Development of a Community Shear-Wave Velocity Database in California

Sean AhdiUCLA Civil & Environmental EngineeringSCEC Workshop on Nonlinear Shallow

Crust Effects – 7/6/20171

Overview

• Introduction and Project Motivation• Data Types and Sources• Database Structure and Presentation• Applications and Impact

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INTRODUCTION AND PROJECT MOTIVATION

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Introduction

• Shear-wave velocity (VS) is widely recognized as a critical parameter for ground motion and ground failure studies

• Applications include:

– Geotechnical: 1D ground response analyses; liquefaction

– Seismological: Nonlinear seismic crustal models (e.g., SCEC Community [Crustal] Velocity Model Geotechnical Layer)

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Project Motivation

Goal: Develop open-access shear-wave velocity profile database for the United States.

Why?

• Many VS profiles have been measured in the US…

… but there is no medium for data access, visualization, andanalysis

• Many other countries have such a resource (Japan, Taiwan, Greece, Canterbury NZ, …)

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Focus: California

DATA TYPES AND DATA SOURCES

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Data Types

• Minimum criteria: any site with VS profile measured from a credible geophysical method with known geodetic coordinates.

– Include dispersion curves for surface-wave measurements

– Exclude: correlations to penetration resistance and lab-measured VS

• Optional data/metadata include:

– Co-located VP profiles, boring logs, SPT/CPT measurements, HVSR

– Others: elevation, slope, geology, site plans, ....

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Data Types

• Geophysical methods include:

– Invasive: down-/cross-hole, P-S suspension logging, seismic CPT

– Non-invasive: SASW, MASW, MAM, P- and S-wave seismic refraction

• Exclude ReMiTM (for now) and CXW methods

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Data Sources

• Federal Agencies: USGS Open File Reports, including VS30 and CPT databases; USACE Dam sites

• Network for Earthquake Engineering and Simulation (NEES); Resolution of Site Response Issues in the Northridge Earthquake (ROSRINE)

• California State Agencies: Dept. Water Resources levees; Division of Dam Safety; Caltrans bridges; CA Geological Survey: hospitals (OSHPD) and schools

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Data Sources

• UCLA Research reports: 100+ sites, 1971 Sylmar EQ

• Woodward-Lundgren & Associates reports (1973): 78 sites

• Law-Crandall (AMEC-FW): 363 sites in L.A.; proprietary data

• Other potential sources: utilities, private industry

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Digitized California Data (to Date)

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Data Source Reference No. Profiles Methods Information to be stored

USGS SCPT Database Holzer et al. (2010) 327 SCPT Coordinates, VS, qt, fs, SBT index, PWP

USGS OFR 2013-1102 Yong et al. (2013) (ARRA Report)

187 Multi-Method: SASW, MASW, MAM, ReMi, seis. refr., HVSR

Coordinates, Geology, VS, Inferred VP, Assumed density, Assumed poison's ratio

NEEShub NEES @ UTexas (2015)

15 SASW Coordinates, VS, VP

USGS OFR 2010-1168 Thompson et al. (2010)

53 SASW Coordinates, Dispersion data, VS

USGS OFR 2005-1365a&b Kayen et al. (2005a&b)

13 & 59 SASW Coordinates, Dispersion data, VS

Caltrans Bridge sites Unpublished 288 P-S Suspension Logging Coordinates, VS, VP

USGS OFR 03 -191: VSProfile Compendium

Boore (2003) 277 Downhole; Crosshole Coordinates, VS, VP, Poisson’s ratio, SPT, lithology

ROSRINE Nigbor et al. (2001) 50 Susp. Logging; SASW

CA DWR Levees Unpublished 28 SCPT

CA DWR DSOD Unpublished 26+ sites Various

CGS Hospitals & Schools Unpublished 103 sites Various

Modified from Shamsher Sadiq

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1156 digitized in USA to dateFrom Shamsher Sadiq

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DATABASE STRUCTURE AND PRESENTATION

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Database Structure

• Data are in disparate formats (digital, images, PDFs, etc.)

– Must input all into a digital format (e.g. ASCII files)

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Database Structure

• Data are in disparate formats (digital, images, PDFs, etc.)

– Must input all into a digital format (e.g. ASCII files)

• JavaScript Object Notation (JSON): lightweight, hierarchical format for handling all data and metadata for all sites

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JavaScript Object Notation(JSON) File: Site Name

“Location1”:[“BH-name:R1”:[

“velocity profile”:[“depth”:[],“vs”:[]

]],“BH-name”: “R-28”,

“nonlinearTest”: [“strain”:[],“G/Gmax”:[]

]]

]

“Location2”:[“BH-name:GCC”:[

“velocity profile”:[“depth”:[],“vp”:[],“type”: “SASW”

]],“BH-name”: “FWC”,

“SoilSamples”: [“IndexProp”:[],“GrainSizeD”:[],

],],

]

Non-tabular data can easily be stored in nested structure.

A Tool available to create site information data by Albert Kottke.

JSON (JavaScript Object Notation) File

Modified from Shamsher Sadiq 17

Database Structure

• Data are in disparate formats (digital, images, PDFs, etc.)

– Must input all into a digital format (e.g. ASCII files)

• JavaScript Object Notation (JSON): lightweight, hierarchical format for handling all data and metadata for all sites

– UNIFY: program developed by UT and UIUC for JSON output

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Current State of UNIFY

Reference

Name

Data Location

Citation

Bibtex

Notes

Location

Dispersion Curve Data

Geotechnical Data

UNIFY

Velocity Profile Data

Spectral Ratio DataLab Tests Data

Field Tests DataCPT data

SPT data• Geology• Slope gradient• Terrain class• GMX 3rd letter

Hea

der

Modified from Shamsher Sadiq

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Boring Logs

Database Structure

• Data are in disparate formats (digital, images, PDFs, etc.)

– Must input all into a digital format (e.g. ASCII files)

• JavaScript Object Notation (JSON): lightweight, hierarchical format for handling all data and metadata for all sites

– UNIFY: program developed by UT and UIUC for JSON output

• SQL relational database for efficient data querying and transfer

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Database Presentation: Online Interface

• Access database via online platform

• Capabilities will include data download and real-time visualization/plotting of VS profiles and associated metadata

• Eventually: have (select) users upload data community

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https://earthquake.usgs.gov/data/vs30/us/

~2.8 km

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• 1057 in CA to date• 1541 with ROSRINE,

USGS, CGS, DWR data• Potentially: ~2100!

From Shamsher Sadiq

25https://earthquake.usgs.gov/data/vs30/us/

2997 sites in USA and growing!

CA: 1248 ∼2100 (+∼852)PNW: 94 917 (+823)CENA: ???

Future of the VS Profile Database and Alignment with SCEC Research Priorities

APPLICATIONS AND IMPACT

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Applications: SCEC Research Priorities

• Workshop Goals:i. “…foster collaboration between geotechnical engineers, geo-

material scientists, and computational seismologists....”

and

“…bridg[e] the scale between site-specific and region-specific simulations of nonlinear response....”

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Acknowledgements• USGS External Hazards Program Grant No. G17AP00018• Professor Jon Stewart• Alan Yong & Rob Kayen (USGS data)• Bob Nigbor (ROSRINE data)• Chris Wills, Christopher Tran, Jennifer Thornburg (CGS data)• CA Department of Water Resources and DSOD• Dong Youp Kwak• Shamsher Sadiq, Okan Ilhan, Duhee Park, Youssef Hashash• Jonathan Song, Craig Sugiyama, Tristan Whisenant

Sean Ahdi – SCEC Workshop on Nonlinear Shallow Crust Effects – 9/9/2017

Thank you!

Sean Ahdi – SCEC Workshop on Nonlinear Shallow Crust Effects – 9/9/2017