{"id":101184,"date":"2026-04-24T17:09:46","date_gmt":"2026-04-24T17:09:46","guid":{"rendered":"https:\/\/geostru.ai\/en\/products\/liquiter\/"},"modified":"2026-07-08T10:40:25","modified_gmt":"2026-07-08T10:40:25","slug":"liquiter","status":"publish","type":"page","link":"https:\/\/geostru.ai\/fr\/products\/liquiter\/","title":{"rendered":"LiquiTer NX"},"content":{"rendered":"
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LiquiTer NX<\/h1>\n<\/div><\/div>\n\n

Web-based liquefaction analysis of saturated soils under seismic loading \u2014 from in-situ tests (SPT, CPT and shear-wave velocity Vs) to the factor of safety, the Liquefaction Potential Index and post-seismic settlements, layer by layer. Four calculation methods side by side, in the browser, aligned with NTC 2018 and Eurocode 8.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n

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\"LiquiTer<\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n
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What it does<\/h2>\n<\/div><\/div>\n\n

LiquiTer NX takes a soil column from in-situ tests and seismic parameters all the way to a full liquefaction assessment \u2014 the factor of safety against triggering at every depth, the Liquefaction Potential Index and the expected post-seismic settlement, with traceable NTC 2018 and Eurocode 8 reports, entirely in the browser.<\/p>\n<\/div><\/div>\n\n

Input from in-situ tests<\/strong> \u2014 SPT blow counts, CPT\/CPTU tip resistance and shear-wave velocity (Vs) profiles, whichever your investigation provides.<\/p>\n<\/div><\/div>\n\n

Full soil-column model<\/strong> \u2014 layered stratigraphy, groundwater table, fines content and the total and effective vertical stresses computed down the whole profile.<\/p>\n<\/div><\/div>\n\n

Results at every depth<\/strong> \u2014 Cyclic Stress Ratio (CSR), Cyclic Resistance Ratio (CRR), the factor of safety against liquefaction (FSL), the Liquefaction Potential Index (LPI) and post-seismic settlement.<\/p>\n<\/div><\/div>\n\n

Four methods, side by side<\/strong> \u2014 Seed, Tokimatsu, Boulanger-Idriss and Andrus-Stokoe, chosen to match the test data you have.<\/p>\n<\/div><\/div>\n\n

Traceable deliverables<\/strong> \u2014 Word reports and CSV exports; your projects are saved to your own device as .json, not kept on our servers.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n

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The calculation methods<\/h2>\n<\/div><\/div>\n\n

Every method builds on the same seismic demand \u2014 the Cyclic Stress Ratio CSR = 0.65 \u00b7 (a_max\/g) \u00b7 (\u03c3v\/\u03c3'v) \u00b7 r_d \u2014 and differs in how it derives the soil's Cyclic Resistance Ratio (CRR) from your test data.<\/p>\n<\/div><\/div>\n\n

Seed (1971) \u2014 SPT<\/h3>\n<\/div><\/div>\n

Derives CRR from corrected SPT blow counts (N\u2081,\u2086\u2080,cs) with the classic Seed semi-empirical curve \u2014 still the reference method in Italian practice.<\/p>\n<\/div><\/div>\n\n

Tokimatsu (1983) \u2014 SPT<\/h3>\n<\/div><\/div>\n

Separate resistance curves for clean and silty sands driven by grain-size characterisation, useful when the sand classification is well constrained.<\/p>\n<\/div><\/div>\n\n

Boulanger-Idriss (2014) \u2014 CPT\/CPTU<\/h3>\n<\/div><\/div>\n

A continuous CRR profile from normalised cone resistance (qc\u2081N,cs), with fines-content corrections based on the soil-behaviour-type index Ic \u2014 the current international state of the art.<\/p>\n<\/div><\/div>\n\n

Andrus-Stokoe (2000) \u2014 Vs<\/h3>\n<\/div><\/div>\n

CRR from the normalised shear-wave velocity (Vs\u2081,cs), ideal for gravelly or coarse sites where SPT and CPT are hard to drive.<\/p>\n<\/div><\/div>\n\n

Ishihara-Yoshimine (1992) \u2014 settlements<\/h3>\n<\/div><\/div>\n

Post-seismic volumetric settlement of each liquefiable layer as a function of its factor of safety and relative density, summed to the total ground settlement.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n

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Factor of safety, LPI and settlements<\/h2>\n<\/div><\/div>\n\n

From demand and resistance, LiquiTer NX derives the verification at every depth and the whole-profile indices.<\/p>\n<\/div><\/div>\n\n

Factor of safety<\/strong> \u2014 FSL = (CRR \u00b7 MSF \u00b7 K\u03c3) \/ CSR, with the magnitude scaling factor MSF = (Mw\/7.5)^-2.56 correcting for shaking duration and the overburden correction K\u03c3 for confining pressure.<\/p>\n<\/div><\/div>\n\n

Triggering threshold<\/strong> \u2014 a layer is flagged as liquefiable when FSL falls below the limit \u2014 1.25 for NTC 2018, 1.0 for Eurocode 8, or a conservative 1.5 you can set yourself.<\/p>\n<\/div><\/div>\n\n

Liquefaction Potential Index<\/strong> \u2014 the LPI integrates the factor-of-safety deficit over the top 20 m (Iwasaki), turning the whole profile into a single risk figure (0 = negligible, > 15 = high).<\/p>\n<\/div><\/div>\n\n

Post-seismic settlements<\/strong> \u2014 the expected volumetric settlement of each liquefiable layer, summed to the total ground settlement.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n

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How it works<\/h2>\n<\/div><\/div>\n\n

A guided flow takes you from project setup to an exported report in seven steps.<\/p>\n<\/div><\/div>\n\n

1 \u00b7 Project data<\/strong> \u2014 description, operator and site; entering latitude and longitude geolocates the report and helps retrieve the seismic acceleration.<\/p>\n<\/div><\/div>\n\n

2 \u00b7 Water table<\/strong> \u2014 the depth below which soils are saturated and liquefaction can occur; use a conservative value when uncertain.<\/p>\n<\/div><\/div>\n\n

3 \u00b7 Seismic parameters<\/strong> \u2014 code (NTC 2018 or Eurocode 8), ground category (A\u2013E from Vs,30), topographic category (T1\u2013T4), peak ground acceleration ag and moment magnitude Mw.<\/p>\n<\/div><\/div>\n\n

4 \u00b7 Stratigraphy<\/strong> \u2014 each layer with its depths, lithology, unit weight \u03b3, SPT N-value, CPT tip resistance qc, shear-wave velocity Vs and clay content.<\/p>\n<\/div><\/div>\n\n

5 \u00b7 Method & calculation<\/strong> \u2014 pick the method that matches your data (SPT \u2192 Seed\/Tokimatsu, CPT \u2192 Boulanger-Idriss, Vs \u2192 Andrus-Stokoe); the app computes the stresses, r_d, CSR, CRR, FSL and LPI.<\/p>\n<\/div><\/div>\n\n

6 \u00b7 Results<\/strong> \u2014 a depth table (\u03c3v, \u03c3'v, r_d, CSR, CRR, FSL with a colour-coded verdict), the FSL-versus-depth plot and the LPI risk index.<\/p>\n<\/div><\/div>\n\n

7 \u00b7 Export<\/strong> \u2014 a Word report with figures and summary, or a CSV for further analysis.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n

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\"LiquiTer<\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n
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Inputs and outputs<\/h2>\n<\/div><\/div>\n\n

What you enter<\/h3>\n<\/div><\/div>\n

In-situ tests<\/strong> \u2014 SPT, CPT\/CPTU and\/or shear-wave velocity Vs down the profile.<\/p>\n<\/div><\/div>\n\n

Stratigraphy & water<\/strong> \u2014 layer depths, lithology, unit weight \u03b3, clay content and the groundwater table.<\/p>\n<\/div><\/div>\n\n

Seismic action<\/strong> \u2014 code, ground and topographic categories, peak ground acceleration ag and moment magnitude Mw.<\/p>\n<\/div><\/div>\n\n

What you get<\/h3>\n<\/div><\/div>\n

Per-depth verification<\/strong> \u2014 CSR, CRR and the factor of safety FSL at every layer, with the liquefiable layers flagged.<\/p>\n<\/div><\/div>\n\n

Whole-profile indices<\/strong> \u2014 the Liquefaction Potential Index and the expected post-seismic settlement.<\/p>\n<\/div><\/div>\n\n

Charts<\/strong> \u2014 the FSL-versus-depth profile plotted against the chosen threshold.<\/p>\n<\/div><\/div>\n\n

Deliverables<\/strong> \u2014 a Word report and a CSV export, with the project saved to your device as .json.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n

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Who it's for<\/h2>\n<\/div><\/div>\n\n

Geologists \u00b7 Geotechnical engineers \u00b7 Seismic specialists \u00b7 Consulting firms. LiquiTer NX is for anyone who assesses liquefaction susceptibility and triggering \u2014 for building and infrastructure foundations, seismic-zone construction and site-characterisation studies \u2014 and wants a single web environment that goes from in-situ tests to a fully verified, code-compliant assessment.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n

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Why it's different<\/h2>\n<\/div><\/div>\n\n

Runs directly in the browser \u2014 no installation, works on Windows, Mac and Linux, always up to date.<\/p>\n<\/div><\/div>\n\n

Four triggering methods (SPT, CPT and Vs) plus post-seismic settlements, side by side.<\/p>\n<\/div><\/div>\n\n

The full NTC 2018 and Eurocode 8 chain \u2014 CSR, CRR, FSL, LPI and settlements \u2014 traceable end to end.<\/p>\n<\/div><\/div>\n\n

FSL-versus-depth and LPI outputs that make the result immediate to read.<\/p>\n<\/div><\/div>\n\n

Your projects are saved to your own device as .json \u2014 calculations run encrypted server-side, and nothing is shared.<\/p>\n<\/div><\/div>\n\n

Word and CSV deliverables ready for the report.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n

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Frequently asked questions<\/h2>\n<\/div><\/div>\n\n

Can I use LiquiTer NX on clays?<\/strong>
No. Liquefaction concerns saturated sands and silty sands; clays with more than about 35% of particles finer than 5 \u00b5m are automatically excluded.<\/p>\n<\/div><\/div>\n\n

How much does the result change between Seed and Boulanger-Idriss?<\/strong>
In typical clean or silty sands the factor of safety differs by about 10\u201320%; Boulanger-Idriss tends to be more conservative in silty sands.<\/p>\n<\/div><\/div>\n\n

Why do some layers show FSL = 99?<\/strong>
That marks a non-liquefiable layer: above the water table, more than about 35% clay, deeper than 20 m, or with SPT blow counts too high to liquefy.<\/p>\n<\/div><\/div>\n\n

Where do I get ag and Mw for my site?<\/strong>
ag (NTC 2018) comes from the seismic-parameters service with your coordinates and return period; Mw is the maximum expected magnitude of the INGV seismogenic zone.<\/p>\n<\/div><\/div>\n\n

Does it work on a slope?<\/strong>
LiquiTer NX assumes horizontal ground; on a slope the static shear stress modifies the resistance, so the assessment no longer applies directly.<\/p>\n<\/div><\/div>\n\n

Is there a free plan?<\/strong>
Yes. The Free plan includes access, the full calculation and CSV export; a subscription adds the Word report, AI import, multi-site batch and priority support.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n

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Ready to start with LiquiTer NX?<\/h2>\n<\/div><\/div>\n\n

Choose your plan and start using LiquiTer NX today. Runs in the browser, always up to date, no installation required.<\/p>\n<\/div><\/div>\n\n\n\n\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":0,"featured_media":101182,"parent":101181,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_ai_seo_pilot_schema_type":"auto","footnotes":""},"class_list":["post-101184","page","type-page","status-publish","has-post-thumbnail","hentry"],"_links":{"self":[{"href":"https:\/\/geostru.ai\/fr\/wp-json\/wp\/v2\/pages\/101184","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/geostru.ai\/fr\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/geostru.ai\/fr\/wp-json\/wp\/v2\/types\/page"}],"replies":[{"embeddable":true,"href":"https:\/\/geostru.ai\/fr\/wp-json\/wp\/v2\/comments?post=101184"}],"version-history":[{"count":2,"href":"https:\/\/geostru.ai\/fr\/wp-json\/wp\/v2\/pages\/101184\/revisions"}],"predecessor-version":[{"id":102099,"href":"https:\/\/geostru.ai\/fr\/wp-json\/wp\/v2\/pages\/101184\/revisions\/102099"}],"up":[{"embeddable":true,"href":"https:\/\/geostru.ai\/fr\/wp-json\/wp\/v2\/pages\/101181"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/geostru.ai\/fr\/wp-json\/wp\/v2\/media\/101182"}],"wp:attachment":[{"href":"https:\/\/geostru.ai\/fr\/wp-json\/wp\/v2\/media?parent=101184"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}