Seismic behavior of RC structures with absence of floor slab constraints and large mass turbine as a non-conventional TMD: a case study

Abstract

This paper presents a case study on the influence of absence of floor slab constraints and large mass turbine as a non-conventional tuned mass damper (TMD) on the seismic behavior of the structure and members. The investigated structural system is a reinforced concrete (RC) shear wall-frame power plant structure with large slab openings and a large mass turbine. In RC structures, the existence of floor slabs can usually provide strong constraints on beams so as to greatly increase their bearing capacity. However, due to some special functional demands, large area of slabs may have to be removed so that some floor beams will lose the constraints provided by slabs. In such cases, beams could be subjected to complex internal forces and develop unexpected failure modes under earthquake actions. Nonlinear time history analyses are conducted by using the self-developed program COMPONA-MARC Version 1.0. The numerical model employs fiber beam-column elements with distributed plasticity approach which can elaborately simulate the complex seismic behavior of structural members without slab constraints including the significant transverse vibration damage mechanism. For the seismic effectiveness of the turbine as a TMD with large mass ratio, the optimized parameters are discussed and verified by extensive numerical examples under a wide selection of ground acceleration time histories. The acceleration responses of the turbine are analyzed and found to satisfy the corresponding requirements. The dynamic interaction between the structure and turbine is evaluated and the effects of mass ratio and multiple supporting springs on the dynamic response of the turbine are investigated. It is found that the acceleration response of the turbine modeled with multiple supporting springs is evidently larger than that modeled with a single degree-of-freedom system, and the floor response spectrum decreases significantly with the increase of the mass ratio.

Seismic performance analysis of steel frame structures with separated three‐dimensional isolation

“…Numerical simulations and shaking table tests are conducted to study the isolation mechanism and seismic performance of the proposed separated 3D isolation scheme. In addition, as the isolation of the floor slabs weakens the constraint of the floor slabs to the beam and column members as in a traditional frame structure, 29 the influences of releasing floor slabs to the dynamic properties as well as the seismic behaviors of the structural members are investigated.…”

Seismic behavior of highly irregular structures with multiple passive energy dissipation system: Case study of a single‐column elevated station

“…Following his work, the effectiveness of frictional, viscoelastic, and tuned mass dampers in asymmetric systems was explored . Meanwhile, other researchers have emphasized on PED systems for vertically irregular structures, such as the multistory building structure with weak stories or uneven mass distribution caused by staggered floors, slabs with large openings, or heavy machineries. However, for more complex structures with both horizontal and vertical irregularities, such as the single‐column elevated station focused on herein, studies regarding effective PED systems and the assessment of their influences on structural seismic performance are rare.…”

Optimisation Design and Damping Effect Analysis of Large Mass Ratio Tuned Mass Dampers

“…e noncritical components in the structure, such as filled walls and floors, can also be used as the mass blocks to form a large mass ratio TMD [18,19]. In addition, the heavy equipment in an industrial plant can be constructed into a large mass ratio TMD in the form of suspension or isolation [20]. For example, in the typical coal-fired power plant, nonstructural coal buckets are used as the mass blocks of TMD or MTMD, which are called the coal bucket dampers.…”