The development of digital radiographic techniques has opened up new non-destructive testing possibilities in the study of the physical and structural characteristics of natural materials. Since these techniques allow a quick and accurate definition of density, stratigraphy, structure and state of disturbance prior to laboratory testing, they are most appropriately useful in the case of very sensitive materials. Digital radiographs and computerized tomographies have been carried out on cores of soft marine clays of present--day and very recent sedimentation, taken at different depths in the submerged part of the Tiber River delta. On the basis of these analyses it was possible to: 1) obtain a detailed definition of the stratigraphy `of the cores, identifying their sedimentary structures and lithology and/ or structural variations which, owing to the apparent homogeneity of the materials, cannot be perceived with the naked eye; 2) obtain density logs which are more accurate than those measured by means of laboratory tests; 3) verify that density values from computerized tomography correlate with laboratory values. A number of tests were carried out to analyse the sensitivity of the method with respect to the experimental parameters and to work out the best testing procedure
Lo sviluppo di apparecchiature radiografiche digitali apre nuove possibilità di analisi non distruttiva per la caratterizzazione fisica e strutturale dei materiali naturali. Queste tecniche sono particolarmente utili nel caso di materiali molto sensibili dei quali è necessario definire in modo accurato e veloce densità, stratigrafia, struttura e disturbi, prima che vengano sottoposti a prove di laboratorio. Sono state eseguite analisi radiografiche digitali e tomografie assiali computerizzate su carote di argille marine soffici di sedimentazione attuale e sub-attuale prelevate a diverse profondità sulla parte sommersa della conoide deltizia del Fiume Tevere. Lo studio ha permesso di: 1) definire in dettaglio la stratigrafia delle carote, evidenziando anche quelle strutture sedimentarie (variazioni litologiche e/o strutturali) che, a causa dell'omogeneità apparente dei materiali, non sono ben percepibili con un'analisi visiva; 2) ottenere dei log di densità dei materiali con un'accuratezza maggiore rispetto alle procedure di laboratorio; 3) verificare che i valori di densità misurati tramite TAC sono ben correlati con le misure di laboratorio. Sono state eseguite numerose prove per analizzare la sensibilità del metodo rispetto ai diversi parametri sperimentali e per definire la migliore procedura di analisi.
Tomografia a raggi X (TAC) e radiografie digitali di carote di sedimenti marini argillosi soffici
Chiocci FL;Tommasi P;
1995
Abstract
The development of digital radiographic techniques has opened up new non-destructive testing possibilities in the study of the physical and structural characteristics of natural materials. Since these techniques allow a quick and accurate definition of density, stratigraphy, structure and state of disturbance prior to laboratory testing, they are most appropriately useful in the case of very sensitive materials. Digital radiographs and computerized tomographies have been carried out on cores of soft marine clays of present--day and very recent sedimentation, taken at different depths in the submerged part of the Tiber River delta. On the basis of these analyses it was possible to: 1) obtain a detailed definition of the stratigraphy `of the cores, identifying their sedimentary structures and lithology and/ or structural variations which, owing to the apparent homogeneity of the materials, cannot be perceived with the naked eye; 2) obtain density logs which are more accurate than those measured by means of laboratory tests; 3) verify that density values from computerized tomography correlate with laboratory values. A number of tests were carried out to analyse the sensitivity of the method with respect to the experimental parameters and to work out the best testing procedureI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.