474
F. Scheaua
Depending on the constructive principle, insulation or energy dissipation systems
may be used at structures in order to reduce the efforts vertical transfer from the
ground foundation to the superstructure that must remain stable during an earthquake, or to consume an energy amount that is induced into the structure by seismic
movement.
Insulation systems positioned at the base of the structure (between the foundation and the superstructure) are considered as base insulation systems or dissipative
systems that are typically positioned between two distinct structural frames in order
to minimize relative displacements between them when a seismic motion occurs.
A composite insulation and dissipation system are presented for use in bridges or
viaducts structural isolation against the effects of seismic action.
It is a constructive solution that combines the isolation effect of the pendulum
systems that use the sliding movement positioned on a set of elastomeric elements.
The viscous fluid anchor system is additionally used for achieving superstructure
protection for dangerous displacements that would exceed the sliding bearings limit,
thereby endangering the superstructure stability [1, 2].
2 Constructive Details for the Composed Isolation Model
Assembly
Ensuring an improved behavior for a bridge structure during seismic movements is
a major requirement and must be taken into consideration the conditions in which
the efforts are transmitted vertically to the superstructure during the ground seismic
motion.
It is necessary to partially disconnect the superstructure from the foundation so
that the foundation is able to move with the ground while the superstructure remains
in a relative equilibrium position.
In order to achieve this, a base insulation system is installed between the two
structural elements (foundation and superstructure).
Due to the fact that the base insulation system introduces freedom of movement of
the superstructure; over many moving directions, there is the danger that at a certain
point in time when a high magnitude earthquake occurs, the superstructure tends to
overcome the constructive limit of the isolation system.
The solution for preventing this danger is represented by the use of the viscous fluid
dissipative system as anchor device ensuring the limiting of relative displacements
between the two structural elements of the bridge (foundation and superstructure)
and to complement the action of the pendulum insulation system at the structure base
[3].
The composed seismic protection system is made up of sliding pendulum system
supported on elastomeric material and viscous fluid dissipative systems used to limit
dangerous displacements on supports up to the breaking limit of the isolation system.
F. Scheaua
Depending on the constructive principle, insulation or energy dissipation systems
may be used at structures in order to reduce the efforts vertical transfer from the
ground foundation to the superstructure that must remain stable during an earthquake, or to consume an energy amount that is induced into the structure by seismic
movement.
Insulation systems positioned at the base of the structure (between the foundation and the superstructure) are considered as base insulation systems or dissipative
systems that are typically positioned between two distinct structural frames in order
to minimize relative displacements between them when a seismic motion occurs.
A composite insulation and dissipation system are presented for use in bridges or
viaducts structural isolation against the effects of seismic action.
It is a constructive solution that combines the isolation effect of the pendulum
systems that use the sliding movement positioned on a set of elastomeric elements.
The viscous fluid anchor system is additionally used for achieving superstructure
protection for dangerous displacements that would exceed the sliding bearings limit,
thereby endangering the superstructure stability [1, 2].
2 Constructive Details for the Composed Isolation Model
Assembly
Ensuring an improved behavior for a bridge structure during seismic movements is
a major requirement and must be taken into consideration the conditions in which
the efforts are transmitted vertically to the superstructure during the ground seismic
motion.
It is necessary to partially disconnect the superstructure from the foundation so
that the foundation is able to move with the ground while the superstructure remains
in a relative equilibrium position.
In order to achieve this, a base insulation system is installed between the two
structural elements (foundation and superstructure).
Due to the fact that the base insulation system introduces freedom of movement of
the superstructure; over many moving directions, there is the danger that at a certain
point in time when a high magnitude earthquake occurs, the superstructure tends to
overcome the constructive limit of the isolation system.
The solution for preventing this danger is represented by the use of the viscous fluid
dissipative system as anchor device ensuring the limiting of relative displacements
between the two structural elements of the bridge (foundation and superstructure)
and to complement the action of the pendulum insulation system at the structure base
[3].
The composed seismic protection system is made up of sliding pendulum system
supported on elastomeric material and viscous fluid dissipative systems used to limit
dangerous displacements on supports up to the breaking limit of the isolation system.