In order to research the surrounding rock deformation and failure mechanism of deep thick top coal roadway

taking Zhaolou coal mine in Juye mining area as engineering background

a large scale model test is carried out

the stress and displacement evolution laws of surrounding rock supported by pressure relief anchor cable box beam supporting programs are researched. And the results show: the vertical stress release is more intense in roof and floor of the roadway than that in the side wall

while the horizontal stress is the opposite; central of roadway roof is the main position of vertical stress release. By being compared with field test results

three main deformation and failure characters of the surrounding rock of deep thick top coal roadway are summarized: the deformation and failure of roof is more serious than that of side wall and floor; deformation and failure of roadway roof occurrs mainly in the coal below coal-rock interface; central of roadway roof is the key position of the deformation and failure. The corresponding mechanism is analyzed: the factors such as soft and broken features of roof coal

its poor self-supporting ability

vertical stress releasing more severe in roof and its central

poor force state of rectangle roadway

cause low radial stress of surrounding rock in roof

serve bulking deformation

bending deformation and roof separation

and worsen the roof force structure

finally

they lead to controlling trouble of roadway roof.