Bearing capacity of cohesive-frictional soils over a shallow tunnel

摘要

The ultimate bearing capacity and the failure mechanism of cohesive-frictional soils with the inclusionrnof shallow tunnels have been theoretically and numerically investigated assuming plane strain conditions.rnAt present, no generally accepted design or analysis method is available to evaluate the ultimate bearingrncapacity of cohesive-frictional soils with shallow tunnel inclusions. In this study a continuous loading is appliedrnto the ground surface, and both smooth and rough interface conditions between the loading and soils arernmodelled. For a series of tunnel geometries, shapes and material properties, rigorous lower and upper boundrnsolutions for the ultimate bearing capacity of the considered soil mass are obtained by applying recently developedrnnumerical limit analysis techniques. For practical suitability the results are presented in the form ofrndimensionless stability charts. As an additional check and also a handy practical means, upper bound rigidrnblock mechanisms for shallow tunnels have been developed.