Material Flow Reconciliation: Risk Management for Pressurized Face Tunneling

摘要

Overexcavation during pressurized face tunneling is a risk factor with respect to unplanned surface deformation and damage to existing installations above the tunnel. Risk management typically includes surface and subsurface deformation monitoring of critical areas identified during planning and design. However, continuously reconciling material flows during the mining process is a risk management tool that allows recognizing and correcting causal trends before effects are observed. This paper describes the reconciliation methods for different TBM types, provides project examples from Seattle area tunnels, and discusses risk management implementation approaches involving the owner, designer, contractor, and third party asset holders.