FAQ

Screw piling, also known as screw pile foundation or helical piling, is a type of deep foundation that uses screw-in steel helical shafts to anchor structures to the ground. This method involves driving a pile with one or more helical plates into the soil. The helical plates act like screw threads, allowing the pile to be screwed into the ground with minimal soil displacement.

Key Features of Screw Piling:

1. Installation: Screw piles are installed using hydraulic motors that apply rotational torque to the pile, causing it to advance into the ground.

2. Load Capacity: The helical plates on the piles provide resistance against both compressive and tensile loads, making them suitable for various applications. 

3. Versatility: They can be used in different soil conditions, including loose and waterlogged soils, which makes them highly versatile.

4. Speed and Efficiency: Installation is typically quicker and more efficient than traditional concrete foundations, with less noise and vibration.

5. Environmental Impact: The installation process causes minimal disturbance to the soil and surrounding environment.

Applications:

• Residential and commercial buildings
• Retaining walls
• Bridges and walkways
• Temporary structures
• Underpinning existing foundations

Advantages:

• Fast installation with immediate load-bearing capacity 
• Can be installed in various weather conditions
• Minimal excavation required
• Easily removable and reusable
• Less environmental impact compared to traditional piling methods

Screw piling is particularly beneficial in areas where traditional foundation methods are challenging or where rapid installation is necessary.

Screw piles are a versatile foundation solution suitable for a wide range of applications. Here are some situations where screw piles are particularly advantageous:

1. Rapid Construction Timelines

• Immediate Load-Bearing Capacity: Screw piles can bear loads immediately after installation, making them ideal for projects with tight deadlines.

2. Urban and Sensitive Environments

• Minimal Noise and Vibration: The installation process generates less noise and vibration compared to traditional piling methods, which is beneficial in urban areas or near sensitive structures.

3. Poor Soil Conditions

• Versatility in Soil Types: Screw piles perform well in various soil conditions, including loose, soft, or waterlogged soils where traditional foundations might struggle.

4. Environmentally Sensitive Areas

• Minimal Soil Displacement: The installation process causes minimal disturbance to the soil and surrounding environment, making screw piles suitable for environmentally sensitive areas.

5. Remote or Hard-to-Access Locations

• Ease of Transport and Installation: Screw piles can be transported and installed with relatively simple equipment, making them suitable for remote locations with limited access.

6. Retrofitting and Underpinning

• Structural Support: Screw piles can be used to reinforce or underpin existing structures, providing additional support without significant excavation.

7. Coastal and Marine Applications

• Waterlogged and Soft Soils: Screw piles are effective in coastal and marine environments where traditional piles may be difficult to install.

8. Cost-Effective Solutions

• Lower Installation Costs: The installation process is generally quicker and requires less heavy equipment than traditional foundations, reducing overall costs.

9. Projects Requiring Flexibility

• Adjustable Load Capacity: Screw piles can be installed to different depths and with varying helical plate sizes to match specific load requirements.

What are some examples of Screw Pile applications

• Residential and Commercial Buildings: Foundations for houses, apartments, and commercial buildings.
• Bridges and Walkways: Foundations for pedestrian bridges, walkways, and overpasses.
• Underpinning: Reinforcing and stabilizing existing foundations.

The depth to which screw piles can be installed depends on various factors, including the soil conditions, load requirements, and the design of the screw pile itself. Here are some general guidelines and considerations:

Typical Depths

Residential and Light Commercial Projects: Screw piles for these types of projects typically range from 3 to 8 meters deep.

Heavy Commercial and Industrial Projects: For more substantial structures, screw piles can be installed to depths of 8 to 18 meters or more.

Factors Affecting Depth

1. Soil Conditions:

• Soft or Loose Soils: May require deeper installation to reach stable, load- bearing strata.
• Dense or Rocky Soils: May achieve adequate load-bearing capacity at shallower depths.

2. Load Requirements: Higher load requirements may necessitate deeper installation to distribute the load over a larger area or to reach more stable soil layers.

3. Pile Design:

• Helical Plates: The size and spacing of the helical plates can influence the depth needed to achieve the desired load capacity.
• Shaft Diameter and Material: Thicker or more robust shafts may support deeper installations.

4. Environmental Factors:

• Frost Depth: In colder climates, screw piles may need to be installed below the frost line to prevent heaving and ensure stability.
• Water Table: High water tables may require deeper piles to avoid buoyancy issues.

Depth Verification

Testing and Monitoring: During installation, the depth and load capacity of screw piles are often verified through testing and monitoring, such as torque measurements and load tests, to ensure they meet the design specifications.

Conclusion

Screw piles can be installed to various depths depending on project requirements and site conditions. Typical depths range from 3 to 18 meters, but deeper installations are possible with the right design and equipment. Proper assessment and engineering are crucial to determine the optimal depth for each specific project.

Obligation free quotation

• Evaluation of structural engineering plans and geotechnical report
•  Quotation provided for screw piling including bearer brackets/plates made to order if required

Design and Engineering

• Site Assessments: Evaluation of soil conditions, load requirements, and environmental factors to design appropriate screw pile solutions.
• Custom Design: Engineering design of screw piles and helical foundations tailored to specific project needs.
• Reg. 126: Certificate of compliance for Design

Installation

• Screw Pile Installation: Professional installation of screw piles using specialized equipment. This includes precise placement and alignment to ensure structural integrity.
• Depth and Load Testing: Testing and monitoring during installation to confirm that the screw piles meet load-bearing requirements and are installed to the correct depth.
• Welding: bracket to top of piles to support bearer if required

Foundation Solutions

• Residential Foundations: Installation of screw piles for residential buildings, including houses and apartment complexes.
• Commercial Foundations: Foundations for commercial properties, including office buildings, retail spaces, and industrial facilities.
• Retaining Walls: Support and stabilization of retaining walls to prevent soil erosion and maintain structural stability.
• Boardwalks, Jetties and bridge abutments: Using custom designed brackets welded to top of pile to support bearer

Underpinning and Reinforcement

• Existing Foundation Support: Strengthening and stabilizing existing foundations through underpinning methods that use screw piles to provide additional support.
• Structural Reinforcement: Enhancing the load-bearing capacity of existing structures to address settlement or other issues.

Specialized Applications

• Coastal and Marine Foundations: Installation of screw piles in coastal or marine environments where traditional foundation methods may be challenging.
• Temporary Foundations: Providing screw pile solutions for temporary structures, such as event spaces or construction supports.

You can email your plans and soil report for an obligation-free quote to info@allstatesp.com.au, or call their Melbourne office on 03 9773 5251. You can also leave a message via their contact page.