ABSTRACT
This work presents an evaluation of the geomechanical behavior of a bio-constructed limestone layer formed by coral sedimentation near the surface on a Caribbean coastal plain. These rocks are denominated Caliza and Caliche. Caliza overlaps Caliche. Since Caliza is a less deformable rock than Caliche, the displacements observed on the surface were negligible when compared to those occurring in in-depth excavations. The study was based on convergence and settlement reference pin measurements arranged in cross sections along a 1km shallow tunnel in a very dense urban area of Santo Domingo – Dominican Republic. Tunnel overburden varies from 4 to 20m. The measurements were evaluated considering several aspects of a partial excavation, the excavation front positioning and the GSI values of each excavation front.
