caa a22 4500 465808808 CHVBK 20180323112110.0 cr unu---uuuuu 170327e19901001xx s 000 0 eng 10.1007/BF02592620 doi (NATIONALLICENCE)springer-10.1007/BF02592620 Quality assessment of large armourstone using an acoustic velocity analysis method [Elektronische Daten] [M. Niese, F. Van Eijk, G. Laan, P. Verhoef] Détermination de la qualité de gros enrochements par la méthode d'analyse de la vitesse du son Large armourstone blocks are used to protect coastal construction against current and wave forces. Ideally such blocks should be durable and stay intact during engineering lifetime. The quality of these large blocks is, among other factors, influenced by the occurrence of internal disturbances, such as fissures. If the blocks fracture, spall or abrade during engineering lifetime a construction may be significantly weakened and finally failure may take place. In this investigation attention is focussed on the prediction of spalling and fracturing of rock blocks due to pre-existing fissures. The quality of the blocks was assessed by measuring the velocity of acoustic waves propagating through the rock. The acoustic measurements were done with commercially available simple equipment. For an appreciation of the results of the velocity measurements, the blocks were dropped from a specified height in droptests. In the laboratory the effect of normal pressure on open discontinuities to the acoustic velocity was investigated. The data obtained from the acoustic measurements were handled according to a simple method based on the cumulative distribution of normalized velocities. An important result of the investigation is the development of a general classification system for armourstone based on acoustic measurements: The "I-value” is obtained by the data handling method and gives information about the distribution of the acoustic velocities of a rock I-value Class Description < 1.25 I good 1.25-2.00 II moderate > 2.00 III bad block. A value of one means that no significant disturbances are present in the block tested. International Assocaition of Engineering eology, 1990 Niese M. Faculty of Mining and Petroleum Engineering, Section of Engineering Geology, Delft University of Technology, P. O. Box 5028, 2600 GA, Delft, The Netherlands aut Van Eijk F. Faculty of Mining and Petroleum Engineering, Section of Engineering Geology, Delft University of Technology, P. O. Box 5028, 2600 GA, Delft, The Netherlands aut Laan G. Road and Hydraulic Engineering Division, Rijkswaterstaat, P. O. Box 5044, 2600 GA, Delft, The Netherlands aut Verhoef P. Faculty of Mining and Petroleum Engineering, Section of Engineering Geology, Delft University of Technology, P. O. Box 5028, 2600 GA, Delft, The Netherlands aut Bulletin of the International Association of Engineering Geology - Bulletin de l'Association Internationale de Géologie de l'Ingénieur Springer-Verlag 42/1(1990-10-01), 55-65 0074-1612 42:1<55 1990 42 10064 https://doi.org/10.1007/BF02592620 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02592620 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Niese M. Faculty of Mining and Petroleum Engineering, Section of Engineering Geology, Delft University of Technology, P. O. Box 5028, 2600 GA, Delft, The Netherlands aut NATIONALLICENCE 700 1- Van Eijk F. Faculty of Mining and Petroleum Engineering, Section of Engineering Geology, Delft University of Technology, P. O. Box 5028, 2600 GA, Delft, The Netherlands aut NATIONALLICENCE 700 1- Laan G. Road and Hydraulic Engineering Division, Rijkswaterstaat, P. O. Box 5044, 2600 GA, Delft, The Netherlands aut NATIONALLICENCE 700 1- Verhoef P. Faculty of Mining and Petroleum Engineering, Section of Engineering Geology, Delft University of Technology, P. O. Box 5028, 2600 GA, Delft, The Netherlands aut NATIONALLICENCE 773 0- Bulletin of the International Association of Engineering Geology - Bulletin de l'Association Internationale de Géologie de l'Ingénieur Springer-Verlag 42/1(1990-10-01), 55-65 0074-1612 42:1<55 1990 42 10064 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer