Add support for vertical ground motions

Start with pure V/H based model Gülerce & Abrahamson (2011)

• @nkwong Determine which GMMs currently in use have coefficient tables, modified functional forms, or ground motion tables for vertical
• Implement container class for Gülerce & Abrahamson (2011): V/H GM
• Add config flag "vertical": false (default)

V/H models for consideration:

• Gulerce and Abrahamson 2011 from NGAW1
• Bommer et al 2011 for Europe and Middle East
• Akkar and Sandikkaya 2014 for Europe
• Bozorgnia and Campbell 2016 from NGAW2
• Haji-Soltani et al 2017 for CEUS

added GMM label

changed the description

marked the checklist item @nkwong Determine which GMMs currently in use have coefficient tables, modified functional forms, or ground motion tables for vertical as completed

changed the description

mentioned in issue #110

mentioned in issue #168 (closed)

@nkwong I was looking at the G&A model and the adjustment to the mean seems pretty straightforward but I'd like to double check my understanding with you. I also have questions about the aleatory variability of the model.

Hi Peter, happy to find time to chat further.

In the meantime, here are a few potentially helpful resources for clarifying implementation of this GMM:

1. Matlab-based implementation (here)
2. Earthquake Spectra paper on use of this GMM (attached)
3. Corresponding Appendix A on relating GMMs for V/H with those for H (attached)
4. Corresponding Appendix B on deriving CMS from GMM for V/H (attached)

2019_-Kwong_Chopra-Selecting_scaling_and_orienting_three_components_of_GMs_for_intensity_based_assessments_at_far_field_sites-_EQS.pdf

2019_-Kwong_Chopra-Selecting_scaling_and_orienting_three_components_of_GMs_for_intensity_based_assessments_at_far_field_sites_Appendix_A-_EQS.pdf

2019_-Kwong_Chopra-Selecting_scaling_and_orienting_three_components_of_GMs_for_intensity_based_assessments_at_far_field_sites_Appendix_B-_EQS.pdf

Simon

marked the checklist item Add config flag "vertical": false (default) as completed