two 0.8/0.2 20/5 Coal 14.2 20 1.6 four.24 2 0.25/0.0625 10/2.5 Gritstone 25.1 20 1.six 19.72 2 1.1/0.275 20/Note: In other numerical Safranin medchemexpress models, E usually represents the
2 0.8/0.two 20/5 Coal 14.two 20 1.6 4.24 2 0.25/0.0625 10/2.five Gritstone 25.1 20 1.six 19.72 two 1.1/0.275 20/Note: In other numerical models, E frequently represents the elastic modulus, and K normally represents the bulkmodulus. So as to distinguish these similar symbols, this paper uses E to represent the helpful modulus of flatjoint and K to represent the rigidity ratio of flat joint.two.3.3. Establishing the Model Depending on the geometric shape of your operating face as well as the actual survey information, the ratio with the periodic weighting step for the length of the operating face is 0.1.16, as well as the ratio with the initially weighting step for the length in the operating face is 0.25. The mechanical Appl. Sci. 2021, 11, x FOR PEER Review 8 of 16 parameters of Table 1 is often applied to establish a two-dimensional 400 108 m2 particle flow mining field model for simulating a coal seam along the strike, as shown in Figure 3.Figure 3. Numerical model. Figure 3. Numerical model.In the procedure of model calculation, the left boundary from the open-off cut eye distance Inside the process of model calculation, the left boundary on the open-off reduce eye dismodel is 50 m, which restricts the horizontal lateral AZD4625 web displacement of your left and right tance model is 50 m, which restricts the horizontal lateral displacement from the left and boundaries from the model and allows vertical movement. The upper boundary can be a no cost suitable boundaries in the model and allows vertical movement. The upper boundary is a boundary, as well as the lower boundary restricts the vertical displacement and allows horizontal free of charge boundary, along with the lower boundary restricts the vertical displacement and enables movement. The model is loaded with gravity (the gravity acceleration is 9.8 m/s2 ) and horizontal movement. The model is loaded with gravity (the gravity acceleration is 9.eight advances 8 m every single time. The model consists of 174,366 particles using a particle radius ratio m/s2) and advances 8 m every single time. The model consists of 174,366 particles with a particle of 1.six and a minimum radius of 20 cm. The overlying strata are layered and simulated by radius ratio of 1.six and a minimum radius of 20 cm. The overlying strata are layered and giving different mechanical parameters. simulated by providing distinct mechanical parameters. three. Outcomes three. Final results three.1. Morphological Qualities of Overburden Caving 3.1. Morphological Traits of Overburden Caving overlying strata might be impacted by Inside the procedure of the functioning face advancing, theIn the approach mining, and also the corresponding movement and deformation will take place. unique degrees of of your functioning face advancing, the overlying strata will likely be impacted by Figure four shows the of mining, as well as the corresponding movement and deformation face diverse degrees evolution of overlying strata collapse in the procedure in the functioning will advancing. occur. Figure 4 shows the evolution of overlying strata collapse within the method on the operating face advancing. The functioning face is advanced along the uphill direction in the open cut. When the coal seam is mined 80 m, the very first caving happens within the operating face, along with the caving height is 17.three m. The development is terminated within the S3 strata, and the collapsed rockAppl. Sci. 2021, 11, 10276 Appl. Sci. 2021, 11, x FOR PEER REVIEW8 of 15 9 ofFigure 4. Rock caving patterns at diverse advancing distances. Figure four. Rock caving patterns at different advancing distances.The operating face is sophisticated along the uphill path from the open cut.
