ABOUT THE INTERNATIONAL CONCRETE ABSTRACTS PORTAL

  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal

Showing 1-5 of 8 Abstracts search results

Document: 

SP271

Date: 

July 1, 2010

Author(s):

Editors: Pedro F. Silva & Raj Valluvan / Sponsored by: ACI Committee 341

Publication:

Symposium Papers

Volume:

271

Abstract:

This CD-ROM consists of seven papers that were presented at a session sponsored by ACI Committee 341 at the ACI Fall Convention in St. Louis, MO, in November 2008. The papers focus on the most recent advancements in performance-based seismic design of reinforced concrete bridges, including analytical and experimental studies, and design and construction practices with relevant information related to reinforced concrete bridges based on performance-based design. Note: The individual papers are also available. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP-271

DOI:

10.14359/51663851


Document: 

SP271-04

Date: 

May 24, 2010

Author(s):

V. A. Suarez and M. J. Kowalsky

Publication:

Symposium Papers

Volume:

271

Abstract:

This paper reviews the Direct Displacement-Based Design Method for seismic design of bridges and compares it to the design procedure implemented in the AASHTO Guide Specification for LRFD Seismic Bridge Design. It is shown with examples that DDBD has several advantages that could be put to use as an alternative design method to that proposed in the AASHTO Guide Specifications for LRFD Seismic Bridge Design.

DOI:

10.14359/51663890


Document: 

SP271-03

Date: 

May 24, 2010

Author(s):

O. Kwon, A. M. Mwafy, and A. S. Elnashai

Publication:

Symposium Papers

Volume:

271

Abstract:

The multi-limit state seismic design and evaluation procedure allows structures to satisfy different performance criteria against different levels of seismic excitation. To achieve the simultaneous satisfaction of the multi-level design approach, it is essential to employ accurate analysis procedures which can be consistently applied to various levels of ground motions. In this study, several analytical evaluation procedures are compared via the application of the methods to two bridge structures. In the first application, a bridge considered typical of the inventory in the Central and Eastern United States is analyzed. Inelastic Response History Analysis (IRHA), two Capacity Spectrum Methods (CSMs), two Elastic Response History Analysis (ERHA) approaches with different stiffness approximation, and SDOF simulations are conducted. The second and more complex application, a 59-span irregular bridge crossing the Mississippi River is also analyzed in the elastic and inelastic ranges. Results from IRHA and simplified analysis procedures are compared to assess their applicability and limitations. It is concluded that the approximate methods have limited applicability, which depends on several parameters including intensity of ground motions and characteristics of bridge structures. The importance of inelastic and dynamic analysis in seismic assessment is emphasized, while cases where the simplified procedures yield acceptable response are presented.

DOI:

10.14359/51663889


Document: 

SP271-07

Date: 

May 24, 2010

Author(s):

T. L. T. Nguyen, P. F. Silva, M. T. Manzari, and A. Belarbi

Publication:

Symposium Papers

Volume:

271

Abstract:

In the last two decades, seismic design of reinforced concrete bridges has shifted from a purely “life-prevention” design approach to a broader approach that also addresses “damage control” and “loss reduction” issues. This shift in philosophy requires the use of numerical tools that more accurately simulate the response of various bridge components. As importantly, a greater emphasis is placed on understanding the effects that these bridge components have on the overall seismic response of bridges. This paper presents the results of a series of nonlinear time history analyses of a RC bridge that was simulated under various modeling conditions using a finite element program called Opensees. These time history analyses were performed according to the following 16 modeling conditions: (a) two options for the nonlinear modeling of the columns, (b) two modeling conditions at the bridge columns’ foundation, and (c) four types of modeling conditions at the bridge abutments. Additionally, these modeling conditions were evaluated under two design earthquake levels that characterize the maximum considered earthquake and the frequent earthquake. To enforce the analysis, two more earthquake records were used: Inca-Peru and Northridge. Analytical results confirm that the various modeling options have significant influence on the seismic response of bridge systems, especially when nonlinear response of the abutment shear keys are included in the analyses. The different modeling runs were numerically evaluated and compared to each other in terms of the displacement ductility imposed on the columns. Within a performance-based design methodology, detailed results from these analyses are presented and discussed in further detail in the paper.

DOI:

10.14359/51663893


Document: 

SP271-06

Date: 

May 24, 2010

Author(s):

K. R. Mackie, J.-M. Wong, and B. Stojadinovic

Publication:

Symposium Papers

Volume:

271

Abstract:

Post-earthquake repair costs and repair times are important for evaluating the performance of new bridge designs and existing bridges in regions where bridges are subject to seismic hazards. Hazard and structural demand models describe the probabilistic structural response during earthquakes. Damage and decision models link the structural response to decisions on bridge repair actions and repair costs. A step-by-step probabilistic repair cost and repair time methodology is proposed in this paper to probabilistically evaluate repair metrics for different bridge components and the bridge as a system, corresponding to varying degrees of damage. Repair actions, quantities, times, and costs are input into spreadsheet templates, and a numerical tool evaluates the expected value and variance of both repair costs and repair times for a range of earthquake intensities. This methodology uses the concept of performance groups—groups defined to account for bridge components that are repaired together. Spreadsheets are used to track all the necessary data: bridge information, structural response, component damage states, repair methods and repair quantities, and unit costs or production rates. Data can be customized for repair methods and bridge types particular to different regions. A multi-span, reinforced concrete highway overpass bridge in California is used to illustrate the methodology.

DOI:

10.14359/51663892


12

Results Per Page 




Please enter this 5 digit unlock code on the web page.