Subhead 20.0: Pile Work

Subhead 20.0: Pile Work

This section covers the specifications for installing pile foundations in construction projects. Pile foundations are deep foundations used to transfer heavy loads from structures to stable soil layers deep underground. Here is a detailed breakdown of the content typically covered under this subhead:

20.1 General Specifications

• Scope: Installation and testing of various types of piles in building and infrastructure projects.
• Materials: Specifications for materials used in pile work, including concrete, steel, and timber.
• Workmanship: Standards for workmanship to ensure the durability and load-bearing capacity of piles.

20.2 Types of Piles

• Driven Piles: Piles driven into the ground using hammers or vibratory drivers.
• Bored Piles: Piles constructed by boring holes into the ground and filling them with concrete.
• Sheet Piles: Interlocking steel or concrete piles used to form continuous barriers for retaining walls and cofferdams.

20.3 Driven Piles

• Materials: Specifications for precast concrete piles, steel piles, and timber piles.
• Driving Equipment: Use of drop hammers, diesel hammers, and vibratory drivers.
• Driving Procedures: Methods for driving piles to the required depth and load-bearing capacity.
• Pile Caps and Cut-offs: Construction of pile caps to distribute loads and cutting off pile heads to the required level.

20.4 Bored Piles

• Materials: Specifications for concrete and reinforcement used in bored piles.
• Boring Equipment: Use of rotary drilling rigs, augers, and casing.
• Boring Procedures: Methods for boring holes, placing reinforcement, and pouring concrete.
• Temporary Casing: Use of temporary casing to support boreholes and prevent collapse.

20.5 Testing of Piles

• Static Load Testing: Applying gradual load to a pile and measuring its settlement.
• Dynamic Load Testing: Using a hammer blow to apply load and measure pile response.
• Integrity Testing: Methods like sonic logging and low strain integrity testing to check for defects in piles.

20.6 Pile Caps and Ground Beams

• Construction: Procedures for constructing pile caps and connecting piles with ground beams.
• Reinforcement: Placement of reinforcement to ensure load distribution and structural integrity.
• Concreting: Pouring and curing concrete for pile caps and ground beams.

Examples:

1. Installation of Driven Precast Concrete Piles:

   • Preparation: Transport precast concrete piles to the site and position them for driving.
   • Driving: Use a drop hammer to drive the piles into the ground to the required depth and resistance.
   • Cut-off: Cut off the pile heads at the required level and prepare for pile cap construction.
   • Pile Caps: Construct pile caps to distribute structural loads to the piles.

2. Construction of Bored Cast-in-Place Concrete Piles:

   • Boring: Use a rotary drilling rig to bore holes to the required depth.
   • Temporary Casing: Insert temporary casing to support the borehole and prevent collapse.
   • Reinforcement: Place reinforcement cages into the borehole.
   • Concreting: Pour concrete into the borehole, ensuring proper compaction and curing.
   • Removal of Casing: Gradually remove the temporary casing as the concrete is poured.

3. Dynamic Load Testing of Piles:

   • Preparation: Position a drop hammer or a hydraulic hammer above the pile head.
   • Testing: Apply a series of hammer blows to the pile and measure the pile's response using sensors.
   • Analysis: Analyze the data to determine the load-bearing capacity and integrity of the pile.

4. Construction of Pile Caps and Ground Beams:

   • Excavation: Excavate the area around the pile heads to the required depth for the pile cap.
   • Reinforcement: Place reinforcement cages for the pile cap and ground beams.
   • Formwork: Set up formwork to contain the concrete.
   • Concreting: Pour and compact concrete, ensuring proper curing for the pile cap and ground beams.

Thu Jun 6, 2024