Site Specific Seismic Ground Motion Hazard Analysis 6-Week Short Course

Presented by Dr. Norm Abrahamson, UC Berkeley

Please join us as we launch our first on-line learning series! Dr. Norm Abrahamson will present a 6-week short course for CalGeo on Site Specific Seismic Ground Motion Hazard Analysis. Sessions will run each Friday starting May 22nd from 11am - 12:30pm. The last session will be Friday June 26th, 2020.

All webcasts will be recorded and available on CalGeo's new On-line Learning Library for course attendees. If you are unable to make all the live sessions, you will have full access to the online course. The online recorded course will also be available for purchase and include all sample problems and hand-outs.

Course Outline:

Session 1: Introduction

Background

i.    PSHA vs DSHA
ii.    What the PSHA software is doing
iii.   Understanding PSHA results

When is a site-specific is required with ASCE 7-16

How are site-specific code values determined
i.    Source model – UCERF3
     1.    Issue for implementation in hazard codes
     2.    Selecting the magnitude for deterministic scenario
     3.    Comparison of UCERF3 with fault-specific slip-rate and mag pdf
ii.    Ground-motion models
     1.    NGA-W2 models
     2.    Proper use of VS30
     3.    Basin effects (Z1, Z2.5)

Session 2: Background (part 2) and CMS:

How are site-specific code values determined (cont)
i.    Steps for design spectra
     1.    Develop UHS and Deterministic spectra
     2.    RotD50 to RotD100
     3.    Risk factors – apply to UHS
     4.    Check lower limits
     5.    take smaller of the two spectra
     6.    multiply MCE spectrum by 2/3 for DE spectrum

CMS
i.    Theory
ii.    How to use CMS for site-specific spectra per CBC
iii.    When should CMS be used

Session 3: Site response

When is this needed
i.    per CBC
ii.    when is this beneficial (i.e. when is the Vs profile from the GMPE appropriate)

Soil over rock vs Vs profile correction
i.    CBC approach
ii.    VS profile correction approach
     1.    Why this approach makes more physical sense
iii.    Example comparison if time

Overview of analysis methods (equivalent linear, nonlinear) and software
i.    (SHAKE, deepsoil, flac, STRATA – not getting super into detail)

Session 4: Directivity and time history selection

Theory of directivity
i.    Directivity models
     1.    Effect on the median GMPE
     2.    Effect on standard deviation of GMPE

How to apply directivity
i.    Range of approaches used in practice
ii.    Recommended approach
     1.    PSHA
     2.    DSHA

Directivity in time history selection
i.    Pulse motions approach
ii.    instantaneous power (IP) approach

How do you know if you selected a good set of time histories?
i.    Spectral shape
     1.    How much peak-to-trough variability should be included
ii.    Secondary parameters
     1.    Duration
     2.    PGV
     3.    Arias intensity
     4.    CAV

Session 5: Time history scaling and spectral matching

Theory:
i.    Scale factors
     1.    What do scale factors tell us about the ground motion
     2.    Use of limits on scale factors
ii.    Spectral matching
     1.    What is this doing?
     2.    Is spectral matching a good thing?

Application of Scaling method
i.    How much peak-to-trough variability should be in the final set?

Application of Spectral matching methods
i.    How to scale/spectrally match time histories with new CBC guidelines
ii.    Software that can do this

Session 6: Summary and Example Site-Specific Analysis

About the Instructor:

Dr. Abrahamson has been involved in strong motion seismology for 18 years. He has extensive experience in the practical application of seismology to the development of deterministic and probabilistic seismic criteria (response spectra, and/or time histories) for engineering design or analyses. He has been involved in developing design ground motions for hundreds of projects including dams, bridges, nuclear power plants, nuclear waste repositories, water and gas pipelines, rail lines, ports, landfills, hospitals, electric substations, and office buildings. About 3/4 of these projects have been in the Western US and the other 1/4 have been in the Eastern US or outside of the US.

As a consultant, Dr. Abrahamson has been involved in the ground motion studies for several major engineering projects in California. Recent projects include the Caltrans major toll bridge retrofit projects, the CalFed project for the Sacremento Delta levee system, the BART seismic retrofit project, and the SFO expansion. He has been involved in developing ground motion for nuclear plants and dams in the United States and in other countries. He served as the leader of the ground motion characterization team for the proposed high level nuclear waste repository at Yucca Mountain.

Benefits of attending the live webcasts:

Attendees to the live webcasts will be able to ask questions for about 10-minutes at the conclusion of each session. On-line recordings will be available within 1-2 days after each session.

How to register:

As this course is highly valuable, we have a three-step registration process:

1. Click on the link below and complete payment. You may register more than one person from your company.
2. EACH paid attendee will need to register for the GoToWebinar sessions. A link and password will be provided on the confirmation page after payment is completed as well as sent in a confirmation e-mail.
3. CalGeo staff will confirm your GoToWebinar registration and approve you for the session.

Please note: Once payment is processed, your CalGeo login e-mail will give you access to the recorded sessions and materials in our new On-line Learning Library. Only individuals who have paid and registered for the course will have access to the on-line recordings for up to 1-year.

Cost: Members $375, Non-members $750

Group Discount: If 5 or more people from one member company register they will receive a discount price of $300/pp! Use the code: 5ORMORE at checkout for the discount. Registrations can come in separately as long as there are 5 or more total from one company.

Pay for SHA Course

Don't forget to click on the link on the confirmation page or the confirmation e-mail to register using GoToWebinar for the live 6-week webseries!