A model test and numerical investigation on the shear deformation patterns of deep wall-soil-tunnel interaction

In congested urban areas, tunnel excavations have become necessary due to a lack of space. In many cases, such excavations are needed in areas adjacent to existing loaded piles. Therefore, a careful assessment of the wall-soil-tunnel interaction is required. These circumstances are relatively new, however, and only limited information is currently available. The complicated soil behaviour, particularly for the shear failure pattern between the wall and tunnel observed in both physical tests and numerical analyses, has not been clearly identified by other researchers. The authors have conducted laboratory model tests on an idealized granular medium using close-range photogrammetric techniques to measure detailed displacement patterns. The results have been compared with those from numerical analyses. This paper presents shear failure patterns for a number of geometries and shows good agreement between the physical tests and the finite element analyses.