Correlation Analysis Of Roadway Surrounding Rock Stability And Thickness Determination Of Surrounding Rock Loose Zone

With the continuous development of society,in order to meet the social needs,resource exploitation has entered the deep.Deep mining is more difficult than shallow mining,and reliable support theory and support technology are required for safe mining under high ground stress.In the roadway support theory,the surrounding rock loose zone theory proposed by Dong Fangting is widely recognized.The loose zone theory classifies the surrounding rock according to the thickness of the loose zone,which is conducive to the development of underground engineering.The mining depth of the two Huaihe mining areas is generally more than 800 m,and the thickness of the loose circle is generally more than 150 cm.Whether the loose circle theory under the big loose circle has the same reliability as that of the small and medium-sized loose circle,in order to serve the economic development of the two Huaihe mining areas,it is of great significance to study the reliability of the loose circle theory.This paper studies the reliability of the big loose circle theory through the combination of numerical simulation and field test,At the same time,the relationship between surrounding rock loose zone and displacement gradient is studied.This paper takes the straight wall semi-circular arch roadway in the deep fracture zone of Zhuxian Mine in Suzhou as an example to carry out the following research:(1)Carry out field experiments,install instruments and equipment on site,use multi-point displacement meter to collect the displacement at different depths from the roadway surface within a certain time,observe the degree of broken swelling of surrounding rock,and measure the loose circle of surrounding rock.(2)The displacement gradient is calculated from the measured data of surrounding rock displacement distribution in time and space,and the relationship between the displacement gradient and the loose zone is observed.(3)The numerical simulation software is mainly used to simulate the roadway with original rock stress greater than 9MPa under different lithology and different support conditions,calculate the thickness of surrounding rock loose zone and roadway stability theoretically,analyze the reliability of loose zone theory under large loose zone,and analyze the relationship between loose zone thickness and displacement gradient.Combined with field test and numerical simulation,the reliability conclusion of loose ring theory under large loose ring and the new method of loose ring thickness measurement are obtained,which provides guidance for the actual construction.Figure[54]table[18]reference[45]...