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Overview

This page is intended to help users get their own bridge fragilities into Ergo. The information you will find in this document is:

  • File Types and Format
  • Field Descriptions

File Types and Format

There are two acceptable formats, comma separated value (CSV) and Extensible Markup Language (XML). The simplest way to get fragilities into Ergo is the CSV format which will internally be changed to XML. Both formats will be explained in their own section after the field descriptions.

Field Descriptions

In this section we will provid the expected field name, a short description about the field, the type for the field, whether the field is informational (e.g. for display or perhaps later use), and if any field has a small finite number of acceptable input values, they will be specified in the Acceptable Values column of the table. One information field is the Codecolumn which simply tells the user if the fragility was intended as a retrofit and if so, what type.

Field Name

Field Description

Field Type

Acceptable Values

Informational

ID

Unique numeric identifier in the fragility dataset

Integer

N/A

No

Author

Identifies the person(s) who provided each fragility set.

String

N/A

Yes

Structure Type

Structure Type this fragility curve is designed for

String

N/A

Yes

Description

A textual description providing information about the derivation of this fragility curve set

String

N/A

Yes

Ground Motions

Ground motion records used for time-history analyses when constructing fragilities

String

N/A

Yes

Code

Design code for the fragility set

String

low - no retrofit, seat extender, steel jacket, Restrainer cables, Shear Key, Elastomeric Bearing

Yes

Damage Type

The type of damage type this fragility represents

String

Structural

Yes

Demand Type

The demand type required by the fragility, can include the period if applicable (e.g. 0.2 Sa )

String

PGA, PGV, PGD, Sa, Sd, Sv

No

Demand Units

The units of the demand type

String

g (typically), could be other values if another demand type is specified

No

Limit States

The limit states of the fragility curves, Ergo expects 4 limit states. This tells Ergo how many fragility curves to expect.

String

Slight: Moderate: Extensive: Complete

No

Equation Type

The fragility equation type

Integer

1 - Lognormal distribution, 2 - Normal Distribution

No

Parameters

The number of fragility parameters present (should be 2 parameters per fragility, median and beta)

Integer

N/A

No

Median0First fragility median valueDoubleN/ANo
Beta0First fragility beta valueDoubleN/ANo
Median1Second fragility median valueDoubleN/ANo
Beta1Second fragility beta valueDoubleN/ANo
Median2Third fragility median valueDoubleN/ANo
Beta2Third fragility beta valueDoubleN/ANo

After the Parameters field, specify the fragility parameters for each curve. Each curve should have a pair of parameters and the keyword for the fields are the words Median and Beta followed by a number that specifies which curve the parameter belongs to. Number should start at zero so if we have 2 fragility curves, the following 4 additional fields would be in the file:

Median0, Beta0, Median1, Beta1, Median2, Beta2, Median3, Beta3

Example CSV File

Below is a sample CSV fragility for a bridge. The first row is column names, the second row is column types (reserved for later use, but currently just ignored) and the 3rd row is a set of 4 fragility curves for an MSC_Concrete bridge.

ID

Author

Structure Type

Description

Ground Motions

Code

Damage Type

Demand Type

Demand Units

Limit States

Equation Type

Parameters

Median0

Beta0

Median1

Beta1

Median2

Beta2

Median3

Beta3

Int

String

String

String

String

String

String

String

String

String

Int

Int

Double

Double

Double

Double

Double

Double

Double

Double

1

HAZUS

MSC_Concrete

As-built Fragility

Unknown

Low

Structural

pga

g

Slight: Moderate: Extensive: Complete

2

8

0.6

0.6

0.88

0.6

1.17

0.6

1.53

0.6

You can download the csv file here.

Example XML File

Below is the XML version of the CSV file.

 

<fragility-dataset>
  <fragility-dataset-sets>
    <fragility-set>
      <fragility-set-properties Parameters="8" DemandUnits="g" Description="As-Built Fragility" DamageType="Structural" EquationType="2" GroundMotions="Unknown" StructureType="MSC_Concrete" LimitStates="Slight: Moderate: Extensive: Complete" Author="HAZUS" ID="1" DemandType="pga" Code="Low"/>
      <fragility-set-labels>
        <fragility-set-label>Slight</fragility-set-label>
        <fragility-set-label>Moderate</fragility-set-label>
        <fragility-set-label>Extensive</fragility-set-label>
        <fragility-set-label>Complete</fragility-set-label>
      </fragility-set-labels>
      <fragility-set-fragilities>
        <fragility-curve fragility-curve-median="0.6" fragility-curve-beta="0.6" fragility-curve-type="Normal"/>
        <fragility-curve fragility-curve-median="0.88" fragility-curve-beta="0.6" fragility-curve-type="Normal"/>
        <fragility-curve fragility-curve-median="1.17" fragility-curve-beta="0.6" fragility-curve-type="Normal"/>
        <fragility-curve fragility-curve-median="1.53" fragility-curve-beta="0.6" fragility-curve-type="Normal"/>
      </fragility-set-fragilities>
    </fragility-set>
  </fragility-dataset-sets>
</fragility-dataset>

 


Ingest Sample Fragility

After downloading the bridge fragility csv file, follow the steps below to ingest it into Ergo:

Go to the File menu near the top of the application and select Import > Data. This will open the import wizard.

Expand the folder Data, select Dataset and click Next.

Where it says Select One, select Fragility and click Next.

Click Browse and locate the sample fragility dataset you downloaded and click Next. Please note, if you don't see the CSV file in the browse dialog, make sure the *.csv filter is selected.

Where it says Select the data type for this file select Bridge Fragilities and click Next.

Where it says Repository to ingest to select from the list of repositories, where it says Descriptive name for this dataset enter something like Sample Bridge Fragility and give it a version. Click Finish when done. The dataset should be available in the repository you selected under Bridges > Bridge Fragilities.

Conclusion

Now that you have some fragility data in Ergo, the next step is to learn about applying those fragilities to bridges. This will be discussed in the Bridge Fragility Mapping page. We have purposefully kept a weak coupling between fragilities and bridges to provide users with the flexibility to apply the fragilities in either very simplistic ways or very complex ways through the fragility mapping.

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