EFFECT OF SITE AMPLIFICATION ON SEISMIC SAFETY EVALUATION OF FLYOVER PIER

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohammad Raihan Mukhlis ◽  
Md. Abdur Rahman Bhuiyan
Keyword(s):  
Failure Modes ◽  
Pushover Analysis ◽  
Safety Evaluation ◽  
Time History ◽  
Site Amplification ◽  
Shear Capacity ◽  
Main Concern ◽  
Seismic Safety ◽  
Displacement Ductility ◽  
Seismic Safety Evaluation

Bangladesh is a developing country in which a lot of multi-span simply/continuous supported flyovers are being constructed in its major cities. Being situated in a seismically active region, seismic safety evaluation of flyovers is essential for seismic risk reduction. Effects of site amplification on seismic safety evaluation of flyover piers are the main concern of this study. In this regard, failure mode, lateral strength and displacement ductility of piers of a typical multi-span simply supported flyover have been evaluated by Japan Road Association (JRA) recommended guidelines, with and without considering site amplification. Ultimate flexural strengths of piers have been computed using the pushover analysis results. Shear capacity of piers have been calculated using the guidelines of JRA. Lateral strengths have been determined depending on the failure modes of the piers. Displacement ductility of piers has been computed using yield and ultimate displacements of the piers obtained from the pushover analysis results. Selected earthquake time history is used in seismic safety evaluation of the flyover piers. Finally, the ductility design method is used to conduct the seismic safety evaluation of the piers with and without considering site amplification. From the numerical results, it has been revealed that the effects of site amplification on seismic safety evaluation of bridge structures should be carefully taken into account.

scholarly journals A Multilevel Approach for the Cultural Heritage Vulnerability and Strengthening: Application to the Melfi Castle

Buildings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 158
Author(s):  
Cristina Cantagallo ◽  
Enrico Spacone ◽  
Daniele Perrucci ◽  
Nicola Liguori ◽  
Clara Verazzo
Keyword(s):  
Structural Integrity ◽  
Seismic Analysis ◽  
Pushover Analysis ◽  
Historical Analysis ◽  
Safety Evaluation ◽  
Soil Survey ◽  
Seismic Safety ◽  
Seismic Safety Evaluation ◽  
Cracking Pattern ◽  
Integrity Analysis

This study outlines a procedure for the seismic safety evaluation of historical buildings for engineers and architects that commonly work on buildings belonging to cultural and architectural heritage. The procedure is characterized by two interrelated phases: (a) building knowledge acquisition and (b) structural behavior analysis and safety assessment. The seismic safety evaluation strongly depends on the first phase, whose data can be obtained according to a multi-disciplinary approach based on five steps: (1) critical-historical analysis; (2) photographic documentation and geometrical survey; (3) structural identification and material survey; (4) foundation and soil survey; and (5) cracking pattern and structural integrity analysis. The proposed method was applied to the evaluation of the seismic safety of the Castle of Melfi (PZ, Italy). Comprehensive and multi-disciplinary knowledge of this monument greatly facilitated an accurate seismic analysis of this monument, which was conducted both at a local and global level using a linear kinematic analysis and non-linear static (pushover) analysis, respectively.

scholarly journals A Modified Newmark Methodology for Permanent Deformation Analysis of Rock-Fill Dams

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Hongjun Li ◽  
Hong Zhong ◽  
Zuwen Yan ◽  
Jianming Zhao
Keyword(s):  
Shear Strength ◽  
Safety Evaluation ◽  
Time History ◽  
Deformation Analysis ◽  
Vertical Acceleration ◽  
Seismic Safety ◽  
Critical Acceleration ◽  
Cyclic Shear ◽  
Rock Fill ◽  
Seismic Safety Evaluation

Newmark sliding block approach has been extensively studied by many researchers in the past decades. Significant progress has been made to alleviate its deficiencies and overcome its simplifying assumptions, but some aspects such as the cyclic shear strength and time history vertical acceleration in the Newmark sliding displacement analysis are seldom considered strictly. In the presented research, a modified Newmark methodology for sliding deformation analysis of rock-fill dams subjected to strong earthquake is proposed. In order to make the seismic safety evaluation of dams more realistic, the influence of cyclic shear strength (earthquake-induced reduction of shear strength) and time history vertical acceleration obtained from the dynamic response analysis on the critical acceleration and accumulative sliding displacement of the flexible sliding body is considered. Detailed comparison between the proposed method and existing methods is performed via the analysis of two typical dams, that is, a virtual rock-fill dam with a height of 100 m which is assumed to be situated on rock formation and a real core rock-fill dam with a height of 150 m built on deep overburden layers. It is demonstrated that the cyclic shear strength and time history vertical acceleration within flexible sliding body, as highlighted in the proposed method, have significant effect on the seismic safety evaluation, critical acceleration, and accumulation of sliding deformation of rock-fill dams subjected to strong earthquake loading. The existing approaches tend to provide unconservative evaluation on the consequences of earthquakes on rock-fill dams.

The Improvement Ways to Equivalent Linearization Method Based on the Difference between Results of Two Programs in Moderate Weak Site

2014 ◽  
Vol 919-921 ◽  
pp. 973-976
Author(s):  
Xiao Bo Yu ◽  
Rui Sun ◽  
Shang Jiu Meng
Keyword(s):  
Shear Strain ◽  
Safety Evaluation ◽  
Linearization Method ◽  
Shear Capacity ◽  
Equivalent Linearization ◽  
Computation Method ◽  
Seismic Safety ◽  
Short Period ◽  
Seismic Safety Evaluation ◽  
Equivalent Linearization Method

Equivalent linearization method is widely used in seismic response analysis. For Chinese engineers and researchers, LSSRLI-1 and SHAKE2000 are good choices for seismic safety evaluation. There is large difference between the results of these two programs in moderate weak sites, which directs ways to improve them. The average spectrum ratio increases with response spectrum peak value of inputting wave moving from long period to short period. The shear strain obtained by the programs exceeds shear capacity, which is impractical. In the type III site, the weak foundation exacerbates the error. In the way to improvement, frequency components of inputting wave should be taken into account, and a further study on computation method of strain should be launched. For security purposes, seismic safety evaluation for major projects needs multiple method for reliability, especially constructions sensitive to shear strain.

Seismic Safety Evaluation for Mountainous Highway Bridge Based on Risk Matrix

2011 ◽  
Vol 255-260 ◽  
pp. 4212-4216
Author(s):  
Gong Yuan Xie ◽  
Zhang Yue
Keyword(s):  
Seismic Design ◽  
Seismic Risk ◽  
Control Method ◽  
Safety Evaluation ◽  
Technical Support ◽  
Highway Bridge ◽  
Risk Matrix ◽  
Seismic Safety ◽  
Seismic Safety Evaluation

Risk matrix is applied to evaluate seismic risk on mountainous bridge. In this article, a continuous bridge is used as example to analyze the seismic risk of key position under a usual earthquake. Related control method is proposed to provide technical support for bridge seismic design and operation maintenance.

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