Study on stress characteristics of high-porosity coal gangue subgrade during filling process

By analyzing geological conditions of a coal gangue filling roadbed, stress characteristics and settlement changes during the filling process of the coal gangue roadbed are simulated. The following conclusions are drawn: (1) As height of the coal gangue filling increases, the stress and settlement of each part will also increase. (2) During the filling process, the vertical stress acts as the first principal stress, and the stress and strain at the centerline of the roadbed are 10 times that of the roadbed. (3) The final stable value of uneven settlement of the coal gangue roadbed is 18.85mm. (4) The monitoring results indicate that the settlement of the coal gangue roadbed is stable, and the settlement amount is small ensuring safety of the roadbed.