Ecological Study on Sound Field Characteristics and Sound Propagation Law in Environment of Fully Mechanized Mining Face based on Finite Element Method

Based on the finite element method (FEM), the microelement mesh model of sound energy density and sound pressure level in the environment of fully mechanized mining face is established, and the ecological simulation of the noise field characteristics in the long space of the fully mechanized roadway is carried out by using COMSOL Multiphysics. The influence of the distance of the receiving point, the shape of the section and the area of the section on the sound field of the roadway is analyzed on the basis of soundscape ecology. The results show that: (1) In the whole tunnel space, when the receiving point is close to the sound source, the attenuation is very fast and close to linear attenuation. When the receiving point is located at a certain distance from the outlet of the roadway, the sound energy basically remains unchanged in the environment. When the receiving point is close to the exit position of the end face, the attenuation of small amplitude appears again; (2) If the cross-sectional geophysical area of the fully mechanized mining work is constant, when the cross-sectional shape is trapezoidal or rectangular. The attenuation trend of acoustic energy along the distance is basically the same. And the change rate of the cross-sectional shape to the sound pressure level is not much different, but when the cross-sectional shape is trapezoidal, the noise attenuation is faster; (3) The section area of fully mechanized coal mining has great ecological influence on the sound pressure level, and the larger the section area, the faster the decline.