The Study Of Application Of Bulkhead Structure Of Battle And Sheet Pipe Pile Foundation Under High Reclamation

Considering the situation of the Yangshan Deep-water Port Project, and combined with the field prototype observation, we adopted both the 2-dimensional finite element numerical simulation method and the simplified 3-dimensional finite element method to study the calculation model of the bulkhead structure with inclined support pile and sheet pipe pile platform in this paper. Calculation model for general engineering design, technology requirements for design and correlative construction are also presented.The bulkhead structure with inclined support pile and sheet pipe pile platform is a special retaining structure created in the Yangshan Deep-water Port Project. The differential height between the soil of front and back of the structure is more than 20 meters. The soft soil layer there is thick and geological characteristic is bad. The speed of backfilling is fast while the period of the project construction is short. The function of this structure is not only retaining soil, but also protecting the jetty from the effect of deformation of the highly-backfilled clay. One of the key technical factors for the application of this structure is the calculation model.The 2-dimensional finite element numerical simulation method and the simplified 3-dimensional finite element method are both adopted to analyze this special structure. Through the sensitivity analysis of the main parameters of the two methods and compared with the result of prototype observed data, it follows that the consolidation of the backfilled clay by time, the non-linear of soil, the hydrological condition should be considered in the 2-dimensional finite element numerical model. Meanwhile, the physical and mechanical indexes of soil during its design, such as specific gravity and friction angle, should be chosen according to practical situation. The simplified 3-dimensional finite element method is an elastic method. In order to study its mechanical characteristic we should separate this structure from the soil, so m-value of soft foundation becomes a key factor. Specific gravity and friction angle are also important but no more than m-value. The physical and mechanical indexes of soil also should be chosen according to practical situation. Both of the two methods above can be adopted in structure design, the 2-dimensional finite element numerical simulation method is a little more complicated compared to the simplified 3-dimensional finite element method which is easier to master and is accord with the habit of engineering design.Through series of studies and practice, technology requirements for design and correlative construction of the bulkhead structure with inclined support pile and sheet pipe pile platform are presented, which is significant to the subsequent construction of the Yangshan Deep-water Port Project.