Study On Resistance To Deformation Performance Of Graded Gravel Base Road In Subsidence Area

This paper takes the anti-deformation secondary road engineering of asphalt pavement with graded gravel base in Huainan mining area and the engineering geological conditions of Huainan area as the research background.According to the actual engineering of the deformation-resisting road in this area,the combined method of FLAC and PFC coupled numerical simulation and engineering application was used to study on resistance to deformation performance of graded gravel base asphalt pavement road in subsidence area.The anti-deformation laws of graded gravel base asphalt pavement with different mining was obtained,and the thicknesses of graded gravel base and lateral deformation joints against different mining deformations were summarized.The calculation results were applied to the actual project.The major accomplishments are as follows:(1)Asphalt pavement with graded gravel base is more resistance to mining deformation than cement stabilized gravel base asphalt pavement.Under the conditions of mining deformation,the tensile stress at the surface layer bottom of cement stabilized gravel base asphalt pavement surface layer is increased by18%-28.8% compared with graded gravel base asphalt pavement.(2)Under the premise of the influence of longitudinal negative curvature mining,the thickness of the asphalt surface layer is certain.For each additional10 cm of graded gravel base layer,the tensile stress at the surface layer bottom is reduced by about 10%.For each 1m increase in longitudinal length,the tensile stress at the bottom of the surface layer increases by about 10 KPa.(3)Under the premise of the influence of longitudinal negative curvature mining,the thickness of the asphalt surface layer is certain.With the increase of the thickness of the graded gravel base layer,the compressive strain at the top of the soil foundation decreases,and the decreasing trend will decrease with the increase of the thickness.There is no correlation between the longitudinal length and the compressive strain at the top of the soil foundation,and the compressive strain at the top of the soil foundation remains basically the same.(4)Under the premise of the influence of the road longitudinal negative curvature mining,The paper obtains the distance between the horizontal deformation joints of secondary roads in different grades of gravel base thickness and single coal seam thickness.