Control of seismic reactions of buildings and structures using friction movable joints (FMJ)

The paper discusses the possibility of increasing the plasticity coefficient of buildings and link by including in friction-movable joints on high-strength bolts in construction links. Such link connection is modeled by a dry friction damper or a dry friction damper with a decreasing friction force. The use of such joints makes it possible to increase significantly the area of static uncertainty loss in the monotonous loading diagram of the structure and, accordingly, the work of plastic deformation forces needed for the structure destruction. The paper considers two examples of using friction-movable joints. The first example is related to designing an onshore flyover sea platform. To provide the seismic platform stability proposed the authors to cut the platform longitudinally into onshore and offshore parts, which are connected by means of friction-movable joints. The second example relates to the seismic protection of railway bridges, in which the superstructure, in the place of location of fixed bearings, is connected to the bridge pier using a friction-movable joint. In this paper, the proposed connections are designed for the actions of design and maximum design earthquakes. Scenarios of damage accumulation in the structures under consideration during earthquakes are presented.