Structural Types of Sea Embankment and Their Stability Analysis

In this paper based on investigation on the structural types of sea embankments in the southeast coastal area of China, as well as the related tidal stages, waves and strength of marine soils, the finite element method (FEM) calculations for seepage flow stability, including the overall stability against sliding and local stability of sloping surface under the action of tidal stage and waves are carried out. A comparison of the computational results of FEM for single circular slip, composite circular slip and geogrid reinforcement against sliding shows that for calculation of stability against sliding of marine soft soil foundation it is even more reasonable to use the composite circular slip. The stability of sloping type sea embankment against sliding is slightly better than that of the vertical face type; for the combination of three defences (wave, scour and seepage defences) the sea embankment structural type of a composite cross section with a platform should be a good one, but it still should be suitable to local conditions. For the local stability of riprap slope blocks and wall face loose masonry blocks, according to the analyses of wave-induced seepage flow fields, calculating formulas are given and they are verified by model test on block stability of breakwtwers.