Paul S. Design Recommendations for Concrete Tunnel Linings..1983 torrent

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This report describes model tests and analytical studies that were performed to augment background information based on experience, interviews with design engineers, and review of the literature to propose design recommendations for concrete tunnel linings. Tests of model arches that represent underground stations and circular linings that represent continuous tunnels in rock-like media are described. Ten arches, 6 ft (1.8 m) diameter, were tested to investigate modes of failure and determine the effects of lining thickness, medium stiffness, lining stiffness, lining reinforcement, shear between the lining, and medium and active load shape. Tests are also described of five circular linings, 1.0 in. (25 mm) thick and 44 in. (1120 mm) diameter, in which the effects of lining reinforcement, medium stiffness, and joints in the lining are investigated. A computer based analysis is described that will simulate a concrete lining and include the nonlinear behavior due to material properties of the concrete and reinforcement and cracking of the concrete. In the analysis, the nonlinearity due to deformations can also be included. The medium around the lining can be represented by radial and tangential springs or by continuum elements, and in the latter case, a special interface element between the lining and medium may be used. This analysis was used to simulate the model tests to verify the program and the various input parameters, and then to investigate the various parameters that have a major influence on lining behavior and lining-medium interaction