Application Of Modified Coal In The Mine Overloaded Roads

AbstractThe overload phenomenon of coal vehicle in Huainan Mining is serious,which leads to the damage of pavement structure and the decrease of service life.Coal gangue is a kind of rock and solid waste which is associated with coal during the process of formation of coal,which has been the most industrial solid waste. Therefore,the modified method of coal gangue using lime,ash and cement is put forward to instead of the routine martial of the base and subbase of road,which can satisfy the the overload traffic condition in the road of mining. The change law of subgrade equivalent modulus of resilience when the subgrade is handled with modified coal gangue and the change law of deflection value with the thickness of modified coal gangue subbase and modulus are obtained taking the combination method of theoretical calculation,the test and the numerical simulation.The physical and mechanical parameters of modified coal gangue of different weathering degree is obtained with the modified experiment,as the result of that,the finite element model is established and the overload road in mining is designed under the equivalent condition of deflection and stress.The main achievements are as follows:(1) The subgrade equivalent modulus of resilience increases with the increase of thickness of modified coal gangue and the modulus of modified coal gangue,but the increase of the subgrade eq uivalent modulus is gradually slow with the increase of modulus of modified coal gangue.The combination of the thickness and modulus of modified coal gangue is needed when the subgrade equivalent modulus is increased to 120MPa、150MPa、180MPa and 200 MPa.The combination of the thickness and modulus of modified coal gangue with different values of subgrade equivalent modulus is designed under the conditions of equivalent deflection and different overloading.(2) The 7d unconfined compressive strength of modified coal gangue is presented by the experiment which can satisfy the filling material requirements of the layer subbase in the overloading road.The development of the early strength of cement stabilized coal gangue is rapid and gradually slow down with the growth of time,but the development of the early strength of lime and fly-ash stabilized coal gangue is slower,the development of the late strength of which is faster.The relationship of The subgrade equivalent modulus and the thickness of the layer using modified coal gangue in different weathering degrees is obtained,at the same time the cohesive force and internal friction angle of that is obtained taking the splitting test,which can provide the necessary physical parameters for the finite element analysis.(3) Using the finite element software ANSYS, the bending tensile stress of each layer is analyzed using the modified coal gangue in different weathering degrees as the subbase under the condition of deflection equivalent.The results show that the bending tensile stress of each layer of the optimized road is less than the original road.The maximum load of road construction under the different combinations of thickness and modulus is presented when the subgrade equivalent mod ulus is increased.(4) The design principle of overloading road in mining under different wheel pressure is put forward through the finite element analysis.