometrical parameters on three-dimensional load transfer mechanism at tunnel face

2009 ◽  
Vol 46 (7) ◽  
pp. 855-868 ◽  
Author(s):  
Ricardo A.M.P. Gomes ◽  
Tarcisio B. Celestino
Keyword(s):  
Load Transfer ◽  
Three Dimensional ◽  
Internal Force ◽  
Transfer Mechanism ◽  
Geometrical Parameters ◽  
Tunnel Face ◽  
Relative Stiffness ◽  
Load Transfer Mechanism ◽  
Internal Forces ◽  
Coarse Meshes

Three-dimensional discretizations used in numerical analyses of tunnel construction normally include excavation step lengths much shorter than tunnel cross-section dimensions. Simulations have usually worked around this problem by using excavation steps that are much larger than the actual physical steps used in a real tunnel excavation. In contrast, the analyses performed in this study were based on finely discretized meshes capable of reproducing the excavation lengths actually used in tunnels, and the results obtained for internal forces are up to 100% greater than those found in other analyses available in the literature. Whereas most reports conclude that internal forces depend on support delay length alone, this study shows that geometric path dependency (reflected by excavation round length) is very strong, even considering linear elasticity. Moreover, many other solutions found in the literature have also neglected the importance of the relative stiffness between the ground mass and support structure, probably owing to the relatively coarse meshes used in these studies. The analyses presented here show that relative stiffness may account for internal force discrepancies in the order of 60%. A dimensionless expression that takes all these parameters into account is presented as a good approximation for the load transfer mechanism at the tunnel face.

Geometrical effects on the load transfer mechanism of pile groups: three-dimensional numerical analysis

2018 ◽  
Vol 55 (5) ◽  
pp. 749-757 ◽  
Author(s):  
Yaru Lv ◽  
Dongdong Zhang
Keyword(s):  
Load Transfer ◽  
Three Dimensional ◽  
Bending Moment ◽  
Pile Group ◽  
Transfer Mechanism ◽  
Single Pile ◽  
Pile Groups ◽  
Load Transfer Mechanism ◽  
Side Resistance ◽  
Geometrical Effects

This paper investigates geometrical effects on the load transfer mechanism of off-ground capped pile groups subjected to vertical load by four three-dimensional numerical simulations, including a circular single pile, an X-shaped cross-sectional concrete (XCC) single pile, a 4 × 4 circular pile group, and a 4 × 4 XCC pile group. The ultimate bearing capacities of the XCC and circular piles within pile groups are approximately 0.86 and 0.74 times that of the XCC and circular single piles, respectively. The group efficiency of the XCC pile group is mainly improved by its side resistance. Comparing the XCC pile group to the circular pile group, the increment in side resistance is almost larger than the increment in pile perimeter, indicating that the pile geometry alters the load transfer mechanism via stress concentration and lateral stress arching. A nonuniform load distribution on piles within a capped pile group causes a bending moment along the pile shafts. The bending moment of XCC piles is smaller than that of circular piles because the raft stiffness of an XCC pile group is increased by its larger circumscribing pile diameter.

scholarly journals Load transfer mechanism of an unwelded, unbolted, grouted connection for prefabricated square tubular columns under axial loads

2020 ◽  
Vol 222 ◽  
pp. 111088
Author(s):  
Lili Sui ◽  
Shiyong Fan ◽  
Zhenyu Huang ◽  
Wei Zhang ◽  
Yingwu Zhou ◽  
...  
Keyword(s):  
Load Transfer ◽  
Transfer Mechanism ◽  
Axial Loads ◽  
Tubular Columns ◽  
Load Transfer Mechanism

Quantitative Analysis of Soft Soil Microstructure in Unloading Levels

2013 ◽  
Vol 401-403 ◽  
pp. 1529-1533 ◽  
Author(s):  
Qi Zhi Hu ◽  
Jing Xia Wang ◽  
Gao Liang Tao
Keyword(s):  
Quantitative Analysis ◽  
Soft Soil ◽  
Three Dimensional ◽  
Sem Images ◽  
3D Images ◽  
Soil Microstructure ◽  
Transverse Profile ◽  
Pore Area ◽  
Dimensional Simulation ◽  
Pore Number

Quantitative analysis of soft soil microstructure in unloading levels are made by using scanning electron microscope (SEM) images, IPP and PS of image technology ,which includes image segmentation, pore size measuring and counting, three dimensional simulation of soft soil microstructure, etc. The results indicate that, with the increase of unloading grade, pore number and area of big aperture are in a sharp increase, the corresponding porosity also in ascension, so the deformation of the soil is mainly due to the change of pore; compared with the apparent 3d images of soil under the transverse profile in unloading levels. The results also indicate that, with the increase of unloading grade, pore area of cross section are in a increase.

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