Explore the vast range of titles available.

The dynamic shear modulus G of soil was determined using a dynamic triaxial test system（DTTS） together with a fitting method.First,a novel linear relationship between G and damping ratio λ was proposed,which was used to select the appropriate G.Then,a hyperbolic model was constructed using the optimized parameters a and b representing the intercept and slope,respectively,from the linear regression of 1/G and dynamic shear strain γd.Finally,the differences between the tested and predicted results for G were analyzed for different soil types.The experimental results show that this linear relationship can overcome the shortcomings of the nonlinear relationship found in the large deformation stage and can predict λ in the hysteresis loop that is not closed case.In addition to Baoji loess,G was slightly larger（10%） than the experimental curve in the elasto-plastic stage;however,the experimental results show that the attenuation curve of G for Baoji loess is greater than the calculated value in the elasto-plastic stage.The test and analysis results will improve the knowledge of the dynamic properties of soils and also provide reliable values of G for further evaluation of seismic safety at engineering sites.

Consideration of structure-foundation-soil dynamic interaction is a basic requirement in the evaluation of the seismic safety of nuclear power facilities. An efficient and accurate dynamic interaction numerical model in the time domain has become an important topic of current research. In this study, the scaled boundary finite element method （SBFEM） is improved for use as an effective numerical approach with good application prospects. This method has several advantages, including dimensionality reduction, accuracy of the radial analytical solution, and unlike other boundary element methods, it does not require a fundamental solution. This study focuses on establishing a high performance scaled boundary finite element interaction analysis model in the time domain based on the acceleration unit-impulse response matrix, in which several new solution techniques, such as a dimensionless method to solve the interaction force, are applied to improve the numerical stability of the actual soil parameters and reduce the amount of calculation. Finally, the feasibility of the time domain methods are illustrated by the response of the nuclear power structure and the accuracy of the algorithms are dynamically verified by comparison with the refinement of a large-scale viscoelastic soil model.