Floor heave in the west wing track haulage roadway of the Tingnan Coal Mine: Mechanism and control

Floor heave of a roadway is a dynamic phenomenon that often happens in the roadways of coal mines. It seriously affects safe production in the coal mine. Floor heave has long been one of the most difficult problems to be resolved during coal mining. An analysis of floor heave in the soft rock surrounding the roadway, and the factors influencing it, allowed the deformation mechanism in the west wing double track haulage roadway of the Tingnan Coal Mine to be deduced. Three types of floor heave are observed there: intumescent floor heave, extrusion and mobility floor heave, and compound floor heave. Control measures are proposed that have been adopted during a recent repair engineering project. Control of the floor heave in the west wing track haulage roadway was demonstrated. The reliability and rationality of a combined support technology including floor anchors, an inverted arch, and anchoring of both sides was verified by mine pressure data and the field observations. Waterproofing measures were also under-taken to assist in the control of floor heave.

Stability assessment and feature analysis of slope in Nanfen Open Pit Iron Mine

Under the combined influences of special topography and the long term mining in Nanfen Open Pit Iron Mine, many large scale landslide masses appeared in heading side of stope, and tens of millions of iron mine is buried underside, making great economic losses. In order to guide the safety mining and increase the supply quantity, this paper through the use of MSARMA-method and the ''MSARMA evaluation and analytical system for slope stability analysis'' based on this method, which aimed at the quantitative evaluating of the slope stability before and after the actual mining below the slip mass, and the sensitivity analysis for the main influencing factor, providing scientific proof for the parameter optimization of open mine surface slope, the security and sustainable exploitation.

Wellhead anti-frost technology using deep mine geothermal energy

The auxiliary shaft is an important location for coal mine heating in the winter, where the main purpose of heating is to prevent icing of the shaft. Wellhead heating requires characteristics of openness, no-noise and big heat loads. The original coal-fired boiler heating mode causes significant waste of energy and environmental pollution due to the low efficiency of the heat exchange. Therefore, to solve these prob- lems, we will use deep mine geothermal energy to heat the wellhead by making full use of its negative pressure field and design a low-temperature water and fan-free heating system. Through numerical cal- culations we will simulate temperature fields, pressure fields and velocity fields under different air sup- ply temperatures, as well as different air supply outlet locations and varying number of radiators in the wellhead room of a new auxiliary shaft to find the proper layout and number of radiators that meet well- head anti-frost requirements from our simulation results, in order to provide guidelines for a practical engineering design. Tests on the Zhangshuanglou auxiliary shaft wellhead shows good, look promising and appear to resolve successfully the problem of high energy consumption and high pollution of well- head heating by a coal-fired boiler.