Discussed in this paper are domestic and foreign concepts for the design of plain concrete tunnel lining. Comparisons are made in terms of the respective design capacity assumed by the concepts. A newconcept, tailored to u.s. Tunnel design practice, which builds on an advanced approach to defining the capacity of plain concrete tunnel lining, is developed. The first concept is the standard approach incorporated in the deutsches institute fur normung (din) building code (din 1045). This concept is built on strength design criteria similar to those considered in american concrete institute (aci) code 318, strength design. The applicability of this design concept to unreinforced concrete tunnel lining has been proven extensively during the last decade. Partial cracking of the concrete, a characteristic of strength design, is restricted by the code to the extent that stability and safety requirements are observed. The second concept discussed is incorporated in the aci code 318.1, building code requirements for structural plain concrete. In contrast to din 1045, the aci code is based on working stress provisions, which thus precludes cracking of the concrete. A comparison of the permissible lining forcesof the two concepts is presented. A new combined design concept, based on discussions of aci 318.1 and din 1045, is developed. This concept is specifically tailored to the design of underground lining and incorporates u.s. Design practices. Aci building codes 318 and 318.1 are used for reference. This paper appeared in transportation research record no. 1150, tunneling. For covering abstract see irrd no 818446.
Abstract