Analysis of Layered Geogrids–Sand–Clay Reinforced Structures under Triaxial Compression by Discrete Element Method
Abstract
:1. Introduction
2. DEM Modeling
2.1. Particle Flow Simulation of Filler and Geogrid
2.2. Selection of Mesoparameters
3. Numerical Test Scheme
4. Results and Discussion
4.1. Relationship between Deviatoric Stress and Axial Strain
4.2. Shear Strength
5. Conclusions
- Laying the sand layers in the samples can significantly improve their post-peak strain-softening characteristics. Moreover, the geogrid embedment can further enhance the ductility of the samples. The effect of increasing the thickness of sand layers alone on the behaviors of LGSCR and SCL samples is minimal. Thus, in practical engineering, the setting mode of thin multi-sand layers should be adopted to improve the safety of LGSCR structures.
- The influence of the sand layer on the peak stress of LGSCR and SCL samples improves with an increase in the confining pressure. Higher confining pressure causes a more significant difference in the peak stress on different LGSCR or SCL samples, which indicates that the effect of the sand layer on increasing the peak stress on the samples is more noticeable. Thus, raising the number of sand layers reduces the cohesion of the samples but increases their internal friction angles. Therefore, a reasonable test pressure should be determined according to the actual stress state of the LGSCR structure in engineering applications.
- Compared with the SCL samples, the LGSCR samples with geogrid embedment have a higher peak strength under specific confining pressure, and in terms of the shear strength index, the apparent cohesion of the LGSCR samples is larger than that of the SCL samples. Furthermore, the internal friction angle of the LGSCR samples is also larger than that of the SCL samples when the number of sand layers is equal to or greater than two.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Material | Clay | Sand | Geogrid |
---|---|---|---|
Specific gravity of particle | 2.00 | 2.63 | 1.00 |
Porosity of assembly | 0.40 | 0.40 | |
Minimum nominal radius of particle (mm) | 0.70 | 0.75 | 0.50 |
Maximum nominal radius of particle (mm) | 0.95 | 1.00 | 0.50 |
Contact normal stiffness (N/m) | 6.00 × 104 | 8.00 × 104 | 4.00 × 104 |
Contact shear stiffness (N/m) | 6.00 × 104 | 8.00 × 104 | 4.00 × 104 |
Coefficient of friction | 0.30 | 0.60 | 0.60 |
Contact bond normal strength (N/m2) | 1.00 × 105 | ||
Contact bond shear strength (N/m2) | 1.00 × 105 | ||
Parallel bond normal stiffness (N/m3) | 1.00 × 1016 | ||
Parallel bond shear stiffness (N/m3) | 1.00 × 1016 | ||
Parallel bond normal strength (N/m2) | 3.00 × 1015 | ||
Parallel bond shear strength (N/m2) | 3.00 × 1015 |
Improvement or Deterioration Percentages | Addition of Sand Layers in Pure Clay Samples | Addition of Geogrids in SCL Samples | Addition of Geogrid-Reinforced Sand Layers in Pure Clay Samples |
---|---|---|---|
φ (three points) | 22.6% | 12.7% | 38.2% |
φ (five points) | 20.9% | 8.4% | 31.1% |
c (three points) | −37.2% | 41.6% | −11.2% |
c (five points) | −24.3% | 54.8% | 17.1% |
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Cui, L.; Cao, W.; Sheng, Q.; Xie, M.; Yang, T.; Xiao, P. Analysis of Layered Geogrids–Sand–Clay Reinforced Structures under Triaxial Compression by Discrete Element Method. Appl. Sci. 2021, 11, 9952. https://doi.org/10.3390/app11219952
Cui L, Cao W, Sheng Q, Xie M, Yang T, Xiao P. Analysis of Layered Geogrids–Sand–Clay Reinforced Structures under Triaxial Compression by Discrete Element Method. Applied Sciences. 2021; 11(21):9952. https://doi.org/10.3390/app11219952
Chicago/Turabian StyleCui, Lan, Wenzhao Cao, Qian Sheng, Mingxing Xie, Tao Yang, and Ping Xiao. 2021. "Analysis of Layered Geogrids–Sand–Clay Reinforced Structures under Triaxial Compression by Discrete Element Method" Applied Sciences 11, no. 21: 9952. https://doi.org/10.3390/app11219952
APA StyleCui, L., Cao, W., Sheng, Q., Xie, M., Yang, T., & Xiao, P. (2021). Analysis of Layered Geogrids–Sand–Clay Reinforced Structures under Triaxial Compression by Discrete Element Method. Applied Sciences, 11(21), 9952. https://doi.org/10.3390/app11219952