News and Announcements

November 2009

NEES 4-Span Bridge- Model 3- Fiber-Reinforced Polymer (FRP) Composite Bridge 

Scheduled Testing: Spring 2010

The third model will incorporate another innovative design in the piers.  Similar to the previous models the bridge will be supported on three, two-column piers.  Two innovative ideas will be studied in this bridge: (1) All three piers in Model 3 will incorporate round reinforced concrete columns with FRP jackets, and (2) Accelerated bridge construction techniques and details will be utilized.  A different detail will be used in each pier.  In pier 1 the columns will consist of cast-in-place concrete-filled glass FRP tubes in which the tubes will serve as the formwork and will provide a part of the flexural and shear capacity and the entire required confinement.  The fibers will be in the +/- 55-degree angles.  Longitudinal steel bars will be anchored into the cast-in-place footing.  In pier 3 similar columns will be used but they will be precast and placed into a precast footing.  In both piers 1 and 3 the connection to the superstructure will consist of steel pipe pins.   Pier 2 will be made with segmental reinforced concrete columns wrapped with carbon FRP to provide confinement and shear capacity, with fibers in the transverse direction of the column.  The earthquake loading protocol will be similar to those used in bridge models 1 and 2.

November 2008

Saving Bridges with Innovation -

Earthquake Engineers at University of Nevada, Reno to Test 110-ft Bridge Model to Failure

Standard bridges are severely damage during strong earthquakes.  They are designed that way to keep their cost under control.  To save lives bridges are made so they do not collapse even though they are no longer usable.  The question is what is the impact of having to close numerous damaged bridges in a city like Los Angeles or San Francisco at a time when these bridges are needed the most for fire trucks, ambulances, and other emergency vehicles?  Solution- innovation! “Funded through a $2M research grant by the National Science Foundation and the Network for Earthquake Engineering Simulation (NEES), UNR research team is taking advantage of unique features of materials such as Nickel-Titanium alloys, polyvinyl fibers mixed with cement, and rubber materials to prevent damage and avoid bridge closure even when there a strong earthquake,” stated Prof. M. Saiidi, the Principal Investigator of the project.  The lead PhD student for the project is Carlos Cruz.  The testing is scheduled to start in early December and be completed on December 11, 2008.  The large magnitude testing will be webcast for public viewing.  Prof. Saiidi may be contacted at saiidi@unr.edu for more details.

Principal Investigators & Senior Personnel: M. Saiidi, G. Fenves (Univ. of Texas, Austin), A. Mirmiran (Florida International Univ.), A. Elgamal (Univ. of California, San Diego), I. Buckle (UNR), A. Kiremedjian (Stanford Univ.), G. Pekcan (UNR), N. Johnson (UNR)

Graduate & Undergraduate Students: C. Cruz (PhD), D. Hillis (MS), D. Smith (Sr.), A. Taheri (Jr.)

NSF Grant Numbers: CMS-0420347  

Shape memory Nickel-Titanium bars used in two of the columns

Another two columns incorporate elastomeric pads in critical sections

March 2008

4-span bridge model with advanced materials and details under construction

November 2007

Dr. Saiidi visits Florida International University to discuss the project with Dr. Mirmiran and observe testing of two-column pier made with concrete filled FRP elements.

July 2007

Robby Nelson, a graduate student working on the first 4-span bridge project, presents a summary of the NEES project to middle school students attending the earthquake engineering summer camp at the University of Nevada, Reno.

February 2007

We successfully tested the first 4-span bridge on February 12-15.  Approximately 250 visitors were in the lab and another 250 watched the test on the web.  Here is the link to an article by the Engineering News Record about the event http://www.enr.com/news/transportation/archives/070226a.asp. To watch the construction and test video clips visit http://nees.unr.edu/4-spanbridges/data.html.

January 2007

Davidson Academy Students Visit the NEESR 4-Span Bridge Model

On January 26, 2007, students and faculty from the Davidson Academy on the campus of the University of Nevada, Reno visited the structures laboratory to learn about the NSF NEESR project on shake table studies of 4-span bridges. Aged 10-16, the Davidson Academy students are considered "profoundly gifted" with extraordinary talent and educational needs. They have been featured on CNN and New York Times. The link to the institute's web site is: http://www.davidsonacademy.unr.edu/.

During the visit students learned about earthquake engineering of bridges and critical issues. They also visited the facilities of the earthquake engineering research laboratory.

December 2005

In preparation to use non-invasive photogrammetric methods in the 4-span bridge tests at UNR, Professor JoAnn Browning and Jeff Olafsen of the University of Kansas and their graduate students attempted their new data acquisition system on a single column tested on one of the UNR shake tables as a part of a study funded by Caltrans (PIs: Saiidi and Somerville; Caltrans Project Manager: El-Azazy). Professor Browning and Olafsen has received a NEESR payload grant to study the first 4-span bridge model to be tested at UNR ( http://nees.unr.edu/4-spanbridges/Browning.html ).

Figure 1: (L to R) University of Kansas graduate students Nick Hunt and Zeynep Firat with Prof. Browning next to the marked column.

Figure 2: (L to R) Zeynep Firat, Prof. Browning, Prof. Olafsen, and Nick Hunt.

August 2005

The National Science Foundation funded three payload projects to be conducted in the course of shake table studies of the four-span bridges.  The PIs for the payload projects are: Dr. Farhad Ansari, Dr. JoAnn Browning, and Dr. Reggie DesRoches.  More information on the payload projects is posted on our site.  Use the following link:

http://nees.unr.edu/4-spanbridges/payloadprojects.html

May 2005

In preparation to use advanced sensors in the 4-span bridge tests at UNR, Professor Anne Kiremidjian of Stanford University and Professor Farhad Ansari of the University of Illinois in Chicago attempted their new sensors on a single column tested on one of the UNR shake tables as a part of a study funded by Caltrans (PIs: Saiidi and Somerville; Caltrans Project Manager: El-Azazy).

Figure 1: (L to R) Rob Benco, Prof. Anne Kiremidjian, Pooya Sarabandi, and Dennis Perry and the wireless accelerometer developed at Stanford University with test column in the background.

Figure 2: (L to R) Adam Tennant, Asad Bassam, and Prof. Farhad Ansari examine the fiber optic sensors attached to the column.

April 2005

A project Advisory Board was formed. Please check the "Advisory Board" button in the home page for more information.

March 2005

The National Science Foundation awarded a supplemental grant for this project to provide research experience for undergraduate students (REU).  Through this supplement an undergraduate student will work with the PI, other senior investigators, and graduate students to conduct different tasks of the project.  Typically after gaining some experience in the conduct of research, REU students are assigned an independent research task that could lay the foundation for their graduate research.