Construction Machinery and Deep Foundation Techniques

Tower Cranes: Lifting and Horizontal Movement

Tower cranes facilitate lifting, turning, and horizontal translation of loads. Key components include:

• Base: Mounted on rails, gantries, or embedded footings.
• Tower or Mast: The vertical climbing structure.
• Turntable: Allows for rotation.
• Jib (Arrow): The horizontal arm.
• Ballast: Provides stability.

Technical Characteristics: Maximum and minimum outreach, maximum height, crane power, and load capacity (which varies based on outreach). Key metrics include maximum load, minimum range, and tip load.

Erecting Cranes

These cranes feature high-speed assembly and lower load capacities. They spin at the base, occupy more floor space, and can be towed or moved independently.

Hydraulic Cranes

Used for installing tower cranes, positioning equipment, prefabricated assembly, and internal load placement. Telescopic truck cranes consist of a chassis, diesel engine, suspension stabilizers, and a superstructure capable of hoisting, rotation, and boom manipulation.

Deep Foundations

Deep foundations consist of piles and pile caps, categorized by diameter: Micropiles (<20cm), Normal (20-60cm), and Large (80-150cm).

• Continuous Flight Auger (CFA): Soil is extracted while concrete is injected simultaneously, resulting in low vibration.
• Driven Piles: Metal or concrete piles are driven into the ground. This method is effective for compaction but generates noise and vibration.
• Bored Piles: Concrete is injected through a tube to form a bulb at the head.
• Steel H-Piles: Driven by hydraulic jacks, though this process is notably noisy.

Slurry Walls

These are deep, reinforced concrete walls constructed before excavation using thixotropic sludge (bentonite) to maintain stability. Process: Site layout, guide wall construction, batch excavation, reinforcement introduction, joint placement, concrete pumping via Tremie tube, coronation beam construction, interior bracing with anchors, and final stabilization.

Sheet Piling (Tablaestacados)

Interlocking piles create a waterproof enclosure for excavation. Types:

• Tongue and Groove: Used for deep excavations or high water tables.
• Tabs: Used for shallow depths without a water table.

WellPoint Systems

Used for temporary groundwater depletion via vacuum pumping. Components:

• Drainage Nozzles: Galvanized steel pipes with 1m filters.
• Junction Sleeves: Connect nozzles to the driving line.
• Collector Header (GC): Flexible tubing connecting sleeves to the vacuum pump.
• Vacuum Pump (BdV): Creates suction to absorb and circulate water.
• Jacking Pump: Uses pressure water to sink the spears.

Underpinning Foundations

Techniques to improve foundation performance by extending the surface area or reaching more resistant soil layers. Systems:

• Extended Footings: Increasing the base area.
• Micropiling: Structural reinforcement.
• Jet Grouting: High-pressure mortar injection creates large-diameter columns by mixing mortar with the soil.