This is the CPT door. Give it depth, qc and
fs for the whole sounding; the server derives Ic, picks the
critical layer, and screens it against the documented field case histories in
the Next Generation Liquefaction (NGL) database.
Case record
NGL field case histories
You paste
depth, qc, fs (u2 optional)
Deliverable
PDF and CSV, HMAC-signed
When to use this door
Use it when you hold a full CPT trace and want the critical layer chosen
from the data rather than by hand. Server-side selection is auditable and
you can override the depth window before running.
When to use the other door
Use the manual door when you hold layer values rather than a trace: SPT
blow counts, shear wave velocity, or a single already-chosen CPT layer.
Both doors run the same screening and return the same deliverable.
Liquefaction screening against NGL case histories. GeoLiquefy LLC is independent and not affiliated with the NGL project.
FAQ
CPT Profile Input
1
Paste CPT Profile Data
Paste up to four columns from your CPT software: depth, qc (tip resistance), the
friction column (fs or Rf), and an optional u2 (pore pressure) column. Comma- or
tab-separated, with a header row, one reading per line. Set the units for each
column below: we preselect what we detect from your header, but your selection is
what we use. The critical layer you select is matched against the Next Generation
Liquefaction (NGL) database, more than 8,600 documented field case histories.
Minimum 10 rows of data (plus the header row).
2
Profile Visualization & Critical Layer
Critical Layer (Auto-selected)
Why this layer?
The critical layer is the 1 m depth window (between 0.5 m and 15 m)
with the lowest average cone resistance (qc): the weakest sand-like
zone, which controls liquefaction susceptibility. Fine-grained
readings (friction ratio above 5%, or Ic above 2.6) are excluded so
the window stays within the clean-sand framework the screening curves
are calibrated for. Adjust the depth range below if your judgment
differs.