DETECTION OF UNDERGROUND CAVITIES BY MEANS OF SEISMIC REFLECTION - RS 370

DETECTION DE CAVITES SOUTERRAINES PAR SISMIQUE REFLEXION RS 370

THIS SUMMARY OUTLINES THE RESULTS OBTAINED BY THE GENERAL DELEGATION TO SCIENTIFIC AND TECHNICAL RESEARCH NO 74-7-1405. A STUDY IS MADE OF THE POSSIBILITY OF APPLYING REFLECTED WAVES AT A SHALLOW DEPTH. ALL TESTS HAVE SHOWN THAT THE ABNORMAL SOUND CAUSED BY A CAVITY IS ONLY THE SOUND SIGNAL REFLECTED FROM THE ROOF. THIS SIGNAL HAS A LARGE AMPLITUDE BECAUSE OF THE HIGH ACOUSTIC CONTRAST AND IS GENERALLY OF A LOW FREQUENCY CHARACTER. VARIOUS STUDIES HAVE SHOWN THE IMPORTANCE OF THE VERTICAL COMPONENT AND OF THE SEISMIC SOURCE. IT IS CONCLUDED THAT ONLY THE DIFFERENTIAL METHOD SEEMS ADAPTED TO THE LOCALISATION OF UNDERGROUND CAVITIES. THE DISTANCE BETWEEN THE SEISMIC SOURCE AND THE SENSOR MUST BE SHORT AND THE SEISMIC SOURCE MUST HAVE A FREQUENCY SPECTRUM AS WIDE AS POSSIBLE, ESPECIALLY IN THE VICINITY OF HIGH FREQUENCIES AND MUST BE STRICTLY ACCURATE. MAGNETIC RECORDING ENSURES SEVERAL REPLAYS FOR VARIOUS POSSIBLE TREATMENTS. IT SEEMS INDISPENSABLE TO HAVE A HIGHLY MOBILE EXTRA-LIGHT EQUIPMENT WHICH IS VERY FLEXIBLE IN USE.

• Authors:
  • Horn, R
  • PERAGALLO, I

Language

• French

Media Info

• Pagination: 49-51
• Serial:
  • RESUME DES PRINCIPAUX RESULTATS SCIENTIFIQUES ET TECHNIQUES DU SERVICE GEOLOGIQUE NATIONAL POUR 1976
  • Publisher: EDITIONS DU BRGM

Subject/Index Terms

• TRT Terms: Reflectivity; Seismicity; Surveying
• Uncontrolled Terms: Cavities; Site investigation; Subterranean
• ITRD Terms: 5738: Cavity; 5926: Reflectivity; 5731: Seismic; 5722: Site investigation; 4372: Subterranean
• Subject Areas: I41: General Soil Surveys;

Filing Info

• Accession Number: 01295348
• Record Type: Publication
• Source Agency: Institut Francais des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)
• Files: ITRD
• Created Date: Nov 21 2010 4:59AM