Study on multi-field catastrophe evolution laws of water inrush from concealed karst cave in roadway excavation: a case of Jiyuan coal mine

Figures & data

Figure 1. Location of the study area.

Figure 2. Geological profile of water inrush site.

Figure 3. Schematic diagram of numerical calculation model.

Figure 4. Layout of monitoring points.

Table 1. Simulation calculation parameters.

Parameter Lithology	Elastic modulus （GPa）	Poisson's ratio	Cohesion （MPa）	Internal friction angle （°）	Tensile strength （MPa）	Density （kg/m^3）	Porosity	Permeability coefficient （10^-3m/s）
Claystone	6.1	0.2	0.92	46	1.12	2550	0.01	0.008
Marl	9.5	0.2	1.9	35	1.6	2600	0.17	0.06
Changxing limestone	9.7	0.24	2.1	37	1.73	2650	0.18	0.07
Mudstone	10.6	0.35	2.70	30	1.33	2500	0.20	0.05
Coal seam	2.2	0.28	0.46	31	0.43	2000	0.24	0.11
Siltstone	13.1	0.17	2.39	45	1.25	2600	0.19	0.025
Maokou limestone	11.4	0.21	2.68	32	1.98	2700	0.15	0.052

Figure 5. Stress Distribution when approaching the karst cave.

Figure 6. (a) Variation law of roof stress monitoring points, (b) Variation law of floor stress monitoring points.

Figure 7. Displacement distribution when approaching the karst cave.

Figure 8. (a) Variation law of roof displacement monitoring points, (b) Variation law of floor displacement monitoring points.

Figure 9. Pore water pressure distribution when approaching the karst cave.

Figure 10. Variation law of pore water pressure at monitoring points in the plastic zone.

Figure 11. Variation in fluid velocity and positions of monitoring points.

Table 2. Numerical simulation schemes of water inrush under different geological conditions.

Schemes	Radius of karst cave (m)	Water pressure of karst cave (MPa)	Thickness of aquifuge (m)
Scheme 1	12, 14,16, 18, 20	1.5	2
Scheme 2	20	1, 1.5, 2, 2.5, 3	2
Scheme 3	20	1.5	2, 4, 6, 8, 10

Figure 12. (a) Groundwater velocity variations at monitoring point, (b) Groundwater pressure variations at monitoring points.

Figure 13. The stress variation of the aquiclude under different cave radius.

Figure 14. The displacement variation of the aquiclude under different cave radius.

Figure 15. The pore water pressure variation of the aquiclude under different cave radius.

Figure 16. The stress variation of the aquiclude under different cave water pressure.

Figure 17. The displacement variation of the aquiclude under different cave water pressure.

Figure 18. The pore water pressure variation of the aquiclude under different cave water pressure.

Figure 19. The stress variation of the aquiclude under different aquiclude thickness.

Figure 20. The displacement variation of the aquiclude under different aquiclude thickness.

Figure 21. The pore water pressure variation of the aquiclude under different aquiclude thickness.

Data availability statement

The data that support the findings of this study are available from the corresponding author, Dr Bo Li, upon reasonable request.