Study On Self-moving Energy Absorption And Anti-impact Roadway Support

Rockburst is one of the major disasters in coal mining.In recent years,the study found that, most of rockbursts occur in the roadway. while most of the current roadway supports are not designed from the viewpoint of anti-impact,the anti-impact ability is limited,and can’t meet the requirements of rockburst mine support.The self-moving energy absorption and anti-impact roadway support for rockburst mine is designed and innovated.And the theoretical, numerical and experimental study on energy absorption and anti-impact mechanism of rockburst roadway and the support is conducted systematically in this paper.(1) The energy absorption and anti-impact mechanism is discussed,and the dynamic model of surrounding rock support for rockburst roadway is set up.The overlying rock layer is simplified as a block composed of multiple mass blocks,the rock mass simplified as rigid body,the connection between rocks simplified as Kelvin-Voigt model, the supporting system simplified as spring and energy dissipation damper, and the initial rock is subjected to impacting load.The supporing system is a conventional supporting system,when damping is 0. And it’s a energy absorption supporting system,when damping greater than 0.(2) The high strength energy absorption support is put forward to prevent and control roadway rockburst.The dynamic model is analyzed,and the results showed that:The acceleration and displacement amplitude of roadway surrounding rock under impact loading can reduce greatly by enhancing support and improving supporting strength. Adding damping component in supporting system is conducive to quelling the vibration of surrounding rocks quickly, enhancing the anti-impact capacity of supports and improving the stability of surrounding rocks. Based on the law of conservation of energy,the theoretical derivation obtained that:the energy absorption support can enhance anti-impact property of supporting system substantially.(3) The hexagonal tubular energy absorption and anti-impact component is designed and innovated.The radial energy absorption and anti-impact component such as circular,octagonal and hexagonal components are designed. The energy absorption and anti-impact property of component is analyzed by using the theoretical, numerical and experimental research methods.And it is analyzed from the three aspects of deformation and failure law of component,the force-displacement change rule and 5 performance evaluation indexs.The results showed that:the hexagonal tubular energy absorption and anti-impact component has the advantages of stable repeatable deformation and failure mode, constant reactive force,higher stroke efficiency and irreversible energy conversion form. So it is the ideal energy absorption and anti-impact component of top beam.Also it is confirmed that the bearing capacity of energy absorption and anti-impact component is 1.1 times of support working resistance.(4) The energy absorption and anti-impact component of expanding diametral hydraulic column is designed and innovated.The axial energy absorption and anti-impact components with square crease, hexagonal crease, inside and outside overturning type and expanding diametral type are designed. The energy absorption and anti-impact property of component is analyzed by using the theoretical, numerical and experimental research methods.And it is analyzed from the three aspects of deformation and failure law of component,the force-displacement change rule and 5 performance evaluation indexs. The results showed that:the expanding diametral energy absorption and anti-impact component has the advantages of stable repeatable deformation and failure mode, constant reactive force,higher stroke efficiency,irreversible energy conversion form and deformation not inflating.So it is the ideal energy absorption and anti-impact component of hydraulic column. Also it is confirmed that the bearing capacity of expanding diametral energy absorption and anti-impact component is 1.2 times of column working resistance.(5) Self-moving energy absorption and anti-impact roadway support is designed and innovated.The self-moving energy absorption and anti-impact roadway support adopts one support type with 2 supports-2 columns. The left and right column of support are the same,and the front and back column are the same. The four-bar linkage and two hydraulic columns are used to connect the top beam and base of support.The right and left top beams and bases are connected respectively by using two regulating frame jacks.The bases of front and back frames are connected by using jack. And the top beams of front and back frames are connected by using the telescopic beam.Its main feature is that:the hydraulic column and the top beam have energy absorbing and anti-impact function,and use the front pushing-back pulling way to realize the function of support self-moving.(6) The anti-impact principle of self-moving energy absorption and anti-impact roadway support is obtained.The support anti-impact is mainly manifested in two aspects of resistance and yielding. The resistance is reflected in that the energy absorption and anti-impact component can give way,absorb energy and drop impact,when rockburst occurring.The function of giving way,energy absorption and droping impact is reflected in three aspects:On the one hand,the energy absorption and anti-impact component dissipates the impact energy of surrounding rocks;On the other hand, the constant force deformation stage of component improves the forcing situation of hydraulic column,and protects the support; On the third hand, the deformation space of energy absorption and anti-impact component provides a certain amount of energy release space,and dissipates the impact energy of surrounding rocks indirectly.The self-moving energy absorption and anti-impact roadway support is designed from the viewpoint of anti-impact.It has a stronger supporting strength and anti-impact abilities.The new type of support to prevent and control rockburst can meet the requirements of roadway anti-impact support for rockburst mine.All these have great economic and theoretical significances for safety and high-efficient mining of coal mine.