Study On Deformation Of Soft Rock Roadway Based On Surrounding Rock Hydrodynamics

Shanghai Miao Mining Area has abundant coal resources,deep buried resources and complex mining conditions.The large deformation disaster of deep soft rock roadway has become an important technical problem hindering the mining of deep coal resources.Combined with the engineering practice experience of soft rock roadway at home and abroad,the high stress effect and the hydraulic characteristics of soft rock itself will be the key factors affecting the composite deformation of roadway.This paper mainly studies the deformation of the transport roadway in Yingjun No.1 Mine of Shanghai Miao Mining Area by using the method of similar material simulation.After comparing the theoretical calculation results and similar simulation results,the paper makes comparative analysis and mutual verification,and then obtains the deformation law of the soft rock roadway based on the surrounding rock hydraulics conditions.Based on the analysis of rock composition,it is concluded that the roof and floor of coal seam in Shanghai Miao Mining Area are mainly sandstone and sandy mudstone,and its clay content is high,showing the characteristics of hard rock without water,and rapidly disintegrating mudstone after water contact.Through the study of water absorption and expansion of rock strata,it is concluded that besides the forceful action of water on rock strata,the softening of rock occurs after water encounter due to the influence of hydrophilic minerals,homogeneous structure and cementation degree of rock.In the process of numerical calculation,the relationship between the deformation of roadway and time and the displacement of roadway under different water-bearing conditions are obtained without considering the accelerated creep of soft rock.Through practical engineering experience,it is concluded that after 30 days,the creep of surrounding rock has entered a stable state.When the surface water content reaches saturation,the maximum deformation of roadway corresponds to 622 mm.Through similar simulation,the creep of roadway roof is studied.It is concluded that themagnitude of load has a great influence on the creep of roadway.The magnitude of load determines the speed of roadway deformation and the degree of damage.On the other hand,for this kind of soft rock in Shanghai Miao Mining Area,the water content also determines the speed and speed of roadway deformation.Through comparative experiments,it is concluded that the influence of water content on soft rock roadway is stronger than that of load.Similar simulation experiments on the first mining face show that soft rock shows similar properties to clay after absorbing water.In the course of roadway deformation,the roof strata deformation is the fastest,and the roof strata are less affected by the roof damage and control.With the increase of excavation time,the strata above the roof deform synchronously with the roof,and the roof strata eventually show the same deformation.The maximum deformation of roadway before collapse occurs on the 12 th day,and the maximum displacement of roadway is1.34 m.Compared with the actual production,the deformation of roadway has a certain difference with the experiment due to the supporting effect,but the variation of the roof of surrounding rock with time is basically in line.Therefore,the law studied in this paper can provide theoretical support for the mining of similar working face in mine.