| With the development of economic construction in various countries,more and more excavation of deep rock mass engineering is involved.In the process of excavation in high stress area,the spatial environment of rock mass is changed and rock burst is prone to occur.However,for the deep rock direct sampling test has many difficulties,therefore,it is necessary to simulate the dynamic mechanical properties of deep rock mass under the external load disturbance by using the similar material of rock burst in the laboratory.This paper selected the raw materials of Ganjiang River fine sand,cement and gypsum,mineral powder,iron powder and water for similar materials.Based on the orthogonal design test method,the similar material specimens were made with 3 factors of sand ratio,gypsum cement ratio and moisture content,and their mechanical properties were measured.According to the relationship between rock burst intensity and impact energy index and compressive tensile strength ratio,three kinds of rock burst similar material specimens are selected: ordinary material specimen,aluminum powder material specimen and iron powder material specimen.The prepared three kinds of rock burst similar materials were processed according to the requirements.Dynamic mechanical tests and one-dimensional static and dynamic combined loading tests were performed on the Hopkinson pressure bar device system.The stress-strain curves of specimens were obtained by processing experimental data.The dynamic failure stress-strain curves of three kinds of rock burst similar materials under the condition of four different impact pressures are analyzed:(1)The compressive strength of rock burst similar material with metal component is higher than that of common rock burst similar material specimen,and the compressive strength of similar material sample containing iron powder is higher than that of similar material sample containing aluminum powder?(2)The compressive strength of similar materials of rock burst increases with the increase of impact pressure.(3)The compressive strength of the similar material specimens with similar explosive loading under one-dimensional static and dynamic loading is higher than that under dynamic impact.(4)The rupture degree of the similar material sample of rock burst is related to the impact air pressure,the greater the impact pressure is,the more obvious the fracture degree is.Among them,the degree of fracture under one-dimensional dynamic and static loading is higher than that under dynamic impact. |
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