Ground Pressure under Mining Ore Bodies of Different Angles Based on Physical Simulation
Table 1
The final mixing proportioning scheme of field strata.
Lithology
Actual strength (MPa)
Simulated intensity (kPa)
Main ingredients
Matching plan
Remarks
Quaternary topsoil cover
2.19
17.76
River sand calcium carbonate: gypsum
6 : 7:3
Various rock layers near the No. 59 exploration line profile of the northern mining area of No. 2 pit in Jinning Phosphate Mine. Note: ① The amount of water added is the total 1/5~1/9; ② the amount of borax accounts for 1/100 of the added water; ③ the drying time of the model is 3 to 4 days; ④ add a total of 1/2 to 1/3 of plastic, soft rubber, motor oil, and sawdust powder to the fault.
Muddy dark gray hidden to the middle dolomite
35.16
284.70
River sand calcium carbonate: gypsum
2.5 : 1.2 : 8.8
Indirect roof layered muddy dolomite
24.78
200.65
River sand calcium carbonate: gypsum
2.8 : 3.45 : 6.55
Direct roof gravel-bearing quartz sandstone
22.87
185.18
River sand calcium carbonate: gypsum
3 : 1:9
Grade I phosphate rock
37.96
307.37
River sand calcium carbonate: gypsum
2.4 : 1.2 : 8.8
Grade II and III grade phosphorus ore
39.12
316.76
River sand calcium carbonate: gypsum
2.4 : 1:9
Direct floor grayish white thin to medium thick layered dolomite
39.35
318.62
River sand calcium carbonate: gypsum
2.4 : 1:9
Indirect floor gray-white thin to medium thick layered cryptocrystalline to fine-grained dolomite