Both driven piles and bored piles are methods of constructing reinforced concrete piles capable of bearing significant loads to support the structure. Each type has its own advantages and disadvantages, making it suitable for different projects based on structure, technical specifications, and construction approach.
The Importance of Pile Foundations
Pile foundations are crucial in construction due to the following benefits:
- Minimal settlement, reducing the risk of structural deformation.
- Deep foundation placement prevents significant settlement effects on surrounding structures.
- Flexible construction process, allowing adjustments in depth, diameter, and other parameters to match soil conditions.
- Ideal for weak, narrow, and easily subsiding soil foundations.
- Cost-effective solution.
- Fast construction progress with ensured quality.
Advantages of Driven Piles (Precast Concrete Pile Driving Method)
- Minimal noise pollution.
- Lower cost compared to bored piles.
- Suitable for small to medium-sized projects, such as residential houses, single-story buildings, factories, townhouses, and villas.
- Quick construction time, typically 2-4 days.
- Pre-manufactured materials, saving time and costs.
- High load-bearing capacity.
- No vibrations, preventing damage to neighboring structures.
- Better quality control, as each pile segment is tested under pressure to determine its final load capacity.
Advantages of Bored Piles (Drilled Shaft Pile Method)
- Higher load-bearing capacity, with greater flexibility in diameter and depth.
- Pile dimensions can be customized to suit project needs.
- No impact or vibration, making it ideal for urban environments and structures close to existing buildings.
- Can penetrate thick sand layers and hard soil formations.
- Direct geotechnical inspection allows for a more accurate soil assessment.
- If soil conditions and equipment allow, bored piles can be expanded with a base diameter ranging from 60 cm to 250 cm and a depth of up to 100 meters, increasing load capacity.
Disadvantages of Driven Piles
- Not suitable for extremely high-load projects or soft soil areas requiring excessive depth.
- Extensive site preparation needed, including clearing obstacles and leveling.
- Requires weight loads (counterweights) to be transported and stockpiled 1-2 days before installation.
- Limited depth capabilities.
- Dependent on transportation conditions, such as clear roads, minimal sharp turns, and adequate clearance for power lines.
Disadvantages of Bored Piles
- Generates large amounts of slurry and mud during drilling.
- Complex and costly quality control process.
- Reduced side friction between pile and soil due to drilling.
- Difficult to rectify defects, sometimes requiring demolition and reinstallation.
- Requires advanced construction technology with skilled labor.
- Higher cost compared to driven or driven-cast-in-place piles.
When to Use Driven Piles or Bored Piles?
Based on the advantages, disadvantages, and site conditions, the following recommendations can be made:
Use Driven Piles When:
- The project requires more load-bearing support than shallow foundations but not as much as bored piles (as determined by structural engineers).
- Used primarily for residential buildings with moderate loads.
- The neighboring structures are sturdy and not at risk of vibration damage.
- The soil conditions are stable.
- Ample space and accessible roads allow easy transport and pile installation.
Use Bored Piles When:
- Space is limited, and the project is surrounded by closely built structures.
- Used for renovation or building extensions where existing foundations cannot be removed.
- The soil is semi-hard, preventing driven piles from reaching necessary depths, while bored piles can be drilled deeper.
- Ideal for high-rise buildings (above five stories) in areas with thick weak soil layers.
- Not recommended in open construction sites without nearby structures, as driven piles would be a more cost-effective alternative.
- Can be executed using both mechanical and manual drilling, making it adaptable to narrow alleyways and small construction sites.
