Study On Controlling Technology Of Surrounding Rock Of The Large Section Rock Roadway In Weakly Cemented Stratum In Dananhu No.5 Coal Mine

The weakly cemented strata in the western mining area have poor cementation,low self-strength,and are prone to mud disintegration when encountering water.The roadway support is particularly difficult,which has become an important technical factor restricting the safe and efficient production of western coal mines.Based on the engineering background of the horizontal auxiliary transport cross-cut at +170 m level of the Dananhu No.5 Coal Mine,this thesis adopts the comprehensive research methods of theoretical calculation,laboratory experiments,numerical simulation and corresponding on-site measurements to study the surrounding rock control technology of large section rock roadway under the condition of weakly cemented stratum.The main research results are as follows:(1)By means of on-site investigation and access to facts and figures,etc.,the detailed geological conditions of the horizontal auxiliary transport cross-cut at +170 m level of the Dananhu No.5 Coal Mine were accessed,and the physical and mechanical properties of weakly cemented surrounding rock of horizontal auxiliary transport crosscut were studied thoroughly.It is not tough to discover from the research results that a numerous amount of clay minerals with water absorption and swelling exist in the rock,and there are a large amount of gaps between the rock grains,which are extremely easy to muddied and disintegrated after water contact,and making it more challenging to control the surrounding rock.(2)By analyzing the deformation and destruction features of the roadway of the horizontal auxiliary transport cross-cut at +170 m level with roof water,it shows that the roof water is a significant factor which affecting the carrying capacity and the stability of surrounding rock.The original support scheme cannot provide active support force to the roadway,so that the deformation and destruction of the roadway are acute,the displacement of the roof,side and floor of the roadway are 240 mm,256 mm and 82 mm,obviously,the support scheme needs to be improved.(3)The joint support of the anchor(cable)is adopted to stopping the surrounding rock from deforming and damaging.The surrounding rock structure of roadway with water-enriched roof has been analyzed,diverse factors affecting the stability of roadway are also summarized,on this basis,the several control countermeasures of the roadway are put forward.Considering the geological conditions(water content,lithology)and deformation and of surrounding rocks of the +170 m horizontal auxiliary transportation cross-section,the roadway is supported in sections,and the roadway is divided into class ? Water-enriched Roof Roadway,class ? Water-enriched Roof Roadway and floor heave roadway.(4)Through the theoretical calculation,the roadway support parameters values range is preliminarily accessed,and then several groups of support schemes are proposed within this range,then,the support effects of different schemes are contrasted by numerical simulation software,finally determining the final surrounding rock segmental support scheme,together with reasonable roof water release measures,to form the horizontal auxiliary transport cross-cut at +170 m level surrounding rock segmental support scheme.(5)By conducting industrial tests in the field,Periodic monitoring was carried out in the roadway.The actual results showed that the peak value surrounding rock loosening circle is 1.99 m,the deformation and destruction of the roadway are acute,the displacement of the roof,side and floor of the roadway are 110 mm,126 mm and27 mm.The anchor rod(cable)provided timely and active support for the surrounding rock,which greatly diminished the deformation of surrounding rock and exceedingly guarantee d the long-term safety and stability of the roadway.This paper has 51 figures,10 tables and 88 references.