Research On The Controlling Technology Of Deferential Settlement In Express Highway Widening Projects

Express highway widening of our country now is in its early stage and no specific design or construction specification is available for it. Comparing to newly-build express highway, widening project is more difficult to construct and the technology is more complex. To mitigate the differential settlement is the key technology for express highway widening.With regard of the characteristics of express highway widening project, this paper conducted research on mitigating the differential settlement of widen roadbase, which mainly contained four parts as follows:1) Base on investigating express highway widening projects at home and abroad, the exciting problems, the mechanics and the key influential factors of differential settlement of widen roadbase have been analyzed.2) Finite element model was built to analyze the laws of differential settlement under different conditions such as widen methods, the height of robase and the geological conditions. Finite element model was also built to simulate the mechanical response of the pavement, base on which control criterion of differential settlement was put forward.3) Base on theoretical analysis and trial pavement section, some measures have been put forward to mitigate differential settlement of widen roadbase, including shoulder cutting, ground treatment, the application of geosynthetics, and so on.4 ) Considering the characteristics of widen roadbase, some technologies and measures to maintain the construction quality were put forward. Study was mainly conducted on the shoulder cutting and impact compacting of AN-XIN express highway widening project.