Seismic retrofit design and risk assessment of an irregular thermal power plant building

Summary This paper focuses on improvement of structural seismic performance under earthquakes of different intensities using a large mass ratio multiple tuned mass damper (LMTMD). A thermal power plant was taken as the example, and the plant was modeled using the finite element software ABAQUS. Coal buckets, which comprised 29.2% of the total mass of the structure, were used as the mass of the LMTMD. Thus, a large mass ratio was easily achieved without adding any extra mass. Incremental dynamic analysis was used to investigate the seismic fragility of the structures, and the seismic performances of the structure equipped with the LMTMD and the original structure were compared. The damping effectiveness and the control reliability of the LMTMD were evaluated. The fragility curves show that under rare earthquakes, the LMTMD reduced the probability of the moderate damage limit state by 43.9%, and under extremely rare earthquakes, the LMTMD exhibited good control robustness and reduced the probability of the severe damage limit state by 25.1%. Furthermore, the LMTMD could control the deformation pattern of the structure and effectively reduced concentrated damage, especially under high‐intensity ground motions; specifically, it reduced the average value of the interstory drift ratio by 1.2%–12% and reduced the standard deviation of the interstory drift ratio by 15%–62%. These results indicate that the LMTMD significantly improved the seismic performance of the structure with satisfactory reliability.

Section: Thermal Power Plant Structure With Coal Buckets As the Lmtmdmentioning

confidence: 99%

Section: Finite Element Model and Idamentioning

confidence: 99%

Seismic performances of a structure equipped with a large mass ratio multiple tuned mass damper

Kang

Peng

Pan

et al. 2020

“…The structural system for the thermal power plant for various capacities is similar in order to meet the needs of electricity production. [2,3,28] Numerical optimizations were first carried out using pattern search algorithm. [6] Seven objective functions are considered: base shear in The targeting of the procedure was first implemented for the scuttles of the seven cases, and 14 target modes per case were obtained.…”

Section: Parameter Calibration For the Thermal Power Plantmentioning

confidence: 99%

“…The model should keep main irregularities (plane and vertical). [3,28] b. The model should contain significant higher mode effects and torsional effects.…”

Section: Parameter Calibration For the Thermal Power Plantmentioning

confidence: 99%

Simplified design procedure for nonconventional multiple tuned mass damper and experimental validation

Dai

Meng

et al. 2020

Self Cite

SummaryA simplified design procedure, for nonconventional multiple tuned mass damper (TMD) (NC‐MTMD) system, was proposed. This system entails targeted tuning of each TMD by considering several mechanical factors (e.g., seismic excitation, TMD mass, and location). Subsequently, all TMDs are tuned to their corresponding modes by a group of semi‐empirical design formulae based on previous theoretical studies on MTMD systems, in the tuning phase. The procedure was then calibrated by numerical optimization results of an actual existing thermal power plant structure and validated in both comparative numerical study and a shaking table test. The experimental model was designed based on the thermal power plant structure configuration. Springs and eddy current dampers were adopted to model the resistance and energy dissipation of TMDs. A numerical comparative study was carried out between a traditional design method and the proposed design scheme. Six representative NC‐MTMD mass cases were investigated in the shaking table test to study the robustness of the method. The seismic mitigation efficiency was evaluated by comparison study on frequency, peak, and root mean square responses. The NC‐MTMD design was proved to be effective to help reduce seismic responses of the structure.

“…Coal‐fired thermal power plants (CFTPPs) as one of the most critical lifeline infrastructures play important roles not only in daily life but also in retrieval and revival after disasters 1 . However, they are vulnerable to earthquakes 2 . A typical CFTPP consists of four parts, that is, the support structure, the boiler, the hangers, and the stoppers (see Figure 1).…”

Section: Introductionmentioning

confidence: 99%

Shaking table test of the shock absorbing performance of a new cable‐damper stopper for coal‐fired thermal power plants

Jiang,

Duan,

Yue

et al. 2023

SummaryCoal‐fired thermal power plants play important roles in daily life but are vulnerable to earthquakes. This paper presents a novel cable‐damper stopper with linear damping and carries out a series of shaking table tests to evaluate its performance on a 1/25‐scaled coal‐fired thermal power plant. The stopper consists of a cable, a linear viscous damper and a steel block attached to the boiler. The seismic responses of the structure equipped with different sets of cable‐damper stoppers which are of different damping coefficients and diameters of cables were studied and evaluated, where three seismic ground motions with two intensities were selected as input motions. The obtained acceleration and displacement responses of the support structure and the boiler reveal that the stopper cable effectively restrains the relative displacement between the boiler and the support structure. Furthermore, it can be found that the damping affects the seismic protection performance of the stopper depending on the intensity of the boiler vibration. In the paper, the working mechanism of the stopper is also analyzed based on the test data. It turns out that the stopper is more effective when it works under severe earthquakes.