Underground Excavation Design - 2021 entry

Effective design is critical for the stability and creation of a safe working environment for underground excavations. The module commences with a critical review of input data required for design of underground excavations (building on previous knowledge obtained in ‘Excavation and Geomechanics’ or equivalent). The model investigates factors influencing the design of underground excavations, including both discontinuity and stress-controlled instability. The module is not recommended for interdisciplinary pathways.

The module provides specialist analysis and design skills associated with underground mining and related industries. The module provides problem-solving, data-handling and evaluation skills. The module also provides an opportunity for students to develop an awareness of risk assessment applied to underground excavation design.

Where appropriate, case history information is used to emphasize important aspects associated with data variability and its influence on design.

Computer-based design exercises are used to emphasize and consolidate key aspects of how stress redistribution and discontinuity characteristics affect excavation stability and choice of appropriate stabilization methods.

On successful completion of this module you should be able to:

The module commences with a review of critical input parameters for design of underground excavations, emphasising the differences between discontinuity controlled behaviour and rock mass material controlled instability. Excavation results in a redistribution of the in-situ stress field, induced displacements within the rock mass in response to excavation and perturbation of the groundwater.  

Data visualisation is a key part of the module, using design-based software for enhanced learning and awareness of both stress-controlled and discontinuity-related failure of underground excavation.

The module covers factors influencing underground excavation design. Key subject areas studied include:

- Design methodology (including empirical, analytical and observational design);

- Use and application of rock mass classification for estimation of stabilization requirements;

- Overview of underground mining methods and excavation dimensioning; empirical hangingwall design, including use Laubscher MRMR and Stability Graph Method;

- Stereographic analysis of roof and sidewall instability; underground wedge analysis (UnWedge)

- Stabilisation techniques/methods, including reinforcement and support, and a review of underground excavation monitoring and instrumentation;

- Kirsch equations, shape factors, non-circular stress redistribution, effects of discontinuities on excavation stability;

- Design of excavations in sedimentary rock;

- Rock mass-support interaction, excavation stabilization techniques and their interaction with ground deformation;

- Pillar design, including estimation of pillar stress and pillar strength;

- Rock engineering systems approach;

- Large cavern design.

The module also includes a review and use of commercially available software for design purposes, and an awareness of deterministic versus probabilistic design and risk analysis applied to excavation design.

If a student is referred or deferred, the failed / non-completed component(s) will be re-assessed at the same weighting as the original assessment.

Basic reading:

ELE: http://vle.exeter.ac.uk/

Web based and Electronic Resources:

https://www.rocscience.com/learning/hoek-s-corner – Hoek’s Corner

Other Resources:

Reading list for this module: