Study On Support Technology For South Wing Roadway Of Geologic Abnormal Body In Guqiao

With the increasing depth of coal mining, the stress increase, the engineering geological conditions become more complex. Supporting problem of deep soft rock roadway has become a technical problem of deep coal mining. The-780m belt conveyor roadway in Guqiao south wing need through a geological anomalous body which is constituted by the maximum gap140m, width670m F108-1～F114-1faults during construction. Surrounding rock of roadway is loose and broken. The water pressure is big. Excavation and support become extremely difficult. Therefore, according to the engineering background, this paper take the support of southern section of belt conveyor roadway (two) in Guqiao south wing which has three kinds of poor geological surrounding rock conditions for study.On the basis of state support theory of soft roadway, according to the three complex geological conditions in southern section of belt conveyor roadway(two), this paper point out that information construction and combined support technology should be adopted. Then, this paper analyze the type of surrounding rock of roadway according to its drilling geological section. According to the three different kinds of geological conditions, this paper put forward to3kinds of different support scheme. When the tunnel is located in sandstone, the anchor+U-shaped steel+backfill grouting is adopted;when the tunnel is located in the F108fault broken zone, pre-grouting+anchor+U-shaped steel+backfill grouting is adopted; when the tunnel is located in mudstone, sandy mudstone and coal interbeds section, on the basis of anchor+U-Shaped steel+backfill grouting, construction of inverted arch, which forms a closed force structure. And using numerical analysis software FLAC3D, part of the roadway support parameters are optimized, the stability of surrounding rock in different support parameters are Simulated.The optimization results are given. In order to obtain the mechanical properties of the circular U36steel brackets, we test its mechanical properties. The results show that, it has high bearing capacity, it can meet the requirements of the roadway. In actual construction, pre-grouting was employed to reinforce surrounding rock of roadway which cross broken fault zone, we drill core on the surrounding rock and analyze the reinforcement effect. The result shows that pre-grouting successfully filled the rock fissure. It plays a role of sealing water and reinforce the surrounding rock. It ensures the safety of construction.Finally, the field test shows that after taken these combined support technology, the deformation of southern section of belt conveyor roadway (two) become stability. It has achieved the desired effect. At present, the roadway has been put into use. This support technology can provide reference for similar roadway in future.