LI Xiulei, SHI Jianyong, LI Yuping. Influence of stress path on stress-strain behavior of municipal solid waste[J]. 2023, 55(2): 134-142.
DOI:
LI Xiulei, SHI Jianyong, LI Yuping. Influence of stress path on stress-strain behavior of municipal solid waste[J]. 2023, 55(2): 134-142.DOI: 10.11918/202111035.
Influence of stress path on stress-strain behavior of municipal solid waste
There are various stress states of solid waste mass in landfills (e.g.
compression
tension
loading
and unloading)
which are difficult to be fully simulated by using conventional triaxial tests and direct shear tests. Triaxial tests on reconstituted municipal solid waste (MSW) specimens under nine stress paths were carried out by GDS triaxial apparatus to analyze the influence of stress path on the stress-strain behavior and yielding characteristics of MSW. A unified mathematical model was proposed to describe the stress-stain responses of MSW
and the yielding locus of MSW was obtained in p-q stress space. By comparing the stress-strain relationships of sand soil and MSW
the effects of stress path on the reinforcement of fiber materials in MSW were discussed. Results show that for compression stress path with σ3≥0
the stress-strain curves of MSW exhibited an upward curvature without any peak or asymptotic values
and the reinforcing effect of fiber materials was the most significant. For compression stress path with σ3<0
the deviatoric stress of MSW increased with increasing axial strain and it gradually tended to a certain value
while the fibrous reinforcement was weak. For extension stress path with Δq<0
the stress-strain relationships of MSW were almost the same as those of sand soil
and there was no fibrous reinforcing effect in MSW. In conclusion
the fibrous reinforcing effect in MSW is closely related to stress path
and the research data provides a basis for comprehensive and in-depth understanding of the mechanical properties of MSW.