Additional Stress Analysis And Reinforcement Measures Of Super-Wide Embankment On Soft Soil

With the development of high-speed railway and railway line for passenger traffic,it requires more advanced technique on settlement deformation of subgrade.Soft clay foundation is widely distributed along the coastal region of our country,in many projects which are under construction such as Yong-Tai-Wen,Wenzhou to Fuzhou,Fuzhou to Xiamen,engineers apply pre-stressed concrete cube pile,the CFG pile(concrete-flash-gravel pile) etc,to the foundation treatment.The use of these composite foundations proved to be good.However,it also has limitation,for example,high costs.Multi-element composite foundation is a new style which contains any pile style associating with drainage consolidation,rigid-flexible pile, long-short pile and so on.In the composite foundation,the use of reinforce can be the same longth,or the long-short pile style.And long piles and the short ones can be made with the same material or the different ones.We called it multi-element composite foundation when the long-short piles were made with the different materials.It uses long pile and drainage consolidation to control the settlement and the flexible-short pile to improve the bearing capacity of foundations.It is not widely used in the Ministry of Railways as more as in high-rise buildings and highway engineering because of the low cost,and we run short of information of its reinforcement mechanism, therefore,it was not used abroadly in high-speed railway system.The station is 3 kilometers long,and the height of fill is 7 meters,the soft soil area needed to be treated is about 2million m~2,and most of the structures are built in bad stratas.According to this project,the degree of consolidation was calculated,and the results proved that it can matisfy the requirement of settlement and the construction period if we use the plastic drain slab.So,the CFG pile associated with plastic drain slab,pre-stressed concrete cube pile associated with with plastic drain slab,CFG pile and pre-stressed concrete cube pile with plastic drain slab can be used to treat the deep soft soil foundation.And the bearing capacity of foundation and the settlement of them was calculated.At the end of the paper,the additional stress of the super-wide embankment was done with the software called "ansys".From the results,we can know that the settlement was greatly effeted by the width of embankment when the length is shorter than 80m,but the influence is not obviouse when it is longer than 80m.The maxisum settlemnt is also different as the width changes.The settlement curve is like a "parabola"when the roadbed is narrow because the settlement in the middle is the biggest.As the width grows,the bottom of the basin becomes square-built and smooth,it is a transition from narrow to open.The settlement curve is like an asymmetric saddle shape.