BridgePBEE*

BridgePBEE is a PC-based graphical pre- and post-processor (user-interface) for conducting Performance-Based Earthquake Engineering (PBEE) studies for bridge-ground systems (2-span single column). The three-dimensional (3D) finite element computations are conducted using OpenSees developed by the Pacific Earthquake Engineering Research Center (PEER). The analysis options available in BridgePBEE include: 1) Pushover Analysis, 2) Base Input Acceleration Analysis, and 3) Full Performance-Based Earthquake Engineering (PBEE) Analysis.

*Lu, J., Mackie, K.R., and Elgamal, A. (2011). BridgePBEE: OpenSees 3D Pushover and Earthquake Analysis of Single-Column 2-span Bridges, User Manual, Beta 1.0.

Download & Install BridgePBEE

Note: BridgePBEE only works on Windows based PC computers. It is best to use a relatively new Laptop or Desktop with a fast processor, and at least 2GB of memory.

The following steps describe how to download, install and run BridgePBEE. For detailed documentation, please see the user manual (10.5 MB pdf file, updated Dec 2011). In addition, a few demo examples are available at the Examples page.

Step 1: Install Tcl

If you have not installed Tcl/Tk on your computer, please download the Tcl/Tk 8.5 installation file below and double-click to install it (OpenSees employs Tcl 8.5). You only need to do this step once for a given PC.

Download Tcl 8.5

Step 2: Install Java

Most likely you already have Java installed on your computer. If you don’t, please download the installation file below and install the Java software.

Download Java

Step 3: Install BridgePBEE

Please download the installation file from the link below, and then double-click on the icon and follow the simple installation instructions (you may wish to visit this site periodically to check for updates).

Register/login to download BridgePBEE Installation File (Beta 1.1, updated 5/1/12)

Step 4: Run BridgePBEE

1) After installing the software on your computer, double-click the BridgePBEE icon to start.

2) To conduct a pushover analysis, click Pushover Analysis in the main window. To conduct single earthquake motion analysis or PBEE analysis, click Ground Shaking. For the default mesh, a typical Pushover analysis will be performed in about 5 minutes or less, and a typical earthquake simulation will consume about 10 – 60 minutes. For earthquake analysis with bridge on a rigid base (please see the Examples page), the runs will be very fast (about 5 minutes each). It is recommended first to do simpler runs such as the bridge on a rigid base earthquake scenario (particularly when exploring a full PBEE analysis with 100s of earthquake motions).

3) To open an existing model, click File in Menu and then click Open Model to open a model (the model file must have an extension of .pbe).

4) Click Execute in Menu and then click Save Model & Run Analysis to conduct the finite element simulation.

Step 5: Download BridgePBEE User Manual

BridgePBEE User Manual (10.5 MB pdf file, updated Dec 2011)

This manual includes sections on:

1) Input Interface, Pushover, and earthquake Analysis.

2) Output Interface: For pushover analysis or single earthquake motion analysis, the output interface in BridgePBEE includes Bridge Column Response Time Histories and Profiles, Column Response Relationships, Abutment Responses, and Deformed Mesh.

3) For PBEE analysis scenarios: i) Eleven different intensity measures and response spectra for each input motion are calculated on the fly and are available for display in table and plot formats. After conducting the PBEE analysis eleven different Performance Group (PG) Quantities are also available. In addition Ground surface and Bridge Peak Accelerations (for all motions) are also available to display against any of the eleven intensity measures. Note that the PG quantities can be displayed against the base shaking intensity measures or alternatively against the computed ground surface motions intensity measures.

Below are the 11 Performance Groups (PGs):
PG1: Max tangential drift ratio SRSS (col)
PG2: Residual tangential drift ratio SRSS (col)
PG3: Max long relative deck-end/abut disp (left)
PG4: Max long relative deck-end/abut disp (right)
PG5: Max absolute bearing disp (left abut)
PG6: Max absolute bearing disp (right abut)
PG7: Residual vertical disp (left abut)
PG8: Residual vertical disp (right abut)
PG9: Residual pile cap disp SRSS (left abut)
PG10: Residual pile cap disp SRSS (right abut)
PG11: Residual pile cap disp SRSS (col)

Finally, values of the above PGs will trigger certain repairs according to an embedded logic (that is actually mostly automatically modified according to the specified model properties such as percent steel in the bridge column or size of gap between bridge and abutment). The necessary repairs are defined by 29 prescribed repair quantities. Each quantity contributes to an already defined level to the overall repair cost as dictated by the PG values.

Click here to view the 29 repair quantities

The final results will be displayed against any of the 11 available intensity measures (for each employed earthquake motion)in terms of:
* Contribution to expected repair cost ($) from each repair quantity
* Contribution to repair cost std. dev. ($) from each repair quantity
* Contribution to expected repair cost ($) from each performance group
* Total repair cost ratio (%)
* Total repair time (CWD) where CWD stands for Crew Working Day
* Contribution to expected repair time (CWD) from each repair quantity

4) Hazard Assessment for Any User Specified Geographic Location:
The user is also able to specify a Seismic Hazard for a particular geographic location of this bridge system in terms of specified values for any IM (e.g., derived from USGS seismicity maps). Based on this local site Seismic Hazard, losses are estimated and displayed graphically as:
* The defined local site Hazard curve as a Mean annual frequency of exceedance (ground motion)
* Mean annual frequency of exceedance (Loss) against total repair cost ratio
* Return period against total repair cost ratio

5) Mesh Generation: This section describes how to build the finite element mesh in BridgePBEE.