Effect of inerter for seismic mitigation comparing with base isolation

2019 ◽  
Vol 26 (10) ◽  
Author(s):  
Luyu Li ◽  
Qigang Liang
Keyword(s):  
Base Isolation ◽  
Seismic Mitigation

Bio-Inspired Passive Optimized Base-Isolation System for Seismic Mitigation of Building Structures

2016 ◽  
Vol 142 (1) ◽  
pp. 04015061 ◽  
Author(s):  
Xi Chen ◽  
Henry T. Y. Yang ◽  
Jiazeng Shan ◽  
Paul K. Hansma ◽  
Weixing Shi
Keyword(s):  
Base Isolation ◽  
Building Structures ◽  
Isolation System ◽  
Base Isolation System ◽  
Seismic Mitigation

Applications of Multiple Trench Friction Pendulum System to Seismic Mitigation of Structures

2008 ◽  
Author(s):  
C. S. Tsai ◽  
Jeng-Wen Lin ◽  
Yung-Chang Lin ◽  
Chia-Chi Chen
Keyword(s):  
Base Isolation ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Natural Period ◽  
Isolation System ◽  
Pendulum System ◽  
Base Isolation System ◽  
Friction Pendulum ◽  
Seismic Mitigation ◽  
Friction Pendulum System

In order to promote seismic resistance capability of structures and simplify the manufacturing processes of an isolator, a new base isolation system called the multiple trench friction pendulum system (MTFPS) is proposed. The investigations for the proposed isolator have been carried out to address its mechanical characteristics and to assess its performance in seismic mitigation through a series of shaking table tests in this study. The MTFPS isolator can provide different natural periods, displacement capacities and damping effects in any two independent directions. The natural period and damping effect for a MTFPS isolator change continually during earthquakes. Results from the shaking table tests on a scaled three-story structure isolated with MTFPS isolators illustrate that the proposed MTFPS isolator can isolate most earthquake induced energy and provide good protection for structures from earthquake damage. In addition, the mathematical formulations for the MTFPS isolator have also been derived to examine its characteristics.

SEISMIC CAPACITY OF MEDIUM SIZE CONTINUOUS BRIDGES WITH LEAD-RUBBER BEARINGS

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 199-206
Author(s):  
Bertha Olmos ◽  
José Jara ◽  
José Luis Fabián
Keyword(s):  
Seismic Performance ◽  
Seismic Vulnerability ◽  
Base Isolation ◽  
Elastic Behaviour ◽  
Medium Size ◽  
Nonlinear Behaviour ◽  
Seismic Capacity ◽  
Damage Scenarios ◽  
Isolation Systems ◽  
Rubber Bearings

This paper investigates the effects of the nonlinear behaviour of isolation pads on the seismic capacity of bridges to identify the parameters of base isolation systems that can be used to improve seismic performance of bridges. A parametric study was conducted by designing a set of bridges for three different soil types and varying the number of spans, span lengths, and pier heights. The seismic responses (acceleration, displacement and pier seismic forces) were evaluated for two structural models. The first model corresponded to the bridges supported on elastomeric bearings with linear elastic behaviour and the second model simulated a base isolated bridge that accounts for the nonlinear behaviour of the system. The seismic demand was represented with a group of twelve real accelerograms recorded on the subduction zone on the Pacific Coast of Mexico. The nonlinear responses under different damage scenarios for the bridges included in the presented study were estimated. These results allow determining the seismic capacity of the bridges with and without base isolation. Results show clearly the importance of considering the nonlinear behaviour on the seismic performance of bridges and the influence of base isolation on the seismic vulnerability of medium size bridges.

Dynamic Characteristics of Base-Isolated Steel Frame under Seismic Ground Motion

2011 ◽  
Vol 255-260 ◽  
pp. 2341-2344
Author(s):  
Mohammad Saeed Masoomi ◽  
Siti Aminah Osman ◽  
Ali Jahanshahi
Keyword(s):  
Ground Motion ◽  
Base Isolation ◽  
Time History ◽  
Steel Structure ◽  
Steel Structures ◽  
Steel Frame ◽  
Nonlinear Time History Analysis ◽  
Seismic Load ◽  
Vector Method ◽  
Seismic Ground Motion

This paper presents the performance of base-isolated steel structures under the seismic load. The main goals of this study are to evaluate the effectiveness of base isolation systems for steel structures against earthquake loads; to verify the modal analysis of steel frame compared with the hand calculation results; and development of a simulating method for base-isolated structure’s responses. Two models were considered in this study, one a steel structure with base-isolated and the other without base-isolated system. The nonlinear time-history analysis of both structures under El Centro 1940 seismic ground motion was used based on finite element method through SAP2000. The mentioned frames were analyzed by Eigenvalue method for linear analysis and Ritz-vector method for nonlinear analysis. Simulation results were presented as time-acceleration graphs for each story, period and frequency of both structures for the first three modes.

scholarly journals Analytical Evaluation of MCE Collapse Performance of Seismically Base Isolated Buildings Located at Low-to-Moderate Seismicity Regions

2020 ◽  
Vol 10 (24) ◽  
pp. 9150
Author(s):  
Hyung-Joon Kim ◽  
Dong-Hyeon Shin
Keyword(s):  
Base Isolation ◽  
Numerical Models ◽  
Influential Factors ◽  
Collapse Mechanism ◽  
Total System ◽  
Practical Applications ◽  
Seismic Design Code ◽  
Moderate Seismicity ◽  
Design Requirements ◽  
Isolation Systems

The promising seismic response emerged by the concept of base isolation leads to increasing practical applications into buildings located at low-to-moderate seismicity regions. However, it is questionable that their collapse capacities can be ensured with reasonable reliability, although they would be designed according to a current seismic design code. This paper aims to investigate the collapse capacities of isolated buildings governed by the prescribed design criteria on the displacement and strength capacities of the employed isolation systems. In order to evaluate their collapse capacity under maximum considered earthquakes (MCEs), simplified numerical models are constructed for a larger number of nonlinear incremental dynamic analyses. The influential factors on the collapse probabilities of the prototype buildings are found out to specifically suggest the potential modifications of the design requirements. Although the MCE collapse probabilities of all isolated buildings are smaller than those expected for typical non-isolated buildings, these values are significantly different according to the degree of seismicity. The MCE collapse probabilities are dependent upon the governing collapse mechanism and the total system uncertainty. For the prototype buildings located at low-to-moderate seismicity regions, this study proposed the acceptable uncertainty to achieve a similar collapse performance to the corresponding buildings built at high seismicity regions.

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

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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