Self-Tuning Fuzzy Control for Seismic Protection of Smart Base-Isolated Buildings Subjected to Pulse-Type Near-Fault Earthquakes

A typical reinforced concrete rib arch bridge was chosen to investigate its nonlinear response to near-fault ground motions recorded in 2008 Wenchuan earthquake. Results showed that significant seismic damage may occur, maximum demands were higher for near-fault records having forward directive than far-fault motions, and the rotational capacity of rib plastic hinge is not enough for the large compression force of arch rib. While backward-directivity motions, typically do not exhibit pulse-type motions, only have medium seismic damage to the arch bridge.

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Fuzzy Control for Seismic Protection of Semiactive Base-Isolated Structures Subjected to Near-Fault Earthquakes

Mathematical Problems in Engineering ◽

10.1155/2015/675698 ◽

2015 ◽

Vol 2015 ◽

pp. 1-17 ◽

Cited By ~ 3

Author(s):

Dahai Zhao ◽

Yongxing Li

Keyword(s):

Fuzzy Logic ◽

Fuzzy Logic Controller ◽

Fuzzy Controller ◽

Seismic Protection ◽

Friction Damper ◽

Design Spectrum ◽

Near Fault ◽

Isolated Structures ◽

Near Fault Earthquakes ◽

Elastic Design

This paper proposes a new fuzzy logic controller, which is designed for seismic protection of base-isolated structures utilizing piezoelectric friction damper against near-fault earthquakes for different ground sites. According to the elastic design spectrum that Eurocode 8 recommends, one 5% damped elastic design spectrum for Chi-Chi earthquake is proposed to generate artificial earthquakes of different ground sites. The proposed controller employs a hierarchic fuzzy control algorithm, in which a supervisory fuzzy controller governs a sublevel fuzzy controller by altering its input normalization factors according to current level of ground motion. In order to simultaneously reduce the base displacement and superstructure responses of the base-isolated structure during seismic excitations, genetic algorithm is employed to optimize the supervisory fuzzy controller and the preload of piezoelectric friction damper. The efficiency of the proposed controller is also compared with passive controller and a linear quadratic Gauss optimal controller. Numerical results show that the proposed fuzzy logic controller has favorable performance in mitigating the responses of the base-isolated structure.

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Semi-active fuzzy control for seismic response reduction of building frames using variable orifice dampers subjected to near-fault earthquakes

Journal of Vibration and Control ◽

10.1177/1077546312449179 ◽

2012 ◽

Vol 19 (13) ◽

pp. 1980-1998 ◽

Cited By ~ 18

Author(s):

Hossein Ghaffarzadeh ◽

Ebrahim Alizadeh Dehrod ◽

Nima Talebian

Keyword(s):

Fuzzy Control ◽

Seismic Response ◽

Building Frames ◽

Near Fault ◽

Near Fault Earthquakes

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A simplified iterative approach for testing the pulse derailment of light rail vehicles across a viaduct to near-fault earthquake scenarios

Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit ◽

10.1177/0954409720987410 ◽

2021 ◽

pp. 095440972098741

Author(s):

Ling-Kun Chen ◽

Peng Liu ◽

Li-Ming Zhu ◽

Jing-Bo Ding ◽

Yu-Lin Feng ◽

...

Keyword(s):

Ground Motions ◽

Simulation Software ◽

Light Rail ◽

Rail Transit ◽

Light Rail Transit ◽

Seismic Responses ◽

Near Fault ◽

Rail Vehicle ◽

Pulse Type ◽

The Impact

Near-fault (NF) earthquakes cause severe bridge damage, particularly urban bridges subjected to light rail transit (LRT), which could affect the safety of the light rail transit vehicle (“light rail vehicle” or “LRV” for short). Now when a variety of studies on the fault fracture effect on the working protection of LRVs are available for the study of cars subjected to far-reaching soil motion (FFGMs), further examination is appropriate. For the first time, this paper introduced the LRV derailment mechanism caused by pulse-type near-fault ground motions (NFGMs), suggesting the concept of pulse derailment. The effects of near-fault ground motions (NFGMs) are included in an available numerical process developed for the LRV analysis of the VBI system. A simplified iterative algorithm is proposed to assess the stability and nonlinear seismic response of an LRV-reinforced concrete (RC) viaduct (LRVBRCV) system to a long-period NFGMs using the dynamic substructure method (DSM). Furthermore, a computer simulation software was developed to compute the nonlinear seismic responses of the VBI system to pulse-type NFGMs, non-pulse-type NFGMs, and FFGMs named Dynamic Interaction Analysis for Light-Rail-Vehicle Bridge System (DIALRVBS). The nonlinear bridge seismic reaction determines the impact of pulses on lateral peak earth acceleration (Ap) and lateral peak land (Vp) ratios. The analysis results quantify the effects of pulse-type NFGMs seismic responses on the LRV operations' safety. In contrast with the pulse-type non-pulse NFGMs and FFGMs, this article's research shows that pulse-type NFGM derail trains primarily via the transverse velocity pulse effect. Hence, this study's results and the proposed method can improve the LRT bridges' seismic designs.

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Influence of Elastomeric Bearings in Tension on the Seismic Performance of Base-Isolated r.c. Buildings

Applied Sciences ◽

10.3390/app11010082 ◽

2020 ◽

Vol 11 (1) ◽

pp. 82

Author(s):

Fabio Mazza ◽

Mirko Mazza

Keyword(s):

Base Isolation ◽

Nonlinear Models ◽

Vertical Component ◽

Computer Code ◽

Nonlinear Phenomena ◽

Isolation System ◽

Elastomeric Bearings ◽

Near Fault ◽

Base Isolation System ◽

Near Fault Earthquakes

Elastomeric bearings are commonly used in base-isolation systems to protect the structures from earthquake damages. Their design is usually developed by using nonlinear models where only the effects of shear and compressive loads are considered, but uncertainties still remain about consequences of the tensile loads produced by severe earthquakes like the near-fault ones. The present work aims to highlight the relapses of tension on the response of bearings and superstructure. To this end, three-, seven- and ten-storey r.c. framed buildings are designed in line with the current Italian seismic code, with a base-isolation system constituted of High-Damping-Rubber Bearings (HDRBs) designed for three values of the ratio between the vertical and horizontal stiffnesses. Experimental and analytical results available in literature are used to propose a unified nonlinear model of the HDRBs, including cavitation and post-cavitation of the elastomer. Nonlinear incremental dynamic analyses of the test structures are carried out using a homemade computer code, where other models of HDRBs considering only some nonlinear phenomena are implemented. Near-fault earthquakes with comparable horizontal and vertical components, prevailing horizontal component and prevailing vertical component are considered as seismic input. Numerical results highlight that a precautionary estimation of response parameters of the HDRBs is attained referring to the proposed model, while its effects on the nonlinear response of the superstructure are less conservative.

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Seismic Response of RC Frames with a Soft First Story Retrofitted with Hysteretic Dampers under Near-Fault Earthquakes

Applied Sciences ◽

10.3390/app11031290 ◽

2021 ◽

Vol 11 (3) ◽

pp. 1290

Author(s):

Santiago Mota-Páez ◽

David Escolano-Margarit ◽

Amadeo Benavent-Climent

Keyword(s):

Cost Effective ◽

Far Field ◽

Soft Story ◽

Near Fault ◽

Rc Frames ◽

Story Drift ◽

Number Of Cycles ◽

Rc Frame Structures ◽

Near Fault Earthquakes ◽

Hysteretic Dampers

Reinforced concrete (RC) frame structures with open first stories and masonry infill walls at the upper stories are very common in seismic areas. Under strong earthquakes, most of the energy dissipation demand imposed by the earthquake concentrates in the first story, and this eventually leads the building to collapse. A very efficient and cost-effective solution for the seismic upgrading of this type of structure consists of installing hysteretic dampers in the first story. This paper investigates the response of RC soft-story frames retrofitted with hysteretic dampers subjected to near-fault ground motions in terms of maximum displacements and lateral seismic forces and compares them with those obtained by far-field earthquakes. It is found that for similar levels of total seismic input energy, the maximum displacements in the first story caused by near-fault earthquakes are about 1.3 times larger than those under far-field earthquakes, while the maximum inter-story drift in the upper stories and the distribution and values of the lateral forces are scarcely affected. It is concluded that the maximum displacements can be easily predicted from the energy balance of the structure by using appropriate values for the parameter that reflects the influence of the impulsivity of the ground motion: the so-called equivalent number of cycles.

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