No abstract

No abstract

Large deformation of roadway and floor burst are the two major geotechnical hazards encountered with high mining stress in deep mines. In this paper, the stress and energy conditions generated by the impact damage on the rock surrounding a roadway are analyzed, and UDEC software was used to study the deformation characteristics of the roadway, as well as its failure mechanism under the influence of superimposed dynamic and static loads. The results indicate that the soft floor of a deep-buried roadway has a high damage degree and an obvious stress release effect, high static load leads to slow floor heave, and strong dynamic load disturbance is the principal trigger leading to floor burst. In addition, the anisotropy caused by the bedding surface weakens the cooperative characteristics of the support system, resulting in serious instability of the whole rock surrounding the roadway. Full-section anchor cables and inverted arches were adopted to maintain the stability of the rock surrounding the roadway. The monitoring results obtained from field tests show that the adoption of the combined support system effectively avoids floor burst caused by the superposition of dynamic and static loads; the maximum floor heave is 67.9 mm, which is 95% lower than the original value, ensuring safety in coal mining operations.

We construct the ($$\beta $$ β -deformed) partition function hierarchies with W-representations. Based on the W-representations, we analyze the superintegrability property and derive their character expansions with respect to the Schur functions and Jack polynomials, respectively. Some well known superintegrable matrix models such as the Gaussian hermitian one-matrix model (in the external field), $$N\times N$$ N × N complex matrix model, $$\beta $$ β -deformed Gaussian hermitian and rectangular complex matrix models are contained in the constructed hierarchies.

No abstract