Study On Deformation Law And Control Technology Of Weak Cemented Surrounding Rock Eroded By Alkali Water In Dananhu No.7mine

Themining of weakly cemented coalmeasure strata in westernmining area of China has broughtmany technical problems,among which themost complex one is the surrounding rock control of weakly cemented soft rock roadway under water rich conditions,especially under alkaline water rich conditions.The key to solve this problem is to reveal the deformation characteristics and laws of weakly cemented surrounding rock roadway under alkaline water environment,and put forward reasonable surrounding rock support scheme,So as to realize the safety and stability of the roadway in the process ofmining.Based on the hydrogeological investigation of weakly cemented strata in the westernmining area,themain research results are as follows:(1)According to the deformation law of surrounding rock before and after alkali water erosion and before and after support,the deformation law of surrounding rock with alkali water and without support,with support and without alkali water,with alkali water and with support under p H value of 7,9 and 11 is obtained by numerical simulation analysis.It is concluded that alkali water erosion weakens the strength of surrounding rock of roadway roof significantly,and support improves the stress environment of surrounding rock of roadway obviously.(2)The secondary development of FLAC3 D simulation software is carried out by using fish statement,and the creepmodel under alkaline water is considered.Based on the constitutivemodel,the deformation and failure laws of alkaline water weakly cemented roadway under different support schemes and creep effect are compared and analyzed,and the optimized support scheme is put forward.(3)The optimizedmethod is applied to the actual 11701 return air roadway formine pressuremonitoring and analysis.Themonitoring contents include:deformationmonitoring of roadway surrounding rock,stressmonitoring of bolt(cable)support,and crackmonitoring of roadway surrounding rock.The displacement of the roof,the deformation of the two sides,the floor heave,the axial load of the anchor,the axial load of the anchor cable and the separation of the surrounding rock in the anchorage zone are obtained.Themonitoring results verify the rationality and safety of the support scheme.This paper has 134 pictures,30 tables and 68 references.