DESIGN RECOMMENDATIONS FOR CONCRETE TUNNEL LININGS--VOLUME II: SUMMARY OF RESEARCH AND PROPOSED RECOMMENDATIONS

The report presents design recommendations for concrete tunnel linings for transportation tunnels. The recommendations developed as a result of in-depth analysis and model testing of the behavior of concrete tunnel linings. The research addressed problem areas in current design practice, and the results have provided insight into the areas of uncertainty that have led designers to gross overconservatism in tunnel lining design. The recommended procedures take into account ultimate strength behavior of reinforced and unreinforced concrete linings and provide sufficient latitude for designers to exercise judgement gained thourgh experience and allow the flexibility required by site-specific conditions. Details of the suggested approach are based on procedures that have been accepted for years in the design of above-ground structures, with appropriate modifications to capitalize on the benefits of ground/structure interaction.