18-Geol-A5 Rock Mechanics
Worked solutions to 6 past sittings (2013–2017), 30 questions. Pick a sitting, or start from a topic below.
Topics across the sittings
Topics that come up in more than one sitting, taken from the headings of our worked solutions. A topic counts once per sitting.
- Rock mass classification systems (2 sittings): May 2016 Q3 · December 2015 Q1
Questions by sitting
December 2017
- Question 1: Design strategy for uncertainty in a bedded/jointed highway tunnel
- Question 2: Empirical rock mass classification systems
- Question 3: Limestone pillar design — RMR, Hoek–Brown strength, tributary-area FoS
- Question 4: Mohr–Coulomb parameters from triaxial compression data
- Question 5: RQD, RMR and excavation/support design from core-box and point-load data
May 2016
- Question 1: Fault reactivation and critical pore pressure
- Question 2: Open-pit wedge factor-of-safety derivation
- Question 3: Rock mass classification systems — systems, strengths and limitations
- Question 4: Instability mechanisms, tunnel damage zone, failure criteria and pillar design
- Question 5: Kirsch boundary stress around a deep circular tunnel
December 2015
- Question 1: Rock mass classification systems
- Question 2: Pillar RMR, Hoek-Brown strength and factor of safety
- Question 3: Water/seismic effects on pit walls; ground support functions
- Question 4: Plane failure with a water-filled tension crack
- Question 5: RQD, RMR and stand-up time for a tunnel
December 2014
- Question 1: Joint Shear Strength — Patton Bilinear Criterion and Pore-Pressure-Induced Failure
- Question 2: Pre-Construction and Construction-Phase Strategy for a Subway Tunnel Under Uncertainty
- Question 3: Combined Toppling (Block A) and Sliding (Block B) — Verification-Case Statics
- Question 4: Elastic Constant and Mohr-Coulomb Parameters from a Zero-Axial-Strain Triaxial Path
- Question 5: Single-Plane-of-Weakness Theory — Two Orthogonal Fracture Sets
December 2013
- Question 1: RQD, RMR and Unsupported Stand-up Time for a Tunnel in Jointed Rock
- Question 2: Mohr-Coulomb Parameters from Triaxial Compression Data
- Question 3: Principal Stress Orientation from a Vertical Shear Fracture
- Question 4: Tributary-Area Pillar Stress and Elastic Deformation in a Potash Mine
- Question 5: Circular Drift Stability, Support Pressure and Concrete Liner Design
Undated paper
- Question 1: Kirsch boundary stress — single tunnel and a second, parallel tunnel
- Question 2: Support pressure for the Excavation Disturbed Zone (EDZ)
- Question 3: RMR and Q classification for two tunnel scenarios
- Question 4: Mohr–Coulomb design of a circular drift and its concrete liner
- Question 5: Water/vibration effects on pit-wall stability, and ground-support functions