The Tashan coal mine is selected as a case study to determine the deformation and damage mechanisms of lower roadway in close-range residual pillar area. Roof drilling peephole technology applied detect roof surrounding rock. A boundary invisibility equation derived for plastic zone circular hole based on theory butterfly non-uniform stress field which principal occurs at an arbitrary angle ver...

Borehole radar can be used in a single-hole reflection mode or in a cross-hole tomography mode. In the reflection mode, radar provides an image of discontinuities in the bedrock surrounding a borehole, including bedding planes, lithologic contacts, fractures, and cavities. The measurements are either directional or omnidirectional, depending upon the type of equipment and antennas. In the tomog...

The high temperatures existing within a geothermal well preclude the use of most logging instrumentation which is necessary to study the wellbore and surrounding rock matrix. Possible solutions to this problem include cooling the wellbore and the surrounding rock by circulating fluid in the wellbore and by injecting fluid directly into the rock matrix. The latter method, however, is not preferr...

In coal mining, as the mining depth increases, a complex mechanical environment of “high ground stress”, temperature”, karst water pressure”, and “mining disturbance”, namely “three highs one disturbance” appears. Many roadways have characteristics soft rock with large deformation, pressure, difficult support, high support cost, which brings severe challenges to safe efficient production mines....

In this chapter, we present analytic calculations of gravitational waves from a particle orbiting a black hole. We first review the Teukolsky formalism for dealing with the gravitational perturbation of a black hole. Then we develop a systematic method to calculate higher order post-Newtonian corrections to the gravitational waves emitted by an orbiting particle. As applications of this method,...

Discontinuities are natural structures that exist in rocks and can affect the stability of rock structures. In this article, influence notch presence on strength failure evolution around a hole compressed specimens is investigated numerically. Firstly, uniaxial compressive test specimen with circular modeled, simulated. separate model, notches created at surface hole. Results show that, when zo...

The potential of sudden water accidents induced by damage to the bottom slab that forms a channel due action karst calls for research on law coal seam floors under coupling effect mining and water. In this study, situation floor rock was analyzed based theory mechanics fracture mechanics, combined with actual geological conditions floor. water-rock investigated using theoretical analysis mechan...

It has recently been proposed that microrefugia played an important role in species survival during past climate change events. However, the current distributions of microrefugia remain largely unknown. Wind-hole sites are areas affected by preferential flows of cool air generated in interstitial spaces created by rock fragments or colluvia. Alpine plant species occurring in lowland wind-hole s...