Dynamic behavior of a softer layer overlying hard soil / bedrock and vibration reduction

摘要

For new buildings constructed on layered soil conditions and located near heavy traffic or industrial areas, ground vibrations are more and more an issue of concern. Considering different soil conditions the two-layer soil system consisting of a softer layer overlying a stronger one or hard soil is often a realistic approximation for geotechnical engineering design. A numerical investigation on the dynamics of this two-layer soil system is carried out using finite element (FE) method. Transient analysis is applied employing implicit time integration and incorporating an absorbing boundary formulation to simulate radiation damping at infinity. The dynamic stiffness of a single footing resting on this two-layer soil system is also investigated by Echo Models, which represent an alternative to the rigorous approaches. Based on the dynamic of the foundation - two layer soil system interactions the affectivity of the design of a mitigation measure for environment vibration is presented. Numerical examples highlight the efficiency of the method in reducing ground vibrations.