Research on Physical Similarity Simulation of Mining Uphill and Downhill at the Large-Angle Working Face

Abstract

With the development of coal mining and the continuous expansion of mining intensity, large dip angle comprehensive mechanized coal mining as an important development direction and goal has become a worldwide research topic in the coal industry. The working face faces many production problems that need to be solved, such as the large-angle downhill mining, the large-angle uphill mining, and other complicated geological conditions (such as skew, anticline, and fault). In view of the above problems, with the specific conditions of Xinji No. 2 Mine, through the physical similarity simulation, the research on the roof movement law of the fully mechanized mining face under the mining conditions of large dip angle (depression angle and elevation angle are more than 40° and 20°, respectively) is studied. The distribution law of abutment pressure, movement law, and distribution range of water-conducting fracture zone after mining are emphasized. Meanwhile, the paper analyzes and compares the related mining pressure law of inclined longwall fully mechanized mining face under general conditions, forming a systematic, comprehensive, and scientific understanding of the law of mining pressure under such conditions. This achievement is of great significance to the prevention and control of water, support design, safety production, environmental improvement, improvement of enterprise efficiency, and advancement of coal science and technology.

Study on Law of Overlying Strata Breakage and Migration in Downward Mining of Extremely Close Coal Seams by Physical Similarity Simulation

“…Geometric, time, and dynamic similarities must be considered between the model and prototype. Based on [18] and "dimensional analysis," the dynamic similarity rate is presented as shown in equation ( 4). Meanwhile, Ren et al [36] indicated that the dynamic similarity requires the force of the model and…”

“…Niu et al [17] constructed a similar physical model of coal rock to verify that a new method could be applied for the monitoring and early warning of coal and rock dynamic disasters. Zhang et al [18] discussed the roof movement law of a fully mechanized mining face under a large dip angle through physical similarity simulations. Based on the engineering background of the Wuhushan coal mine, the law of overlying strata breakage and migration in the downward mining of extremely close coal seams was studied using the physical similitude modeling method.…”

Movement laws of overlying strata and prevention measures of dynamic disasters under deep adjacent coal seam group with high gas

“…In this study, considering that the geometric similarity ratio of the model to the prototype was 1:100 in the simulation of the mining processes of the working face, 10 mm in the model represented 1 m in the prototype (Zhang et al 2019). Therefore, in order to more intuitively represent the processes and results of the similarity simulation experiments, the data in the prototype were used to replace the experimental data in the model when describing the phenomena.…”

Similarity Simulation on the Movement Characteristics of Surrounding Rock and Floor Stress Distribution for Large-Dip Coal Seam

“…In addition, Dezhong Kong et al [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ] studied the distribution law of floor stress, roof fracture distribution, and large-dip coal seam fracture modes via a similarity simulation and numerical modeling. With the consideration of the asymmetric failure mechanism of overburden, Ding Lang et al [ 15 , 16 , 17 , 18 ] proposed the stability control technology of roadway-surrounding rock.…”