Title: Mass Production of Highly Toleranced Precast Concrete Tunnel Segments

Author(s): John A. Bickley

Publication: Concrete International

Volume: 1

Issue: 4

Appears on pages(s): 39-46

Keywords: inspection; pre-cast concrete; production methods; quality control; tolerence (machanic); tunnel linings;

DOI:

Date: 4/1/1979

Abstract:
Over a period of 20 months, precast concrete tunnel segments were produced by Pre-Con Murray at their Brampton Plant. These segments were made to a very small tolerance and used to form rings for a section of the Toronto Yonge Street Subway Tunnel lining. Approximately 66,000 units were produced. The problems encountered in the production and in-spection of the tunnel lining segments occurred mainly in the first few months of production. These were mainly eliminated, and in looking at the analysis it is seen that high degree of quality control was maintained over a period of some 20 months.