ß Back to I-880 page

November 25, 2002

ADK. Carry out preliminary studies on a simple model. Kunnath will deliver preliminary Model II.  Not done.  Expect ~15 Apr 2003? 

December 02, 2002

Kunnath.  Deliver Models I and II.  Done.  Model I was one column in a bent.  Used to validate material model.  Might be of interest to Eberhard.  Checks that it works in terms of convergence.  Model II was delivered to ADK.  Model II is one bent.  Core model. Includes foundation springs (can turn on & off).  

December 20, 2002

Eberhard.  Provide expressions from regression analyses for use in I-880 columns related to drift and peak strain at onset of spalling and bar-buckling. Done.  Eberhard handed small document to Sashi at Palm Springs. 

Der Kiureghian, Kunnath.  Identify critical uncertainties.  Use sensitivity studies being conducted at UC Davis to identify those variables that are most sensitive to demand. Select material, modeling and other critical variables.  Not done, expect ~15 Apr. 

Stojadinovic.  Compile list of DVs related to loss modeling.  Done?

January 10, 2003

Fenves, Scott.  OpenSees module to compute tangential drift at inflection point.  Not done yet.  Procedure is written but not yet implemented.  Expect ~March 28 (per Scott email 21 Mar 2003). 

January 31, 2003

Kunnath.  Coordinate with Allin Cornell and other testbed managers (particularly the Humboldt Bay testbed) to see if additional IMs need to be considered. Alternative scaling procedures may be necessary depending upon the selected IMs, hence a decision must be reached as quickly as possible.

Kunnath. Discuss the issue of after-shocks with Somerville and establish a procedure for deriving potential after-shock data from existing records.

Kunnath. Develop expressions for drift and peak strain at initiation of shear cracking and significant loss of strength

Kunnath.  Deliver Model III.  Done.  Model III is one complete frame (frame 4 in I-880 model), 3 spans, 4 bents with one elastic beam.  Ends are either rollers or springs, with properties for the spings. 

Eberhard.  Develop expressions for drift and peak strain at initiation of shear cracking and significant loss of strength.  Not done as of 20 Mar 2003. Sashi will email Marc about this and cc me.  

February 28, 2003

Kunnath.  Validate models to check computation of system EDPs.

March 01, 2003

Kunnath. Continue calibration and validation tests of Model IV. Done.  Models 3 frames, including frame-frame interaction (frames 3, 4, and 5).  Sashi is using this one, but ADK doesn’t want anything more than Model II. 

March 28, 2003

Fenves, Scott. OpenSees module to compute tangential drift at inflection point.  Rescheduled from January 10, 2003. 

April 01, 2003

Kunnath.  Prepare draft report of simulation models and sensitivity studies.

Eberhard.  Complete written report (Chapter 6).