Study On Instability Mechanism And Controlling Technology Of Soft Rock Roadway With High Stressed

The soft rock roadway is the focus of the research on the roadway support in today mining scholars.Due to soft rock roadway with high stress its own characteristics of high stress environment,broken structure and low strength,lead to roadway deformation is serious,repair is difficult and maintenance cost is high,It is a problem to be solved urgently to explore the correct deformation mechanism and control technology of the soft rock roadway with high stress.Therefore,this paper take Quandian coal mine 22 mining area of track down as the engineering background,integrated use theoretical analysis,numerical simulation,laboratory test and industrial test methods to systematic research the deformation instability mechanism of high stress soft rock roadway under rock damage condition as well as quantitative yieldable supporting technology of surrounding rock,made the main innovative achievements are as follows:?1?Through the monitoring of the surrounding rock loose circle and surface displacement,given the deformation regularity of haulage-dip surrounding rocks;based on the analysis of the original supporting scheme,combination with roadway damage characteristics,find out the existing problems of the mine original support.?2?Based on the conventional three axis test and pre-peak unloading confining pressure tests,establishes the relationships of the high stress soft rock between plastic parameters and rock post-peak strength attenuation parameters,such as deformation parameters?elastic modulus E?,strength parameters?cohesion c,internal friction angle ??and dilatancy effect?dilatancy angle ??,build the large deformation constitutive model.?3?Through the substitution and derivation the plastic shear strain ?_p and the plastic parameter ?^ps,embeds the large deformation constitutive model after replaced plastic parameters into FLAC^3D numerical calculation software,using this model to study the surrounding rock deformation mechanism of haulage-dip under the different confining pressure and support strength.?4?Put forward the supporting concept of "quantitative yieldable",give out the supporting method such as “yielding under the strength condition of multi-level,back filling for increased resistance,compression under the high strength reticulated shell”,the theoretical calculation based on the reservation yielding space,by using FLAC^3D numerical simulation software,this paper studied haulage-dip surrounding rock deformation regularity under combination of different sizes of yielding-layer and U steel supports,and determined a reasonable supporting parameters.?5?The research results will be applied to the Quandian coal mine 22 mining area of haulage-dip,and the corresponding mine pressure is monitored.The monitoring results indicat that the vertical and horizontal displacement maximum value are 135.6mm and 103.3mm respectively,within the controllable range,it show that the “cable anchor + yielding-layer +U steel supports” composed of quantitative yieldable support system is favorable to control the harmful deformation of surrounding rock.