Blog
What Is a CPT? The Cone Penetration Test Explained
What is a CPT (cone penetration test)? The measurement, the parameters qc, fs, Rf and u2, how to read the CPT plot and what soundings are used for.
Open a GEF File and Convert It to Excel, CSV or AGS
Open a GEF CPT file without special software and convert it to Excel, CSV, JSON or AGS4. Free in the browser, without uploading your data anywhere.
Identifying Soil Types from a CPT: The Robertson Classification
How do you derive peat, clay and sand from cone resistance and friction ratio? The Robertson classification (SBT) and qc rules of thumb for Dutch soils.
Digitizing an Old CPT Sounding to GEF: From Scan to Usable File
Step-by-step guide to converting a scanned CPT sounding (PDF or image) into a GEF file with cone resistance per depth, ready for your design software.
The GEF File Explained: How a CPT Sounding in GEF Format Is Built Up
What's inside a GEF CPT file? Explanation of the headers, columns, penetration length, the NAP reference level and the most common import errors.
Cone Resistance (qc): Why This Parameter Governs Your Pile Design
Cone resistance qc is the key input for pile bearing capacity under NEN 9997-1. What does qc tell you about the soil and how accurately do you need it?
Reusing Old CPT Soundings: When Is It Justified and Where to Find Them?
Existing CPTs from DINOloket or municipal archives can save new site investigation. When is reuse justified and how do you make the data usable?