Study On The Critical Technology Of Classified Highway's Construction In Mined-out Region

When classified highway is constructed in mined-out region, the investment scale decides that it cannot adopt inner treatment of mined-out region. For classified highway constructed in mined-out region, in order to adapt to ground residual subsidence, it is necessary to analyze ground subsidence of mined-out region, optimize highway structures, and put forward construction strategies.The surface residual subsidence of mined-out region can be predicted by probability integration which includes the time parameter according to prevenient research by others. Through orthogonal experimental analysis of typical semi-rigid asphalt pavement structure with unbound graded aggregate transition layer, curvature k is the only significant index influencing pavement structure mechanical properties among all residual subsidence characteristic values of mined-out region.This paper proposes four typical bituminous pavement structures of classified highway in mined-out region: semi-rigid asphalt pavement structure with unbound graded aggregate transition layer, the traditional semi-rigid base asphalt pavement structure, LSAM base asphalt pavement structure and unbound graded aggregate base asphalt pavement structure. Take allowable tension stress of pavement structure layer as control index, this paper studies on the optimization of structure layer thickness, embankment reclamation height and processing depth. The research indicates embankment reclamation height and processing depth are more prominent for the ability of supporting surface residual subsidence, but changing structure layer thickness is less prominent. The traditional semi-rigid base asphalt pavement structure and unbound graded aggregate base asphalt pavement structure can adapt to residual subsidence better.Adopting classified highway accumulated standard axle loads between medium traffic and heavy traffic referring to actual specifications for design of highway asphalt pavement, computation gives the limits of ground redidual subsidence curve k allowed by allowable tension stress of pavement structure layers.Then, the thesis puts forward the classification indexes and limit values of surface residual subsidence which adapt to classified highway in mined-out region are set up. According to the classification indexes and limit values., the residual subsidence is divided into three grades: small, medium and large. It provides a theoretical basis for the construction strategies and pavements design of classified highway in mined-out region.