(1. College of Hydraulic Science and Engineering，Yangzhou University，Yangzhou，Jiangsu 225009，China；2. Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources，Yangtze River Scientific Research Institute，Wuhan，Hubei 430010，China；3. DDA Center of Yangtze River Scientific Research Institute，Wuhan，Hubei 430010，China)
Abstract：Applying three-dimensional high order discontinuous deformation analysis(DDA) with the volume- oriented advantage to structure static analysis gets rid of the limit of compatible mesh，which helps to simplify the preprocessing. Furthermore，by introducing high-order displacement mode，higher precision can be gained when the three-dimensional structure is simply divided into only one or few blocks. Based on above idea，the concepts of connecting face and connecting point pair is defined；and the deformation compatibility conditions of high-order DDA block in continuous structure computation are presented；then the principal formulas of three- dimensional high-order DDA are deduced，including elastic sub-matrix，initial stress load matrix，point load matrix，volume load matrix，fixed point matrix and the connecting matrix of adjacent blocks. The whole balance equations are established at last. Above thought is realized by program. Comparative analysis of some typical samples is applied between the method，analytic solution and finite element results. It shows the feasibility and advantage of DDA method in the static computation of continuous structure.
