This paper describes a comprehensive, non-contact survey method, thermography, for assessing the condition of tunnels. Weak thermal currents caused by the normal differences in temperatures between the air in the tunnel and the bedrock form the basis of the method. These currents are affected by the physical properties of the tunnel lining, including voids and poor backfilling in the crown, or dampness in or behind the crown. The raw measured data is processed and refined to form the basis for a computer assisted engineering analysis. Taking parameters such as the thickness of the tunnel lining, the type of bedrock and natural fissures into account a series of data sheets is produced. At the same time as the thermographic survey, linear surveys can be made to examine deformations in the tunnel lining. Details are given of the equipment needed and method of operation. The software involved is in two main sections - survey software controlling data acquisition and storage and analytical software controlling analysis and graphic output. Details are given of the types of graphic output available. A survey vehicle is described which can travel on road or rail and carry thermographic, linear survey and profile survey equipment. An on-line data-transfer system has been developed for the wide variety of monitoring tasks required during surveys, maintenance or construction. Automatic profile-measuring equipment such as the Amberg Profiler 2000 provides fast and accurate information on the tunnel profile. A project diskette is produced and up to 30 different design profiles can be stored. Profiles can be recomputed and intervention is possible by means of a hand held computer.

  • Availability:
  • Corporate Authors:

    Mining Journal Limited

    60 Worship Street
    London EC2A 2HD,   England 
  • Authors:
    • -
  • Publication Date: 1989-12


  • English

Media Info

  • Pagination: 4 p.
  • Serial:
    • Volume: 2
    • Issue Number: 6
    • ISSN: 0956-8700

Subject/Index Terms

Filing Info

  • Accession Number: 00606859
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Mar 31 1991 12:00AM