抑制煤矿砂岩顶板岩石摩擦火花和升温

Control on rock friction sparks and heating-up of sandstone roof in a coal mine

为预防和控制采空区砂岩顶板跨落岩石摩擦火花和高温引发的瓦斯事故,采用电动摩擦试验装置,进行了岩石自然和饱水状态下摩擦打火和表面升温的模拟研究。结果表明:顶板跨落时岩石相互摩擦产生火花且表面升温,升温值与岩石质量、跨落高度之间呈正相关关系,与岩石质量满足三次幂级的函数关系,饱水岩石摩擦产生火花的频率、强度及表面升温值较自然状态下有明显的降低。本文通过注水岩石试件试验,为减少岩石碰撞火花和降低岩石表面温升值提供了可靠的试验依据,为防止因顶板跨落而诱发瓦斯灾害提供了有效的技术措施。

A simulated experiment on rock friction sparks and surface heating-up was conducted in natural and water-saturated conditions using a motor-driven friction apparatus. The purpose of the experiment is to understand and prevent gas hazard caused by friction sparks and heating-up caused by caving rocks from sandstone roof. The experimental results show that there are sparks and heating-up on the rock surface due to rock friction. The temperature increase at rock surface is positively correlated with rock mass and caving height. In particular, it is proportional to the third power of rock mass. It is evident that the frequency and strength of rock friction sparks and surface heating-up value in water-saturated condition were much lower than that in natural condition. The frequency of sparks and rock surface heating-up might be reduced by water flooding, thereby the objective of reducing and eliminating gas hazard in goaf caused by roof caving could be achieved. The results in experiment on water-saturated rock samples for reducing rock friction sparks and heating-up are also presented.