Characterizations of macroscopic deformation and particle crushing of crushed gangue particle material under cyclic loading: In solid backfilling coal mining

2019 ◽  
Vol 343 ◽  
pp. 159-169 ◽  
Author(s):  
Junmeng Li ◽  
Yanli Huang ◽  
Zhongwei Chen ◽  
Jixiong Zhang ◽  
Haiqiang Jiang ◽  
...  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zhong-Ming He ◽  
Da Xiang ◽  
Ya-Xin Liu ◽  
Qian-Feng Gao ◽  
Han-Bing Bian

This study aims to examine the deformation behavior and internal mechanism of coarse-grained soil as an embankment filler under cyclic loading. Numerical dynamic triaxial tests were performed on coarse-grained soil using the discrete element software PFC3D. The numerical model was verified by comparing the numerical results with the experimental data. Afterward, the changes in the porosity, force chain, and particle movement of coarse-grained soil samples were analyzed, and the mesoscopic deformation behavior of coarse-grained soil under cyclic loading was investigated. The research results show that with the increase of the deviatoric stress amplitude, moisture content, and loading frequency, the deformation of the soil increases and the ability to resist deformation decreases at the same loading cycles. Due to the inhomogeneous distribution of particles with different sizes, the velocity and displacement of the sample vary in different directions, exhibiting mesoscopic anisotropy. The contact force is relatively even in the downward direction while dispersed near the edge of the sample. This means that the particles at the bottom are less affected by loads and the internal evolution of soil samples conforms to its macroscopic deformation behavior during cyclic loading.


Minerals ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 244 ◽  
Author(s):  
Junmeng Li ◽  
Yanli Huang ◽  
Zhongwei Chen ◽  
Meng Li ◽  
Ming Qiao ◽  
...  

1886 ◽  
Vol 22 (560supp) ◽  
pp. 8940-8940 ◽  
Keyword(s):  

2020 ◽  
Vol 21 (5) ◽  
pp. 505
Author(s):  
Yousef Ghaderi Dehkordi ◽  
Ali Pourkamali Anaraki ◽  
Amir Reza Shahani

The prediction of residual stress relaxation is essential to assess the safety of welded components. This paper aims to study the influence of various effective parameters on residual stress relaxation under cyclic loading. In this regard, a 3D finite element modeling is performed to determine the residual stress in welded aluminum plates. The accuracy of this analysis is verified through experiment. To study the plasticity effect on stress relaxation, two plasticity models are implemented: perfect plasticity and combined isotropic-kinematic hardening. Hence, cyclic plasticity characterization of the material is specified by low cycle fatigue tests. It is found that the perfect plasticity leads to greater stress relaxation. In order to propose an accurate model to compute the residual stress relaxation, the Taguchi L18 array with four 3-level factors and one 6-level is employed. Using statistical analysis, the order of factors based on their effect on stress relaxation is determined as mean stress, stress amplitude, initial residual stress, and number of cycles. In addition, the stress relaxation increases with an increase in mean stress and stress amplitude.


2001 ◽  
Vol 23 (2) ◽  
pp. 91-103
Author(s):  
JAMIE HAMILTON ◽  
CIARA CLARKE ◽  
ANDREW DUNWELL ◽  
RICHARD TIPPING

This report presents the results of the excavation of a stone ford laid across the base of a small stream valley near Rough Castle, Falkirk. It was discovered during an opencast coal mining project. Radiocarbon dates and pollen analysis of deposits overlying the ford combine to indicate a date for its construction no later than the early first millennium cal BC. Interpreting this evidence was not straightforward and the report raises significant issues about site formation processes and the interpretation of radiocarbon and pollen evidence. The importance of these issues extends beyond the rarely investigated features such as fords and deserve a larger place in the archaeological literature.


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