Credit: Steven Fulmer
Steel pipe testing material stands at NCSU's Constructed Facility Laboratory in November 2010 as part of a project investigating the impact of seismic loading history on the design of reinforced concrete bridge columns typically used in Alaska.
| AUTC Project Number |
410002 |
| Principal Investigator |
Mervyn Kowalsky (NCSU) kowalsky@ncsu.edu |
| Funding Agency |
US Department of Transportation (RITA) Alaska Department of Transportation & Public Facilities |
| Project Budget |
USD 303,440 |
| Start Date |
1 July 2010 |
| Estimated End Date |
31 December 2011 |
Abstract
This project investigates the impact of seismic loading history on the design of reinforced concrete bridge columns typical of those used in Alaska. Currently, structural engineers use concrete and steel strain limit states in seismic design, which have minimal experimental or theoretical basis. The overall objective of this project is to propose strain limit states that account for regional seismic loading histories in Alaska, and to relate these proposed strain limits to displacement limits. Project goals will be met through a combination of analytical and experimental studies. A key requirement of the experimental work is the ability to measure large strains (up to 12%). The seismic loading histories to which the test specimens will be subjected will be determined from a data set developed by researchers at the University of Alaska Anchorage. Results from both frame-type and fiber-based analyses using ground motions from the data set will guide the initial selection of specimen design variables. A total of nine tests on essentially full-scale circular bridge columns will be performed. Given the limited number of tests, it is important to learn as much as possible from each test before designing and conducting additional 9 tests. These nine test units will be subjected to load histories with varying characteristics, but typical of those experienced in Alaska. The primary benefit of this project will be a better understanding of how seismic load history influences the performance of reinforced concrete bridges in Alaska. ADOT&PF engineers will be provided with tools to refine bridge designs, optimizing for regional seismicity and ensuring that bridges in Alaska remain safe in major earthquakes and serviceable in smaller earthquakes.
Related Project Activity
Effect of Load History History on Limit State on Columns
The project team presents the results of the project to date to the peer review panel. Three documents are provided: a PowerPoint presentation, Test 12 Summary and the Column Detailing for Tests 13-18. The results to date provide column performance for six earthquakes including the most recent Japanese earthquake and the Three Cycle Loading tests. The results show surprising similarities among the earthquakes.
Load History April Meeting 2011
Column Detailing for Tests 13-18
Test 12 Summary
Push Over Test
Credit: Chad Goodnight
Full scale push over test at North Carolina State University to test the response of a bridge column to an earthquake.
Test 11 Summary – Kobe Earthquake Load History
Results of load history testing on circular bridge columns using the Kobe earthquake load history. The report shows the column displacement history and resulting force vs displacement response. This is test 11 in the series of tests to understand how concrete bridge columns respond to a range of earthquake loadings.
test11_summary.pdf
Kowalsky Presents Update on Bridge Structures Project
Dr. Mervyn Kowalsky gave the following presentation, “Effect of Load History on Performance Limit States of Bridge Columns”. The presentation is available: sept2010_LH_bridgeColumns.pdf.
