The Settlement Predition Of Subgrade Above Goaf And Research Of Reasonable Tranisitional Paement Structure

As an important part of road transportation, highway plays an irreplaceable role in the national economy rapid development. In the mining industry developed regions, More and more road inevitably need to built across mined-out area, because of its own gravity and traffic load, rock mass overlying the goaf may generate horizontal movement, inclination, subsidence,and other deformation, which may cause cracking of the road surface, roadbed subsidence, or even a large area of subsidence and other damage. This would seriously threaten traffic safety.In order to ensure traffic safety in the mined-out area and reduce economic losses, must evaluate the stability of goaf before the construction of roads in mined-out area. Goaf section of 323 Henan Road is taken as the engineering background in this paper, consider the activity of goaf foundation, the location of goaf distribution and time effect, use adopt improved creep constitutive model to calculate and analyze the law of subgrade settlement.Determine the critical security zone of goaf, then establish the subgrade settlement prediction model within the scope of the goaf. Which provide reference for the design and construction of the actual project. The main conclusions are as follows:(1) Under different mining depth analysis of the maximum settlement and differential settlement of subgrade above the mined-out area, it is concluded that the largest settlement changing with the depth of the mined-out area; Analysis of the mining depth is obtained at constant embankment settlement with the mined-out area away from the settlement of highway horizontal distance changes regularly.(2) Choose three index curve and roadbed subsidence prediction model combining the Peck formula, compared with the results of numerical simulation of fixing the forecasting model, a revised forecast model to predict the subgrade settlement data and project of highway subgrade has better fit the measured deformation.(3) Through the comparison and analysis of the four different pavement in goaf geotechnical broken and the lower the loess under the action of uneven settlement, consolidation settlement deformation of flexible pavement structure are more comfortable with this, recommend the gravel road pavement structure as goaf transition at the grass-roots level.