The Influence of Mixing Degree between Coarse and Fine Particles on the Strength of Offshore and Coast Foundations
Abstract
:1. Introduction
2. Index of Mixing Degree and DEM Model Verification Result
2.1. Index of Mixing Degree
2.2. DEM Model Verification Result
3. Specimen’s Properties and Simulation Parameters
3.1. Specimen’s Properties
3.2. Simulation Parameters
4. Results and Analyses
4.1. Macroscopic Variation in Strength with Mixing Degree
4.1.1. Shear Strength
4.1.2. Volumetric Strain and Dilatancy Angle
4.2. Mesomechanism of the Variation in Strength with Mixing Degree
4.2.1. Contact Number
4.2.2. The Fabric Structure
4.2.3. Contact Force
4.2.4. Distribution of Contacts
4.2.5. Force–Fabric Anisotropies
4.3. Influence of Coarse Content on the Increased Range of Peak Shear Strength
5. Conclusions
 (1)
 The peak shear strength increases with increasing mixing degree, while the critical shear strength is not affected. This trend is consistent with that of volumetric strain with increasing mixing degree, and the variation in peak shear strength is directly related to the peak dilatancy angle.
 (2)
 The variations in both the peak and critical shear strengths are mainly affected by the cf contact type. Specifically, when the mixing degree increases, the mean normal force of cf contacts does not change, while the increase in the number of cf contacts and their global distribution contribute to the increase in peak shear strength. The increase in the cf contact number and the changes in the distribution of cf contacts from local to global offset the influence of the reduction in the mean normal forces of the cc, cf and ff contacts and the cc and ff contact numbers, which results in stable critical shear strength.
 (3)
 The force–fabric anisotropies of the whole contact network and three subnetworks are evaluated. The force–fabric anisotropies of the whole contact network explain the microscopic mechanism of the strength. The increase in peak strength is mainly caused by the increase in 0.4a_{n}. And the increase in 0.4a_{n} and 0.6a_{t}, with a decrease in 0.4a_{c}, offsets each other, which maintain the stability of the critical strength. The meticulous analysis of the force–fabric anisotropies of three subnetworks affords a way to explain the micromechanisms that result in the dependency of the contributions of different contact types to the strength on the mixing degree.
 (4)
 The range of coarse contents conformed to the definition of binary geotechnical mixture and the influence of the mixing degree on the peak shear strength increases with increasing coarse content. This means that with a higher coarse content, a greater influence of the mixing degree on the shear strength performance of binary geotechnical mixture should be considered.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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State  Specimen 
$${\overline{\mathit{f}}}_{\mathbf{n}}\_\mathbf{cc}\left(\mathbf{N}\right)$$

$${\overline{\mathit{f}}}_{\mathbf{n}}\_\mathbf{cf}\left(\mathbf{N}\right)$$

$${\overline{\mathit{f}}}_{\mathbf{n}}\_\mathbf{ff}\left(\mathbf{N}\right)$$

$${\overline{\mathit{f}}}_{\mathbf{n}}\left(\mathbf{N}\right)$$
 C_{cc}  C_{cf}  C_{ff} 

peak  I = 0.0  2795.68  250.28  117.78  149.95  403  756  36,211 
I = 0.2  2796.66  246.22  126.88  160.88  362  2062  33,239  
I = 0.4  2664.39  250.87  125.23  162.89  309  3083  30,310  
I = 0.6  2936.14  248.44  127.54  164.82  227  5230  27,208  
I = 0.8  2833.42  256.10  129.67  161.64  116  6714  25,614  
I = 1.0  3272.87  255.50  124.99  169.73  96  7802  20,904  
critical  I = 0.0  2104.77  326.81  114.41  144.26  398  1173  31,348 
I = 0.2  2153.30  312.60  113.70  149.69  343  2099  27,270  
I = 0.4  1997.71  302.12  113.09  154.18  312  3006  24,827  
I = 0.6  1853.70  290.62  106.88  154.75  210  4627  20,895  
I = 0.8  1718.37  274.28  96.98  139.63  97  5863  19,102  
I = 1.0  1649.24  245.63  99.41  136.64  76  6657  18,589 
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Liu, S.; Nie, Y.; Hu, W.; Ashiru, M.; Li, Z.; Zuo, J. The Influence of Mixing Degree between Coarse and Fine Particles on the Strength of Offshore and Coast Foundations. Sustainability 2022, 14, 9177. https://doi.org/10.3390/su14159177
Liu S, Nie Y, Hu W, Ashiru M, Li Z, Zuo J. The Influence of Mixing Degree between Coarse and Fine Particles on the Strength of Offshore and Coast Foundations. Sustainability. 2022; 14(15):9177. https://doi.org/10.3390/su14159177
Chicago/Turabian StyleLiu, Shunkai, Yuxing Nie, Wei Hu, Mohammed Ashiru, Zhong Li, and Jun Zuo. 2022. "The Influence of Mixing Degree between Coarse and Fine Particles on the Strength of Offshore and Coast Foundations" Sustainability 14, no. 15: 9177. https://doi.org/10.3390/su14159177