this report relates to a research programme being undertaken jointly by the water research centre (wrc) and the transport and road research laboratory (trrl) and covers a section of the initial work being carried out by william f rees limited under a trrl sponsored contract to study methods of inspection, maintenance, and renovation of sewers. the work defines various categories of defects commonly encountered during closed circuit television (cctv) survey work and gives a typical example from each category. the accuracy of a sample of existing cctv survey reports is then investigated by a comparison of the new survey reports - prepared following through re-examination of video tape recordings - with the original documents. this procedure is facilitated by use of a coding system, developed to permit precise definition of defects. the prospective use of such a coding system as a basis for computer storage and manipulation of survey data is discussed and preliminary work to determine the suitability of the proposed system for such application is described. results obtained indicate that the data contained in cctv survey reports provides a reasonable assessment of a sewers' conditions, depending on the type of survey executed.(a)

Want to know more about this project?