3D Nonlinear Analysis Of Stress And Deformation For CFRD By Using ABAQUS-based Redevelopment

On the progress with the great scale of constructions for water resources and hydropower stations in our country, Concrete Face Rockfill Dams (CFRD) have become increasingly popular types which is the most competitive and preferable for recent years. It is usually needed to carry out deformation-stress analysis and to evaluate performance for a CFRD subjected to some three-dimensional complex loads during its service period in order to optimize massed zones, design waterproof systems, control construction phases and reduce project investment.Therefore, Based on User Subroutines in ABAQUS which is an advanced nonlinear FE analysis implement for general purpose, an enhancement feature, which is suitable to accomplish deformation and stress analysis by using Duncan-Chang constitutive model for CFRD, is implemented successfully and was applied for a CFRD project in China.The major contents in this thesis are as follows:1) The simulation methods were discussed for CFRD while constructing phase and storing water phase, and some new views were conducted for discontinuous deformation at the two sides of the slab joints and the contact between the concrete slab and the cushion.2) Duncan-Chang constitutive model is used to analyse rockfill materials and new failure criterion is given to them in three-dimensional spaces. Some new numerical techniques of iteration are also suggested for CFRD analysis.3) Choosing ABAQUS software as the high level development platform at first time, the redevelopment procedures to add Duncan-Chang constitutive model were described and were compiled to codes. Some numerical verifications were then examined strictly. According to the data of typical conventional triaxial compression tests and the theory results of Duncan-Chang constitutive model, the verifications show that the redevelopment is successful and the program codes have some obvious advantages with high efficiency, high precision, and are easy to be maintained.4) A case study of CFRD's deformation and stress analysis used the redevelopment program was introduced and showed some powerful capacities to solve three-dimensional complex engineering problems.All the schemes proposed in this thesis have strong utility to nonlinear analysis ofdeformation and stress for CFRD and are cable of reference to numerical simulation research for geoengineering, hydropower structures and other engineering fields.