Research About The Rockmass Classification And Stability Evaluation In Underground Stope In Jiaojia Gold Mine

Quality classification and stability evaluation of rock mass are important contents of underground engineering.With the development of national economic construction,there are more and more large underground rock mass engineering.In mining engineering,how to reasonably measure rock mass quality classification and stability evaluation and how to reveal evolvement rule of rock mass stability are directly related to safe and efficient mining of mines.This thesis is based on the collaborative project of northeastern university and Jiaojia gold mine focusing on comprehensive technology research on high-efficient mining of gentledip broken orebody.The main research contents and conclusions of this thesis mainly includeseveral aspects as following:(1)Baseing on rock mass joint and cracks non-contact collection system and artificialsurvey,information of rock mass joint and cracks in test stope were extracted.Thus,a largenumber of detailed and reliable data were acquired.(2)RQD is an important indicator of rock mass quality classification.Considering theeffects of scale and space on the value of RQD,three-dimensional fracture networksimulation was introduced into rock mass quality classification as acquisition method of RQD.Through practical application in Jiaojia gold mine prove that the RQD values are accuratelyacquired,engineering quantity is reduced,manpower and material resources are economizedand efficiency is increased by three-dimensional fracture network simulation.(3)Historical data samples were learned and predicted evolutionary using BP neuralnetwork.Mathews Chart was optimized,thus,stable region,potential instability region and caved region were redefined.Division of small hydraulic radius with low stability coefficient and large hydraulic radius with large stability coefficient is close to the real situation.(4)At last stope structure parameters were optimized and supporting measures werestudied based on classification of rock masses in the stope of Jiaojia gold mine and estimationof stability.When recovery approach span is less than 8 m,the stope can maintain stable.On the premise of safety,stope production capacity can maximize and safe and efficient mining of mines is realized.