NUMERICAL MODELLING OF TUNNELS IN BLOCK-IN-MATRIX FORMATIONS
Abstract
<p>This paper presents an automated workflow linking a voxel-based block-in-matrix (BiM) ground model to PLAXIS 2D through its Python HTTP API, focusing on finite element (FE) simulation of tunnel excavation in such heterogeneous rock. Building on prior borehole-constrained ground model and conditional random field (CRF) matrix-variability studies, the paper details the material models, excavation sequence and script logic used to transfer voxelized cross-sections, each containing thousands of block and matrix polygons, into PLAXIS 2D via batched API requests. Both block and matrix are represented with the Mohr-Coulomb elastic-perfectly plastic criterion; blocks are described with constant values of geomechanical parameters while matrix parameters vary spatially. Excavation is simulated by the convergence-confinement method in ten deconfinement stages. Results show generally reduced but scattered radial displacements relative to a homogeneous deterministic model. </p>