Tunnel Engineering and Rock Mechanics

The design and construction of underground passages for transportation, utilities, or mining.

The study of how rock masses behave under stress.

How much force a piece of rock can withstand without breaking (in a lab).

The natural pressures already acting on the rock before tunneling.

How water affects tunnel stability and excavation.

How broken or intact the rock is, shown by the drill core samples.

The distance between natural fractures in the rock.

The length of rock fractures.

The direction of rock fractures relative to the tunnel.

A method to evaluate the quality and performance of rock to help design tunnel construction.

A system for assessing the quality of rock to assist with tunnel design and support.

Rock Quality Designation (percentage of intact rock in core samples) in the Q-system.

Ways to maintain tunnel stability, based on the Q-system.

Steel bars anchored in rock to provide reinforcement.

Longer, flexible steel cables used for deeper tunnel stabilization.

Plates and straps that distribute tunnel forces and prevent rock movement.

Steel mesh used to contain loose rock in tunnels.

Sprayed concrete for immediate tunnel stabilization.

Indicates the support level needed based on tunnel use and safety.

Requires high tunnel stability (e.g., nuclear facilities).

Requires less tunnel stability (e.g., temporary mine tunnels).

Bolt length (L) = 2 + 0.15 x Span

Shotcrete separates from the rock surface.

Shotcrete layer slides off under pressure.

Shotcrete with fibers for extra strength and reduced cracking.

Long, flexible steel cables used for deeper tunnel stabilization.

Plates and straps to distribute forces and prevent rock movement at the tunnel surface.

Steel mesh used to contain loose rocks within tunnels.

Sprayed concrete for immediate tunnel stabilization.

Indicates the level of support needed in a tunnel based on tunnel usage and safety.

Requires high stability for a tunnel (e.g., nuclear facilities).

Requires less stability for a tunnel (temporary mine tunnels).

Bolt length (L) = 2 + 0.15 x Span

Shotcrete separating from the rock surface.

The shotcrete layer sliding off under pressure.

Shotcrete with added fibers for increased strength and flexibility.

The process of designing and building underground passages (tunnels) for various purposes like transport, utilities, or mining.

The study of how rock behaves when exposed to forces (stress).

The resistance of a rock sample to breaking, tested in a lab.

The natural forces acting on rock before tunneling.

How water affects tunnel stability and excavation.

How unbroken the rock is, evaluated from core samples.

The distance between fractures in the rock.

The length of a rock fracture.

Method for evaluating rock quality to help design tunnel projects.

A rock mass evaluation system used to determine suitable tunnel support.

Rock Quality Designation: Percentage of intact rock measured from drill core samples.

A formula for evaluating rock mass quality using values like RQD, Jn, Jr, Ja, Jw, and SRF.

Structures used to maintain tunnel stability and prevent collapses.

Steel bars that anchor into rock to provide support.

Structures used to support unstable ground, often in excavations, using hydraulic braces or sheet piles.

Sprayed concrete used to immediately stabilize rock surfaces, especially in tunnels.

Reinforcements for tunnels, including rock bolts and mesh, to keep the walls stable.

Ways to support foundations, either driven piles (deep) or bored piles (for urban areas).

Pre-stressed concrete is made stronger and more durable by introducing tension during the construction process.

Structures used to prevent soil from collapsing, often featuring drainage and reinforcement.

Beams combining the strength of steel and concrete, increasing overall load capacity.

Structures that prevent soil from collapsing or sliding.

Retaining walls that rely on their own weight to resist soil pressure.

Retaining walls that use a rigid base to resist bending.

Walls using layers of soil reinforced with materials for extra strength.

Retaining walls made of rock-filled cages.

Layers in retaining walls that prevent water buildup to avoid pressure.

Temporary structures used to stabilize excavations.

Steel beams driven into the ground, braced with lagging.

Interlocking panels used for temporary soil retention.

Steel and concrete beams combined for efficiency.

Components that connect steel and concrete in composite beams.

Structures vibrate at specific frequencies when dynamic loads occur.

Long-span bridges that use cables suspended between towers.

Bridges with cables extending directly to the bridge towers.

How long structural elements can withstand fire.