The Research Of The Floor Heave Mechanism And Control Technology In Deep Thick Mudstone Floor Roadway

For thick mudstone roadway floor, because the traditional maintenance methods tend to be concentrated to roof and two help, lack of attention to floor become the roadway support in weak point, prone to serious floor heave, then two sides and roof have lost the basis for stable, will inevitably occur deformation and destruction, and ultimately the formation of deformation and failure of the tunnel section, often in a damage- Repair- destroy vicious circle of healing. The comprehensive application of theoretical analysis, laboratory test, numerical simulation with FLAC^3D, industrial test was employed in the study, in jiangjiahe coal mine mining area east return air roadway as engineering background, a detailed analysis of the roadway surrounding rock composition and characteristics, screened bottom heave of influencing factors,and puts forward the treating method for the. The main research contents and results are as follows:1)The return air roadway geological condition and failure form. The rock mass is mainly sandy mudstone, coal and mudstone in the above 4.7 m range, and the bottom6 m is dark gray mudstone or carbonaceous mudstone, and 6m¹0m is an Al soil mudstone with low strength. Return air roadway length of 1500 m. The bottom heave amount more than 1m lanes with a total of up to 900 m, local maximum floor heave super 2.2M, roof damage in the form of performance shedding vault shotcrete layer a large crack, vault by extrusion shear damage net and top arch and V failure.2)Analyzes the main factors affecting the floor heave of roadway and lithology.From the angle of micro mineral component characteristics of rock mineral composition, physical and mechanical properties, water physical properties, swelling were studied. By the results of X-ray diffraction and transmission electron microscope（SEM） analysis shows that air return roadway top floor rock main component is kaolinite and illite \ mixture of Mongolian, and containing a small amount of montmorillonite, the contents of which were 59%, 38% and 3%. In case of the condition of the water will be rapid expansion and mud. Roadway floor heave is mainly affected by the roadway surrounding rock characteristics, stress, hydraulic effect, existing branch support form and ZF1402 working face of the mining etc.factor influence, belonging to the composite type of floor heave.3)According to the theory of the limit self stable equilibrium of the roadway, the control scheme of the roadway is established. Based on the limit equilibrium ofroadway arch domain branch support, treatment top to govern the help and treatment help to govern the floor, with the Department is key of soft rock roadway supporting principle, combined with the return air roadway floor heave characteristics, determine the adopted key on the roadway floor of powerful anchor support with grouting reinforcement scheme, also on two help and roof bolting and grouting reinforcement,forming bottom two help- the domain of roof control structure, make full use of the surrounding rock of self stability, reduce the instability region and make it into a stable region, which uses high performance anchor belt net and cable and grouting reinforcement combined support support technology.4)Using FLAC^3D to simulate the effect of different support parameters. Using FLAC^3D numerical simulation software to the original branch support design, only anchor cable reinforcement, only grouting reinforcement, anchor injection combined remediation four schemes and supporting effect of numerical simulation are determined by the combined bolt grouting reinforcement scheme, can be effective reinforcement of roadway, effectively reduce the surrounding rock deformation,reduce the initial deformation rate, and earnestly safeguard the stability of the surrounding rock of roadway.5) Field applications in jiangjiahe coal mine air return roadway show that deformation and failure of roadway has been effectively controlled, effectively safeguarding the stability of the tunnel.