Program for computing seismic hazard

Attenuation Table

Attenuation Table

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  • Last Post 12 November 2018
MagpieG4 posted this 24 September 2018

Dear friends,

I have encountered a severe problem regarding the format of the attenuation table. 

How can we create an attenuation table with a given GMPE with known constants with magnitude, distance, soil and focal mechanism type?

Is there a more detailed explanation of the construction of the attenuation table than the given one by the manual?

With regards,

Paul

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Content_Manager posted this 08 October 2018

Dear Paul,

In the R-CRISIS Help Menu is explained, in detail, how to build a attenuation table (R-CRISIS Help Menu -> Ground-motion prediction models -> Attenuation tables). However, I am attaching an example to show you how the structure of this file is.

  • Header:

The meaning of each row is the following (taken from R-CRISIS Help Menu):

 

  • Parameters defining the magnitude and distance limits and type:

Magnitude:

MINF, MSUP, NMAG 

Distance:

RINF, RSUP, NRAD, TYPE 

 

  • Intensity:

Intensities for structural period equals to 0.005s, sigma=0.7, Amax=0 (no truncation), CoefH=0.

Each row represents a magnitude and each column represents a distance.

Likewise, a similar intensities block is built to T=0.15s:

 

Intensities here presented are not real, they are random numbers only to show the structure of the file.

As can you see, in the attenuation table only magnitude and distance vary for each row and column, respectively. This means that soil and focal mechanism type are constant for all intensities here presented.

 

In the following link, you will find an example of Attenuation Table loadable in R-CRISIS. Keep in mind that intensities contained in this file are not real, they are random values.

Example of Attenuation Table

 

Thank you for your preference and interest in R-CRISIS.

 

Best regards,

 

Nikos Vavlas posted this 11 November 2018

Hello.

I have a few questions about inserting an attenuation table.

Do i need to insert the actual value of the intensity I, or its natural logarithm, Ln(i)? And how does R-CRISIS calculate the intensity of the intermediate values? For example, if i insert two magnitudes M=6 and M=7 how does the intensity that corresponds to M=6.5 result?

Thank you in advance.

Content_Manager posted this 12 November 2018

Dear Nikos,

Below, you will find the answer to your questions:

 

Do i need to insert the actual value of the intensity I, or its natural logarithm, Ln(i)?

You have to insert the actual value of the intensity I.

 

How does R-CRISIS calculate the intensity of the intermediate values?

For intermediate values, R-CRISIS interpolates between two known values.

 

I hope this solves your questions.

 

Thank you for your preference and interest in R-CRISIS.

 

Best regards,

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