Study On The Stability Of Deep Mining Roadway Of No. 34 Ore Body In Fengliushan Mining Section Of Gejiu

In the No.34 orebody of Gejiu Fengliushan mining section,the research object of this paper,due to the development of joints and fissures in the granite alteration zone and poor mechanical properties,the surrounding rock of the roadway generally appears large deformation,which affects the stability of the roadway and safe production in the mining area.Posed a threat.In order to understand the specific engineering geological problems of the roadways in the study area,this paper selects three different middlesection roadways in the study area and conducts on-site investigations on the geological conditions and construction deformations of the roadways.By sampling different rock groups and analyzing the physical and mechanical parameters of the rock mass,the surrounding rock of the roadway in the study area is classified according to the "Engineering Rock Mass Classification Standard" and the "Water Conservancy and Hydropower Engineering Geological Survey Code" as the classification standards,and finally the Flac3 D software is used to perform the numerical value.Simulation,comparing the classification results,simulation results with the on-site situation,and draw the following conclusions:(1)According to the results of the field survey,the statistics are compiled and then drawn into a graph for analysis.It can be seen that the surrounding rock of the roadway generally has more joints and cracks and less filling,and the inclination of the joints is mostly concentrated above 60°.The stability of the roadway is poor.(2)By sampling in the study area and analyzing the rock physical and mechanical parameters,it can be found that the mechanical properties of marble are better under the same degree of weathering,and the mechanical properties of strongly weathered granite are the worst.(3)Two types of surrounding rock classification methods are used to classify the surrounding rock of the roadway.After comparing the classification results according to the standard with the actual situation on the site,the classification standards of the《Engineering Rock Mass Classification Standard》 are basically reliable,while the《Water Conservancy and Hydropower Engineering Geological Survey Specifications》The classification result for the slightly weathered granite group does not match the actual situation of the field.It is relatively stable without reinforcement,and the amount of deformation is small.The classification results show that in the three roadways,the slightly weathered granite group and the fresh granite group are relatively stable without support,and the other rock groups are unstable and require a certain degree of support.(4)Use Rhino software to build a roadway model based on the design drawings and site survey results,and import it into the Flac3 D software.The overall calculation results are more consistent with the site conditions and correspond to the classification results.The penetration of the plastic zone of the roadway means that the surrounding rock is damaged under the in-situ stress operation.The simulation results show that in the three roadways,the slightly weathered rock group and the fresh granite group have no plastic zone,which is relatively stable and does not require support.The other rock groups have plastic zones,Instability requires the use of support methods to maintain the stability of the surrounding rock of the roadway.(5)According to the displacement cloud map of the strongly weathered granite roadway,it can be found that the maximum displacement occurs on the rock walls on the left and right sides of the roadway,and the bottom plate also has a large displacement.The arched roof of the roadway generally has a small displacement,so In the support,priority should be given to supporting rock walls and bottom plates.(6)Analyzing the displacement curves of different rock groups in the same roadway,it can be concluded that the greater the weathering degree of the same kind of surrounding rock,the easier it is to produce unstable deformation.Comparing the overall displacement cloud diagrams of the three roadways,it can be concluded that the roadway displacement decreases as the buried depth decreases.Through the above conclusions,the deformation laws of different middle sections of the roadway in No.34 ore body can be grasped,and suggestions can be provided for the selection of suitable support positions for existing roadways and the selection of suitable support time and strength for newly opened roadways,so as to avoid further strain softening and weakening of surrounding rock.In order to improve the efficiency of production and ensure the safety of roadway construction and operation.