Orthogonal Numerical Analysis of Deformation and Failure Characteristics of Deep Roadway in Coal Mines: A Case Study

Abstract

With the development of deep, underground coal mines in China, the failure mechanism of the rocks surrounding roadways is becoming increasingly complicated and the deformational control is also significantly difficult. In this study, based on the temporal and spatial deformational distribution of the deep roadway area in the 2233 working face of Fuxin Hengda Coal Mine, factors affecting the deformation and failure mechanism of deep-buried roadways, such as cohesion (c), tensile strength (), internal friction angle (φ), vertical ground stress (p), and the horizontal-to-vertical stress ratio (λ), were analyzed using orthogonal numerical experiments. The stress and electromagnetic radiation monitoring data were used to locate areas of highly concentrated deformation in the roadway and surrounding rocks. The results show that the order of the degree of influence of the surrounding rock and geometric parameters on the deformation of the deep-buried roadway is φ > p> > λ > c. The vertical stress of the roof and the horizontal stress of the two sides are negatively correlated with the tensile strength and horizontal-to-vertical stress ratio, respectively, and mainly shear failure occurs in the area. The higher the level of the surrounding rock, the more serious is the deterioration and deformation. The electromagnetic radiation reflects the distribution range of the high-stress concentration area and strength deterioration area. The test results accurately describe the deformation–deterioration-failure laws of rock surrounding deep-buried roadways influenced by different factors. The results are of great significance for analyzing the deformation and failure characteristics of rocks surrounding roadways, preventing rockburst, and supporting the parameter optimization of roadways.

Supporting optimization of thick seam roadway with top coal based on orthogonal matrix analysis

“…The evaluation of surrounding rock support effect is a comprehensive evaluation of multi-factor indicators, therefore a three-layer data model is constructed based on the above orthogonal experimental data 32 . The anchor cable prestress, length and spacing are used as the factor layers, and the top plate, the deformation of the two sides and the volume of the plastic zone are used as www.nature.com/scientificreports/ the test evaluation index layers, as shown in Table 6.…”

Numerical simulation of roadway deformation and failure under different degrees of dynamic disturbance

“…The orthogonal design experiment method is a mathematical-statistical method suitable for multi-factor experiments 45 . In order to explore the failure and deformation of the roadway under the dynamic disturbance condition under the multi-factor condition, the orthogonal experiment method is adopted.…”

Analytical Damage Model for Predicting Coal Failure Stresses by Utilizing Acoustic Emission

“…In simulation, using PFC 2D software, the results indicated that increasing water content within the rock significantly decreased the coal strength, strain ratio (strain to peak strain), Young's modulus, AE energy (average), and the maximum energy of a single AE event. Some researchers used strain energy density for fracture predictions [44][45][46][47]. Lin et al studied the AE parameters during disccutter-induced rock fragmentation processes under various water conditions [48].…”

“…Scholars studied the evolution of microcracks in rocks under saturated conditions using AE data [49]. The results demonstrated that the varying characteristics of rock crack propagation could be characterized by the AE events frequency along with volume change [12,28,46,50].The change in P-wave velocity along with AE parameters in porous rock were studied after micro-crack closure by Fortin et al and Liu et al [51,52]. Zhou et al have taken sandstone under different water contents as a research object and investigated AE characteristics along with the type I fracture mechanism [53].…”