TECHNIQUES AND EQUIPMENT USING THE SURVEYOR'S LEVEL FOR ACCURATE MEASUREMENT OF BUILDING MOVEMENT

Equipment and techniques are described in sufficient detail for those who may wish to make settlement observations on buildings. It is important that settlement observations be made both during construction and for a period of years thereafter. Information that must be recorded in addition to levelling records is listed. Levelling stations should be purpose-made units built into the structure. The requirements of such stations are outlined. A levelling station is described (and illustrated) which consists of a stainless steel socket (65 mm long and 22 mm diameter), which is set in a hole in the structure, and a removable levelling plug of about the same dimensions on which the base of a staff is held when levels are taken. The installation in prepared holes, casting in concrete and extension of levelling stations are detailed. The requirements for datums are discussed. A 6m datum described which is constructed from an inner datum rod made from 10 mm bore galvanized tube sorrounded by a guard tube of 25 mm bore, together with specially manufactured end pieces. Details are given of the installation. A precision level was used together with an invar staff at 10 mm intervals. The procedure is described. The method of presentation of results is illustrated by observations taken over 13 years. The datum judged to be most reliable should be called the main datum (DI) and its level designated as 0.00 mm, as necessary to avoid negative levels, 1 000.00 mm etc. The frequency of levelling will be dictated by the specific case.

Media Info

  • Features: Figures; References;
  • Pagination: p. 13-21

Subject/Index Terms

Filing Info

  • Accession Number: 00263196
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 12 1974 12:00AM