Study On The Deformation And Failure Mechanism Of Surrounding Rock And Zoning Support Technology In Roadway Sensitive To Stress Disturbance

More fault structures will arise in roadway excavation in complicated coal minegeological conditions, resulting in dramatic weakening of roadway surrounding rockstrength and integrity and the change of stress state. Affected by fault structures, afterexcavation, surround rock of roof and floor is under conditions of relatively highhorizontal stress and surround rock of is under conditions of relatively high vertical stress,compared to that without the effects of fault structures. Meanwhile, the integrity andstrength of roadway surrounding rock is weakened as well. In the period of roadwayexcavation and service, large conformation or even roof fall take place in surroundingrock, severely affecting the normal and safe production of coal mine. Consequently, it isof great scientific and engineering significance to conduct research on the deformationand failure mechanism of surrounding rock and on its support technology in zone of faultstructures.This present paper takes haulage entry6163in Qidong coal mine as research objects,on the basis of field investigating roadway engineering geological characteristics andanalysing conformation and failure factors of roadway surrounding rock, proposing theconception of roadway sensitive to stress disturbance and explaining its implication andfeatures as well. Experiments have been conducted to test the mechanical characters andcomponents of roadway surrounding rock. With the analysis of microstructure, fieldmeasurements, theoretical analysis of fracture evolution law and conformation law ofroad surrounding rock and numerical simulation, this paper studied the impact faultstructures have on the roadway surrounding rock stress state in the process of roadwaypuncturing faults. The extent of effect fault structures have on the roadway surroundingrock stress state is approximately25～27m. The horizontal stress of roadway roof andfloor and vertical stress of roadway sidewall augment dramatically as a result of the faultstructures, compared with that in normal region, which again result in the severedeformation of roadway surrounding rock. Based on what mentioned above, this paperproposed Zoning support mechanism and technology in roadway sensitive to stressdisturbance, regionalising roadway sensitive to stress in the excavation direction. Theentire region is divided into two categories. The regions within the range of30m at eitherside of fault structures are called fault structure areas, and the rest are called normal areas.Corresponding support parameters and schemes are adopted to ensure the stability of roadway surrounding rock in both fault structure areas and normal areas. By virtue ofnumerical simulation software FLAC3D, this paper optimized the length, diameter ofsidewall bolt and array spacing of bolt and anchor cable, matching designed the pre-stressed force of bolt and anchor cable, and confirmed Zoning support scheme andparameters in roadway sensitive to stress disturbance. Field experiment indicatesroadway conformation has been controlled effectively and favorable economic andtechnological benefits have been achieved as well, providing useful lessons for studies onsurrounding rock control of mining roadway in similar conditions.