The stability of seafloor is one of the geotectmical problems that need to be solved. A practical model for analysis is proposed in this paper. The model is based on the concept of Discontinuous Deformation Analysis (DDA) by Shi (1988). DDA is well known for its capability in analyzing large strain problems for discontinuous problems. However, DDA does not incorporate pore pressures and drained conditions between blocks. In this study, modifications were tried to improve this deficiency. Since DDA gives the progressive displacements and deformations of blocks, failure criteria can be observed. Thus, this paper demonstrates the applicability of DDA to analyze the stability of seafloor.
Exploration of the oceans has always been the attention of mankind. In the past few decades, there have been an increasing intensity of exploration as reclamation of land is conducted in the coastal area or in a deep-sea area. In the 1990, the Ministry of Economical Affairs in Taiwan declared a requirement of land reclamation including approximately 10,000 hectares in the West Taiwan Nearshore. The reclamation of land involves man)" geotechnical problems that must be solved. In the recent years, hydraulic sand fills method has been one of the most important reclamation method. In general, using this reclamation method, the filled soil pumped by" machines would induce changes in the seafloor. Thus, the stability of seafloor is an important research topic. Henkel (1970) was the first to take wave forces into account for submarine rotational slips. The effects of the passage of a sinusoidal transient wave pressure on the underwater slope were considered. Henkel (1970) demonstrated that the pressure changes on the seafloor associated with the passage of a wave are able to cause shear failure in soft sediments in water depth up to about 120m.
