Fig 1.
Red mud emissions and comprehensive utilization rate in China in the past decade (incomplete statistics).
Table 1.
Statistics of red mud modified materials.
Fig 2.
Schematic diagram of RMBF backfill inverted arch.
Fig 3.
Sample collection and preparation.
(a) Cement, (b) Steel slag, (c) Slaked lime, (d) EDTA-2Na.
Table 2.
Compaction test plan.
Table 3.
Unconfined compressive strength test plan.
Table 4.
Self-weight stress calculation.
Table 5.
Triaxial compression test plan for RMBF.
Fig 4.
(a) Sample Preparation, (b) GDSTTS test system.
Table 6.
Compaction test results.
Fig 5.
Compaction test curves.
Fig 6.
Failure mode of UCS test for MRM (28d, 96% compaction degree).
(a) 5%, (b) 15%, (c) 20%, (d) 30%.
Fig 7.
Unconfined compressive strength of MRM.
(a) 7d, (b) 28d.
Fig 8.
The changing trend of unconfined compressive strength of MRM.
(a) 7d, (b) 28d.
Fig 9.
Unconfined compressive strength of MRM after adding soil stabilizers.
(a) 7d, (b) 28d.
Fig 10.
The (σ1-σ3)-ε1 curves of RMBF with confining pressure under different ages.
(a) 7d, (b) 14d, (c) 28d, (d) 28d-30kPa.
Fig 11.
The failure mode of triaxial compression test for RMBF.
(a) TA3, (b) TB1, (c) TC2.
Fig 12.
The changing trend of E and (σ1-σ3)f of RMBF.
(a) E -age, (b) E -confining pressure, (c) (σ1-σ3)f -age, (d) (σ1-σ3)f -confining pressure.
Fig 13.
The (σ1-σ3)-ε1 curves of URM with confining pressure under different ages.
(a) 7d, (b) 14d, (c) 28d.
Fig 14.
The (σ1-σ3)-ε1 curves of MRM with confining pressure under different ages.
(a) 7d, (b) 14d, (c) 28d.
Fig 15.
(a) 7d, (b) 14d, (c) 28d.
Fig 16.
Strengthening stress-strain curve of RMBF.
(a) 7d, (b) 14d, (c) 28d.
Table 7.
Test constants a, b, E0, (σ1-σ3)sult and Rf of Duncan-Chang model for RMBF considering Sp.
Fig 17.
The “ab line” of RMBF considering Sp.
(a) 7d-30kPa, (b) 7d-60kPa, (c) 7d-90kPa, (d) 14d-30kPa, (e) 14d-60kPa, (f) 14d-90kPa, (g) 28d-30kPa, (h) 28d-60kPa, (i) 28d-90kPa.
Table 8.
Material constants K and n of Duncan-Chang model for RMBF considering Sp.
Fig 18.
The “Kn line” of RMBF considering Sp.
(a) 7d, (b) 14d, (c) 28d.
Table 9.
Material constants c and φ of Duncan-Chang model for RMBF considering Sp.
Fig 19.
Mohr stress circle of RMBF considering Sp.
(a) 7d, (b) 14d, (c) 28d.
Table 10.
Test constant f and material constant D of Duncan-Chang model for RMBF considering Sp.
Fig 20.
The “Df line” of RMBF considering Sp.
(a) 7d, (b) 14d, (c) 28d.
Table 11.
The material constants G and F of Duncan-Chang model for RMBF.
Fig 21.
The “GF line” of RMBF.
Table 12.
List of material constants of Duncan-Chang model for RMBF considering Sp.
Table 13.
List of fitting equations for material constants.
Fig 22.
Fitting lines for material constants of Duncan-Chang model for RMBF considering Sp.
(a) K-age, (b) n-age, (c) Rf-age, (d) c-age, (e) φ-age, (f) D-age, (g) G-age, (h) F-age.
Fig 23.
The (σ1-σ3)-ε1 curves calculated by Duncan-Chang model for RMBF considering Sp.
(a) 7d, (b) 14d, (c) 28d.