Response Of Roadway Of The Floor Heave Control With Borehole Pressure Relief And Prestressed Grouting Anchor Cable Under Static And Dynamic Load

It is typical problem that the floor heave effect the normal production of roadway.This research method has been developed about the problem of floor by domestic and foreign research scholars under static load,but there are very few on the dynamic load,especially roadway will often encounter drilling blasting,shock pressure and other dynamic disturbances.In this paper,the numerical software FLAC3 D is used to study the stress wave propagation and dynamic response of floor displacement,vibration velocity,vibration acceleration and so on of roadway the roadway treated by borehole pressure relief and prestressed grouting anchor under dynamic and static load,and explore the dynamic response of the prestressed grouting cable at floor bottom.The results show:(1)Under static load,the maximum floor displacement of roadway by prestressed grouting anchor cable and drilling pressure relief decreases by 41.9% and 35.4% respectively.The floor plastic zone of tension and shear is gone after the treatment of grouting anchor cable,the floor plastic zone of tension and shear decreases after the treatment of pressure relief hole.The minimum principal stress of roadway by prestressed anchor cable is increasing,and the minimum principal stress of pressure relief hole is decreasing.The treatment effect of roadway by prestressed grouting anchor cable is better than that of roadway by borehole pressure relief under static load.(2)Under the bottom of the dynamic load,the stress peak of roadway with prestressed grouting anchor cable on the floor is less than that of the original roadway and roadways controlled by borehole pressure relief in the anchor reinforcement area.Displacement increment of the original roadway and roadway with pressure relief hole is close relatively under the dynamic load,and displacement increment of roadway with prestressed grouting anchor cable is significantly less than that of the other two cases;The floor is the most violent place,and the peak value vibration velocity acceleration of roadway with prestressed grouting anchor cable is maximum,the second is the roadway with pressure relief hole,the original roadway is minimal.The new shearing yield and tensile-shearing yield is generated at the bottom corner of the model and at about 2 m from the bottom of the model.Under the action of dynamic load at the bottom,the stress of roadway with prestressed anchor cable increases,and the stress of roadway with pressure relief hole decreases.(3)The axial tensile stress and the shear stress of cement paste will fluctuate under the plane stress waves.The axial tension stress amplitude of the intermediate anchor cable is larger than the others,the three elements closer to the anchor head are more obvious.The peak value of the shear stress of the cement slurry of the intermediate anchor cable is smaller than the others,the height of the first wave crest of anchor cable unit increases firstly and then decreases from anchor head to anchor end,and the most large height position of the first peak is also different.(4)Under the dynamic load at the right side,displacement increment of floor with the original roadway and pressure relief hole is close relatively,and the displacement increment of right bottom of the three kinds of support forms is larger than that of the left.The right vibration velocity of roadway with the three kinds of support forms is larger than that of other part obviously.Roof acceleration of roadway of three kinds of supports are the maximum,and roof negative acceleration of roadway with pressure relief hole is maximum,the second is roadway with prestressed grouting anchor cable,the original roadway is minimal.The stress of roadway with the pressure relief hole is reduced,and the stress of roadway with prestressed grouting anchor cable increases.