Study On Settlement Of High Xigeda Geogrid Embankment

Xigeda is a special rock distributed widely in Xichang and Panzhihua, Sichuan. Nearly one million cubic meters of Xigeda spoil are brought out in the build of Xichang-Panzhihua speedway. It will make considerable economic benefits if the spoil can be utilized effectively in the engineering. The geogrid is a high strength, small ductility, anti-aging geosynthetics. The geogrid placed in filling can reduce the uneven settlement. Currently, though many study results has been achieved in high-fill geogrid embankment, the corresponding study concerning Xigeda filling are relatively poor. The aim of this thesis is to study the stability of high Xigeda geogrid embankment with in situ test, centrifugal model test and numerical analysis, to server the design and construction.In the thesis, firstly the theory and method to analyse the settlement of reinforced embankment were introduced, and the corresponding achievements were summarized. To study the settlement of high Xigeda geogrid embankment, in site test including two groups with geogrid and the other two without geogrid was made, vertical and horizontal stress were measured with pressure sensors,. With the results, the influences of geogrid on the settlement of the embankment were analysed.Furthermore, finite element method was used to study the influences of the vertical spacing between layers of geogrid and the gradient slope of the embankment on the settlement of high Xigeda geogrid embankment. In the computation, Duncan-Chang model was employed for the filling soil..The results show that the distribution of the stress in geogrid embankment is improved by the geogrid observably, which will decrease the settlement of embankment. Moreover, the axial force of geogrid will increase, as the embankment slope become steeper. Further more, the settlement of embankment will decrease when vertical spacing between layers of geogrid becomes samller.