Composed Isolation System Concept for Vibration Effects Mitigation …
481
The effective damping for a specific displacement (u) on the support is described
by the relation [5]:
A e f =
E dis
4π E c
=
2μR
π (μR + u)
(14)
Based on the corresponding values for the two analyzed cases, the graphical
representations of the effective damping obtained by the movement on the supports
are realized, as shown in Fig. 6 [5].
The maximum effective damping values are recorded for the higher radius of
curvature values of the rolling concave surface, but also for the high frictional
coefficient values between the two surfaces in contact.
5 Conclusion
A model of an insulating system that also has energy dissipative properties is
presented in this paper which can be mounted on the bridge or viaduct construction
structures.
It is a composed system having in composition rolling pendulum bearings utilizing
the rolling motion of a spherical piece on a concave surface whose insulating action
is combined with the energy dissipation action of a hydraulic system operating with
viscous fluid.
By mounting at the insulated structure, the composite system disconnects the
structural elements represented by the foundation and the superstructure, allowing
the foundation to move along with the terrain required by the seismic shock wave,
while the superstructure tends to maintain the inertial equilibrium.
Due to an earthquake, displacements on the supports occur, which can be both
translations in different directions, as well as rotations.
The concave shape of the sliding surface ensures the displacements and also the
return to the initial position according to superstructure own weight.
This composite system model can be used to isolate bridge structures, viaducts,
as well as not very high buildings.
In the event of a severe earthquake, the structure can reach the upper boundary
limit of the movement on the supports and there is the danger of support destruction.
To avoid this undesirable situation, the configuration of the isolator system has
been modified by adding viscous fluid dissipative systems in order to limit dangerous
displacements and providing anchoring points that add additional damping to the
insulator assembly.
481
The effective damping for a specific displacement (u) on the support is described
by the relation [5]:
A e f =
E dis
4π E c
=
2μR
π (μR + u)
(14)
Based on the corresponding values for the two analyzed cases, the graphical
representations of the effective damping obtained by the movement on the supports
are realized, as shown in Fig. 6 [5].
The maximum effective damping values are recorded for the higher radius of
curvature values of the rolling concave surface, but also for the high frictional
coefficient values between the two surfaces in contact.
5 Conclusion
A model of an insulating system that also has energy dissipative properties is
presented in this paper which can be mounted on the bridge or viaduct construction
structures.
It is a composed system having in composition rolling pendulum bearings utilizing
the rolling motion of a spherical piece on a concave surface whose insulating action
is combined with the energy dissipation action of a hydraulic system operating with
viscous fluid.
By mounting at the insulated structure, the composite system disconnects the
structural elements represented by the foundation and the superstructure, allowing
the foundation to move along with the terrain required by the seismic shock wave,
while the superstructure tends to maintain the inertial equilibrium.
Due to an earthquake, displacements on the supports occur, which can be both
translations in different directions, as well as rotations.
The concave shape of the sliding surface ensures the displacements and also the
return to the initial position according to superstructure own weight.
This composite system model can be used to isolate bridge structures, viaducts,
as well as not very high buildings.
In the event of a severe earthquake, the structure can reach the upper boundary
limit of the movement on the supports and there is the danger of support destruction.
To avoid this undesirable situation, the configuration of the isolator system has
been modified by adding viscous fluid dissipative systems in order to limit dangerous
displacements and providing anchoring points that add additional damping to the
insulator assembly.