Construction Mechanical Behavior of Surrounding Rock and Supporting Structure of Tunnel in Complex Coal Seam Group
When the tunnel is excavated through the inclined coal measure strata,it is easy to collapse due to the excessive deformation of the surrounding rock,and in severe cases,it will induce secondary disasters such as gas outbursts and explosions.To ensure the safe and efficient construction of the coal-rich tunnel,this paper takes the Tianchengba tunnel as the background project and uses the numerical analysis software FLAC3D combined with the field monitoring method to explore the surrounding rock variation law of the complex coal seam group under five thicknesses and the applicability of the construction method.The results show these as follows.With the increase of the thickness of the coal seam,the deformation of the surrounding rock of the coal seam group is getting larger and larger,and the deformation reaches the peak at about 50 m of the excavation steps.Comparing and analyzing the deformation of surrounding rock and the initial support stress of five groups of coal seams under the two construction methods,the three-step reserved core soil method can effectively reduce the deformation of surrounding rock compared with the three-step method.Comparing the simulation results of three-bench reserved core soil excavation with the field-measured data,the difference rates of the vault and inverted arch data are 5.69％and 5.68％respectively,which are within the allowable range.This shows that the construction of the three-step reserved core soil method can effectively control the disturbance of the tunnel construction to the surrounding rock of the tunnel,and can ensure the safe and efficient excavation of the tunnel in the complex coal seam group.
complicated coal seamdifferent thicknessFLAC3Dsurrounding rock reformationconstruction method
万方数据
维普
