Civil Engineering Structures: Tunnels, Bridges, Ports, and More

Workshop Building Summary

Buildings are structures created throughout history to provide shelter.

Tunnels

Tunnels are complex and costly constructions, including walkways, highways, waterways, and rail tunnels.

Tunnel Guidance

Excavation occurs simultaneously from both ends, requiring precise alignment using modern laser systems or traditional methods like theodolites.

Digging, Blasting, and Securing

Tunnels are dug using compressed air drills on vehicles. Explosives break rock, conveyor belts remove debris, and concrete linings support the tunnel. Boring machines with rotating heads are also used.

Tunnel Challenges

Risks include flooding, landslides, computer malfunctions, and dust from explosions.

Bridges

Bridges span depressions or obstacles like water, supporting roads, railways, and pipelines.

Types of Bridges

Arch

Arch bridges distribute weight to supporting pillars and adjacent land, allowing longer spans.

Cantilever

Cantilever bridges divide weight symmetrically, supported by a central point, often used in drawbridges.

Braces

Braces bridges are attached near the center of their beams, like the Normandy (2,200m) and Forth (1890) bridges.

Armature

Armature bridges have two lateral beams, covering long distances and supporting transit between or above fasteners.

Stayed (En Arpha)

Stayed bridges use braces to support the structure with retention on one or two strong lateral beams.

Hanging Bridges

Hanging bridges support weight on vertical supports anchored to the ground, with towers supporting cables.

Mobile or High Bridges

Mobile bridges, like London's Tower Bridge, move to allow ship passage by lifting, rotating, or sliding.

Ports

Ports must resist tides and vary in size.

Sections include armed ports, dry docks, liquid bulk, containers, copper refining, shipping, and dry bulk solids.

Protections

• Castled structures dissipate wave energy.
• Artificial rocks or concrete (tetrapods or idols) are used.
• Moles, concrete walls, reflect waves.

(Lights can be considered part of a port.)

Airports

Airports have civil and building works, including passenger terminals and runways designed for aircraft loads.

Railways

Railways consist of steel bars on wooden bases to increase surface area.

Earthquakes: Generation, Action, and Effects

Earthquakes originate in the lithosphere, where tectonic plates move and collide.

Plate Motion

• Divergent: Plates move apart.
• Transforming: Plates slide past each other.
• Convergent: Plates collide, forming subduction zones.

Volcanic earthquakes are caused by eruptions.

• Hypocenter: The earthquake's origin point below the surface.
• Epicenter: The point directly above the hypocenter on the surface.

Magnitude (Richter scale) measures energy released.

Waves

• Primary (P-waves): Sound-like surface waves.
• Secondary (S-waves): Transverse waves moving across the ground.
• Tertiary: Combination of P and S waves.

Mercalli scale measures surface movement intensity (1-12).

Tsunami or Tidal Wave

Tsunamis are caused by seafloor changes from large underwater earthquakes.