Pillar Stability Study On The Room And Pillar Mining Of Liaoyang Wendong Gypsum Mine

Gypsum mineral resources are abundant in our country,its reserves can reach 57.6 billion tons.As a result of the gypsum application field widely and its economic value is high,so the gypsum mine exploitation scale is increasing.In our country,the gypsum mine are mainly composed of room and pillar mining,this method can effectively control ground movement and deformation caused by underground mining and destruction,it also can protect the safety of ground buildings and facilities,so,to guarantee the stability of pillar is an important part of the room and pillar mining.This article takes Liaoyang wendong gypsum mine as engineering examples,the engineering example to carried on the thorough analysis of the study area,for example,the geological mining conditions,hydrogeology,engineering geology characteristic and so on.Through the indoor experiment method,the Softening performance and dissolution rate of Gypsum ore under hydrostatic condition were studied.By the method of limit equilibrium theory,the reasonable size of room and pillar mining stope and pillar is designed,and the pillars of stability in-depth analysis.Using numerical simulation software FLAC3 D,the wendong gypsum mine under the condition of different sizes of room and pillar and stall on the study of numerical simulation,We obtained the safety factor of the pillar,and the relationship between the size of the column and the safety factor is analyzed.Basically achieved the following results:?1?In Liaoyang wengdong text east gypsum mine ore in different periods of flooding the compressive strength and softening performance experiment study,to obtain the compressive strength and softening coefficient of gypsum ore with the changing rule of the immersion time: In immersion time 0h gypsum ore uniaxial compressive strength of 90.7 MPa;Immersion time in the 72 h to 1880 h interval,gypsum ore uniaxial compressive strength is reduced gradually,and shows that gypsum ore in softening occur under the action of water,and also the softening coefficient decreases with the growth of time;After soaking time 1880 h,gypsum ore of uniaxial compressive strength gradually but steadily in 78 MPa,softening coefficient of 0.86.?2?In Liaoyang wengdong text east gypsum mine ore in different periods of flooding the corrosion speed of experiment study,obtain the gypsum mineral dissolution velocity rule: Gypsum specimen is influenced by water dissolution average 15 days of quality is 0.8g,after 4 months,the dissolution of total mass with an average of 6.19 g,the rate of dissolution is 0.051g/d.Therefore,gypsum specimen was completely dissolution need to 26 years,corrosion speed slower,smaller influence on the stability of a pillar.?3?Combination of Liaoyang wengdong text east gypsum mine geological and mining technical conditions analysis,summary text east gypsum mine room and pillar mining pillar of the influence factors of instability has pillar strength,poor geological conditions,aspect ratio,load the overburden strata,stope structure size,etc.Pillar type of buckling is cut along the slip surface damage,destroy,pressure shear damage and destruction.?4?By material yanliang hypothesis mechanics theory,and combining the Liaoyang wengdong text gypsum mine actual production conditions,an integrated determine room and pillar mining of the ore room width is 8m,pillar width is not less than 4m.And based on limit equilibrium theory,the pillar width is 4m,6m,8m,10 m and 12 m pillar stability is analyzed under the condition of mining method,the results show that the "8 m,6 m" scheme,pillar in a stable state.?5?By FLAC^3D software to Liaoyang wengdong text east gypsum and stall has carried on the numerical simulation research,the results show that the mining 8m,6m "mining scheme of pillar is in stable condition,and with the limit equilibrium theory of pillar stability calculation results were analyzed,concluded that" leave 8m,6m "room and pillar mining scheme is feasible.