Earthworks and Demolition: Key Construction Processes

Earthworks and Land Modification

Excavation (Dismantling)

Excavation lowers the terrain to reach the required level or flat plane. It always involves digging below the planned leveling plane ($\text{dl}$). Workers need to exclude rocky terrain requiring explosives.

Embankment

Embankment construction raises the ground level to a scheduled height. It consists of several layers:

• A) Foundation: Area below the ground surface.
• B) Nucleus: The main mass of the embankment.
• C) Coronación (Crowning): The final 50 cm layer.

Soil Mechanics Concepts

Proctor Density

In earth embankments, soil is compacted to obtain maximum density at the optimum moisture content.

Drainage

A drain is an open pit excavation around the perimeter, situated $\text{x}$ below the earth-moving plane.

If the excavation exceeds $\text{ms}$, the ditch or well is considered significant.

Excavation Types

• Trench: Maximum width of 2 m and maximum depth of 7 m.
• Well: Excavations of small area for footings, inspection chambers, etc.
• Deep excavations (TB) can reach great depths to accommodate deep foundations and stilts.

Seizures and Slopes

Seizures: The limit defined by the intersection of the slope and the embankment or natural ground clearance.

Natural Slopes: Relate the natural slope of the land to a horizontal plane.

Volume Changes

Swell (Sponges): This is the increase in volume experienced by the soil when it is loosened or removed.

Compaction: Decreases the volume of the land due to compaction of the embankment and watering, which reduces the swell. The final result depends on the harshness of the terrain, the type of soil, and the compaction effort.

Item 5: Demolition Procedures

Definitions

Demolition: Destroying a building or part thereof, resulting in the disappearance of the structure.

Deriba (Debris/Dismantling): Dismantling a part of the building structure, often salvaging materials.

Types of Demolition

Depending on the size, demolition can be:

• Partial Demolition: Only a part of the building is destroyed.
• Total Demolition: The entire structure is destroyed.

Methods for Demolition

1. Demolition by Elements

Elements are demolished in the reverse order of their construction, starting from the roof down. Tools: Electric hammer, jackhammer, chisel, angle grinder (Flexo).

2. Demolition by Collapse

Uses explosives, heavy machinery, or global demolition techniques, regardless of the original construction order.

3. Mixed Demolition

Both systems (elemental demolition and collapse) are used within the same building.