Base Structural Control In The Earthquake

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Abstract—Natural hazards such as earthquake occur often and damage the civil structure across the world. Collapse of building is due to the vibrations that occur during the earthquake. One such technique to establish effective structural control is base isolation system. It prevents the collapse of structure but not the contents present in it. To ensure the safety of building and its contents semi active control strategy has to be established. Semi active control of base isolated structure consists of friction pendulum bearing as passive isolators at the base with controllable semi active devices. Semi active actuators such as MR dampers are controlled by designing the PID controller due to its simplicity and effectiveness. Performance of the…show more content…
It is a disruptive disturbance that causes shaking of the surface of the earth due to underground movement along a fault plane or from volcanic activity. In-order to avoid the damages caused by the earthquake, civil structure is provided with base isolators. The concept of base isolation has been an active research area for about three decades which tend to resist the seismic excitation passaging from ground into the civil structure. Lead rubber bearings and friction pendulum bearings are the non-linear isolation devices mounted in between the super-structure and its foundation. Base isolation system reduces the seismic response in the super structure but with increased base displacements. In this work benchmark hysteretic base isolated building in Los Angeles, California is taken for the performance analysis of structure response during earthquake excitation. Sample earthquake data set that has been taken to analyze the base isolated structure is Newhall, Sylmar, El Centro, Rinaldi, Kobe, Jiji, Erzinkan. The base-isolated structure behaves as an elastic medium, so whenever the earthquake occur isolators displaces depending on the ground movement. Hence the seismic waves are arrested at isolation level itself. However, due to the elongation of isolators at the base alters the position of contents present in the structure. In fixed base, the structure would…show more content…
Experimental study of sliding baseisolated buildings [7] [8] with MR Dampers in near-fault earthquakes was conducted in which use of supplemental nonlinear passive dampers in the isolation system reduces the base displacements, however, this increases the interstorey drifts and accelerations in the superstructure.
A 3D benchmark model of an eight-storey base isolated building with lateral-torsional behavior has been developed as per the directions of ASCE Committee [3]. It is similar to the existing building in Los Angeles, California. The building has a rigid steel-framed superstructure and consists of eightstorey.
The plan is L-shaped that is shown in Fig 2 (a) which is asymmetry in both directions and has dimensions of 82.4m length and 54.3m breadth. The superstructure is assumed to remain in the linear-elastic regime, while the nonlinearities in the isolation system provide for the energy dissipation or absorption. The asymmetry in the plan causes the structure responses to contain significant torsional components in addition to the lateral components.
A finite element model of the super-structure was constructed using the commercial finite element

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