Researches On Dynamic Interaction Of Machine Foundations

As the enhancement of industrialization, dynamic machine foundations are more and more extensively applied to industry, transportation, etc. The running of machine often causes vibration of soil, which has dynamic action to the running of machine in reverse, as a result, machine foundation and its soil constitute a vibration system. That also causes vibration of soil, or even the building nearby, which may influence the safety of building or normal work of the worker. Sometimes, because of the require of layout, or the needs of modification and enlargement of the project, the distances between machines is always too close, the adjacent foundations have dynamic actions to each other when they are working, and if the foundations are not correctly designed, it may cause too large vibration. Therefore, we must limit the vibration displacement (or vibration velocity, vibration acceleration) that may be caused to a range to ensure worker's health and the safety of building, and also ensure that the machine can work normally.Currently, most of the calculation methods for dynamic machine foundation design can only design single foundation, however, as for multiple foundations which are close to each other, they can't consider the interaction between them. This article carries out discussion to this problem, so as to offer academic and technical support for the design.In this article, the methods (such as the theory of mass-dashpot-spring, the theory of elastic half– space and numerical simulation method) for the design of dynamic foundation are discussed, by comparison and analysis, the numerical simulation method is selected as a tool in the study for its simplicity and convenience. Second, with finite element method (FEM), a appropriate FEM model of dynamic foundation is established.At last, according to the FEM model established, follow issues are studied:(1) Ground stiffness and foundation thickness'influences on the vibration of single foundation. (2) Combining plane's influence on the vibration to combined foundation and vibration rule of two foundations with a constant phase difference. (3) the minimum distance between two foundations and vibration rule of two foundations with a constant phase difference.Through the study on above issues, some factors'(such as ground stiffness, thickness of foundation, combining plane of combined foundation, the distance of two foundations, and phase difference of two machines, etc.) influence on the vibration of dynamic foundation in design are obtained, which can beconsulted in dynamic foundation design, or used as data in the study on dynamic foundation.