Screen site-specific liquefaction hazard with Boulanger & Idriss (2014) CPT-based triggering, computed against the site and drawn against the published reference boundary curves that share its axis, Idriss & Boulanger (2008) and Moss et al. (2006). It draws on 8,634 in-situ test records from the Next Generation Liquefaction (NGL) database.
Input CPT or SPT measurements, shear wave velocity, fines content, depth, groundwater table, and seismic loading (PGA, Mw). The tool accepts the full parameter set used in practice.
The engine searches 8,634 in-situ test records from the NGL database and returns the most geotechnically similar sites, ranked by similarity score. Retrieve the top 1, 3, 5, or 10 matches.
Each result set includes an AI-drafted engineering assessment memo: CSR, CRR, and, when fines content is supplied, the factor of safety, all from Boulanger & Idriss (2014), drawn against the published reference curves that share the CPT axis, plus field remarks from the original reconnaissance data. The engine computes every number and the memo quotes them; the AI drafts and explains, and never does the arithmetic.
The engine computes a single, deterministic triggering procedure, Boulanger & Idriss (2014), against every site. Two other published boundary curves share its CPT axis and are drawn alongside it for visual comparison, not computed into the result. A third, Cetin et al. (2004), is SPT-based and is returned on its own axis.
Semi-empirical CPT- and SPT-based liquefaction triggering procedure, computed deterministically against the site. The only triggering computation in the engine.
Boulanger, R.W. & Idriss, I.M. (2014), “CPT and SPT Based Liquefaction Triggering Procedures,” Report UCD/CGM-14/01, UC Davis.
An SPT-based boundary curve evaluated from the paper's own closed form (eq. 20) at PL=15%, Mw=7.5, σ′v=1 atm, FC=0%. Its abscissa is clean-sand-equivalent SPT N1,60, so it is returned on its own SPT axis rather than drawn on the CPT plot.
Cited as Cetin et al. (2004).
A CPT-based triggering boundary curve from the published correlation, plotted for comparison only.
Moss, R.E.S., Seed, R.B., Kayen, R.E., Stewart, J.P., Der Kiureghian, A. & Cetin, K.O. (2006), J. Geotech. Geoenviron. Eng., 132(8).
An earlier CPT- and SPT-based boundary curve from the same authors, plotted for comparison only.
Idriss, I.M. & Boulanger, R.W. (2008), Soil Liquefaction During Earthquakes, EERI Monograph MNO-12.
The published curves do not always agree. Drawing Moss and Idriss & Boulanger alongside the computed Boulanger & Idriss (2014) result, with Cetin on its own SPT axis, shows where the published boundary curves diverge: information for the engineer's judgment, not another computed output. Read the full methodology →
The tool accepts the complete set of parameters used in geotechnical liquefaction assessment.
qc, fs, Fr, Ic, u2
N60, Fines Content, D50, PI, Unit Weight
Vs, Vs30
Depth, GWT Depth, PGA, Mw
Send site parameters, get ranked matches and an AI-drafted assessment back as JSON.
POST /api/similar
Authorization: Bearer <clerk-session-token>
Content-Type: application/json
{
"params": {
"qc": 4.2, // Cone tip resistance (MPa)
"fs": 0.05, // Sleeve friction (MPa)
"fines_content": 18, // Fines content (%), needed for a factor of safety
"depth": 6.5, // Sample depth (m)
"gwt_depth": 1.5, // Groundwater table depth (m)
"pga": 0.32, // Peak ground acceleration (g)
"mw": 6.2 // Moment magnitude
},
"top_n": 10
}
Authenticated with a Clerk session token, the same sign-in the web app uses. Issued API
keys are not available yet. GET /api/cases/by-location is open and needs no
token.
Billed monthly. Cancel anytime.
$216 billed annually.
Tailored to your organization.
The Liquefaction Hazard Engine computes Boulanger & Idriss (2014) CPT-based triggering, drawn against the published reference boundary curves that share its CPT axis, Moss et al. (2006) and Idriss & Boulanger (2008), with Cetin et al. (2004) returned on its own SPT axis. It draws on 8,634 in-situ test records from the NGL database, 354 sites across 31 earthquakes (Brandenberg et al., 2020). Robb Moss, author of Moss et al. (2006), a CPT-based triggering model plotted as a reference curve in the engine, serves on GeoLiquefy's advisory board.
Pro is $30/month billed monthly, or $18/month ($216/year) billed annually. Enterprise pricing is custom, for high-volume usage, priority support, and multi-seat access.
Yes. Submit a JSON payload of site parameters (CPT, SPT, shear wave velocity, site and seismic inputs) to /api/similar and receive ranked matches from the NGL database with an AI-drafted assessment in a single response, for GIS and portfolio risk workflows.
Geotechnical consultants, who use it from site investigation to signed report, and reinsurers, cat modelers, and risk analytics teams, who screen liquefaction as a portfolio- level damage multiplier via the API.
The AI computes nothing. Boulanger & Idriss (2014) computes CSR and CRR, and the engine divides them for the factor of safety at the engineer's input point; the AI is handed those finished numbers to quote and drafts the engineering-readable memo and explanation around them.