A new artificial boundary condition for time domain analysis of a structure-unlimited-foundation system was proposed.The boundary condition was based on the damping-solvent extraction method.The principle of the damping-solvent extraction method was described.An artificial boundary condition was then established by setting two spring-damper systems and one artificial damping limited region.A test example was developed to verify that the proposed boundary condition and model had high precision.Compared with the damping-solvent extraction method,this boundary condition is easier to be applied to finite element method(FEM)-based numerical calculations.
The dynamic responses of the arch dam including dam-foundation-storage capacity of water system,using two different earthquake input models,i.e.viscous-spring artificial boundary(AB)condition and massless foundation(MF),were studied and analyzed for the 269 m high Baihetan arch dam under construction in China.By using different input models,the stress and opening of contraction joints(OCJs)of arch dam under strong shock were taken into consideration.The results show that the earthquake input models have slight influence on the responses including earthquake stresses and openings of contraction joints in different extents.
A new finite element method （FEM） of B-spline wavelet on the interval （BSWI） is proposed. Through analyzing the scaling functions of BSWI in one dimension, the basic formula for 2D FEM of BSWI is deduced. The 2D FEM of 7 nodes and 10 nodes are constructed based on the basic formula. Using these proposed elements, the multiscale numerical model for foundation subjected to harmonic periodic load, the foundation model excited by external and internal dynamic load are studied. The results show the pro- posed finite elements have higher precision than the tradi- tional elements with 4 nodes. The proposed finite elements can describe the propagation of stress waves well whenever the foundation model excited by extemal or intemal dynamic load. The proposed finite elements can be also used to con- nect the multi-scale elements. And the proposed finite elements also have high precision to make multi-scale analysis for structure.
