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It is well known that the use of equipment from different manufacturers, and diverse measuring systems or types of penetrometer, affect the results obtained from CPT. As far as the types of penetrometer are concerned, cone geometry and the kind of measuring method prove to be equally crucial. For exactly the same soil, the values of the qc and fs measured with an electric and mechanical penetrometer, can be different. It is also indicated that owing to the applied interpretation method, correlations relevant for an electric cone are inappro-priate for a mechanical cone. The most common CPT interpretations relate to the standard electric cone. The coefficients given by several studies could be used to convert values obtained in CPT with an electric penetrom-eter cone into the values appropriate for a mechanical cone, but those coefficients seem too general. This is the reason why research to determine the correlation between the results of CPT using different types of penetrometer cone was conducted. In-situ tests were carried out on Lublin loess, where the loess silt bed reaches a thickness of 10-15 metres. There were 15 comparative CPT in the distance 1.0 – 2.0 m between tests carried out with an electric cone and a mechanical cone. The same penetration device was used in both types of test. Obtained prob-ing profiles were processed in order to eliminate measurement error caused by the distance between test locations. As a result, the proportional coefficient between tests with two types of penetrometer cone, suitable for Lublin loess, was determined.
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