Study On The Damnification And Failure Laws Of The Floor In Fully Mechanized Caving Face

Along with the continuous development in coal industry, coal resource exploitation turns from simple and rough pattern into precise and mechanized one. After servel revolutions in coal industry in China, coal exploitation has changed into big coalfield, large wells and high yield model gradually. With the convienience brought by mechanized mining, majority coal with lower buried depth has been exploited, and that with deeper buried depth has been exploited already in most coal mines. However, the exploitation extension not only involves higher ground stress owing to the increase of buried depth, but also concerns with higher temperature, higher pressure and other unfavourable restricting factors. The most serious problem is the threat of confined water to safety production and personal safety, so how to define and prevent water inrush has become an inevitable problem for mining personnels in modern times. Based on the geographical model of Yitang coal mine, theoretical analysis, engineering analogy, field measurement and numerical simulation are combined to study the failure regularity of floor and the failure regularity of confined upflowing water zone, and the main research results are as follow:(1) Reasons of water inrush of floor have been studied, that is, water isolating ability of floor and even the whole strata is lost under the coupling effect of damage to mining and confined water of floor.(2)The calculation and analysis of empirical forlula show that it is not the single factor but several factors that affect the failure depth of floor;(3)Field measurement was applied to keep a continuous and dynamic monitoring on the floor strata in the 100502 working face of Yitang coal mine, and the failure depths of floor under the damage to mining were obtained;(4)In view of fluid-solid coupling effect, the numerical simulation software FLAC3 D was used to inquiry the failure laws of floor with the damage to mining under the effect of servel different factors and analyze rising height of confined upflowing water zone with linear regression, correspondingly, calculation formula were also proposed.