Research On The Design Approach Of Widening Of Highway On Soft Ground

The right design approach of widening of highway on soft ground is a difficult problem in the construction of highway that must be solved urgently now. Widening of highway on soft ground may meet with the issues such as the different settlement of the old and new embankments, the juncture of old and new abutment. The finite element technique using a Mohr-Coulomb elastic-plastic soil behavior model are applied to the analysis of interaction mechanism between the old and new embankments in the widening of highway embankments on soft foundation soils.Use some good design approach to solve engineering problem of widening of embankment, bridge and culvert.First, based on the review of widening of highway, a comprehensive introduction is given to the problems of widening highway on the soft foundation.Second,A numerical model based on plane strain finite element method (FEM) is used and its theoretical hypotheses are Biot consolidation theory and Mohr-Coulomb elastic-plastic soil model. During building-running-widening-running, The influences on embankment and groundwork in the joint owing to widening are analyzed, including settlement, horizontal displacement and stress. Conclusions are gained that after widening, the settlement of two sides of the old road pavement is contrary, cross slope of old road is different, horizontal displacement of the old road pavement is minishes, the area of maxium settlement, maxium lateral displace and disease of old road is different as before widening. And the area and scale of maxium settlement, maxium lateral displace and the maxium shear stress of widening road is different as new highway. Other, the thesis studies the different settlement of new and old road after widening, too.Through analyzing and discussing several typical soft ground treatment, the method of ground treatment in widening road is brought forward, and it is applied to the project. To all kinds of widening roads, a characteristic of design approach is summed up,and the standard of settlement about widening road is studied.Finally,the characteristic of widening bridge is studied, and the cause of settlement of the abutment is analysed. And the design approach of widening bridge and culvert is studied and summarized.