The influence of pier height on the seismic isolation effectiveness of friction pendulum bearing for Double-Track railway bridges

Structures ◽  
2020 ◽  
Vol 28 ◽  
pp. 1870-1884
Author(s):  
Weikun He ◽  
Lizhong Jiang ◽  
Biao Wei ◽  
Zhenwei Wang
2018 ◽  
Vol 195 ◽  
pp. 02013
Author(s):  
Santi Nuraini ◽  
Asdam Tambusay ◽  
Priyo Suprobo

Advanced nonlinear analysis in light rail transit (LRT) structures has been undertaken to examine the influence of seismic isolation devices for reducing seismic demand. The study employed the use of two types of commercially available bearings, namely lead rubber bearing (LRB) and friction pendulum system (FPS). Six LRT structures, designed to be built in Surabaya, were modelled using computer-aided software SAP2000, where each of the three structures consisted of three types of LRB and FPS placed onto the pier cap to support the horizontal upper-structural member. Nonlinear static pushover and dynamic time history analysis with seven improved ground motion data was performed to gain improved insights on the behavioural response of LRT structures, allowing one to fully understand the supremacy of seismic isolations for protecting the structure against seismic actions. It is shown that both devices manage to isolate seismic forces, resulting in alleviation of excessive base shear occurring at the column. In addition, it is noticeable that the overall responses of LRB and FPS shows marginal discrepancies, suggesting both devices are interchangeable to be used for LRT-like structures.


Author(s):  
Ahmed Rageh ◽  
Daniel Linzell ◽  
Samantha Lopez ◽  
Saeed Eftekhar Azam

This chapter extends application of a framework proposed by the authors (73, 74) for automated damage detection using strain measurements to study feasibility of using sensors that can measure accelerations, tilts, and displacements. The study utilized three-dimensional (3D) finite element models of double track, riveted, steel truss span, and girder bridge span under routine train loads. The chapter also includes three instrumentation schemes for each bridge span (65) to investigate the applicability of the framework to other bridge systems and sensor networks. Connection damage was simulated by reducing rotational spring stiffness at member ends and various responses were extracted for each damage scenario. The methodology utilizes Supervised Machine Learning to automatically determine damage location (DL) and intensity (DI). Simulated experiments showed that DLs and DIs were detected accurately for both spans with various structural responses and using different instrumentation plans.


2014 ◽  
Vol 578-579 ◽  
pp. 1361-1365
Author(s):  
Lin Liu ◽  
Xuan Min Li ◽  
Wei Tian

Friction Pendulum Systems have been used as base isolation systems for both new construction and retrofit around the world. This paper presented its implementation in an office building located in Shanghai. To evaluate its impact on seismic performance of the retrofitted structure, models are needed to capture the intricate nonlinear behavior of both structural components and isolator elements. Nonlinear time history analysis of the building for the original and retrofitted cases was conducted to assess the efficiency of the isolation system at the high earthquake level. The numerical results indicate that the retrofitted structure experiences significantly less damage and less deformation due to the shake isolation and energy dissipation through the isolators.


Author(s):  
Thanh-Truc Nguyen ◽  
Nhan Dinh Dao

This study evaluates the accuracy of an equivalent linear model in predicting peak nonlinear time-history displacement of seismic isolation systems with single friction pendulum bearings. To perform this evaluation, dynamic response of numerical models of 120 isolation systems subjected to 390 strong earthquake ground motions, including motions with pulse and motions without pulse, was analyzed and statistically processed. The results show that the equivalent linear model can partly predict the peak displacement of its counterpart nonlinear model. However, the equivalent model can also underestimate or overestimate the peak displacement. On average sense, the equivalent linear model underestimates small peak displacement and overestimates large peak displacement. It is also observed that the relationship between linear and nonlinear peak displacements depends on ground motion types. Based on the analysis data, equations representing relationship between linear and nonlinear peak displacements at different reliable levels for different ground motion types were proposed. These equations can be used in practice.


2009 ◽  
Vol 36 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Woo Bum Kim ◽  
Kangmin Lee ◽  
Gil Hee Kim

An experimental and analytical study was performed to determine if the friction pendulum system (FPS) could be applied to the main control room (MCR) of a nuclear power plant as a seismic isolation device. A friction pendulum bearing was fabricated, and the dynamic performance of that bearing was evaluated. A partial model of the MCR with FPS was tested on a shaking table. The model consisted of a cabinet, an access floor, and four friction pendulum bearings. An artificial time history based on the MCR floor response spectrum was used as an earthquake input signal for the test. Analytical and experimental results were compared to verifiy their correlation and to enable the experimental study to cover a range of parametersnot previously studied in other similar experiments. Through these comparisons, it was affirmed that the proposed FPS seismic isolation system can be applied, with high reliability, to the MCR of a nuclear power plant.


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