What are the best practices for installing a deep foundation?

1 Site investigation

Before installing a deep foundation, you need to conduct a thorough site investigation to assess the soil and groundwater conditions, the presence of any obstructions or contaminants, and the potential environmental impacts. A site investigation typically involves drilling boreholes, taking soil samples, performing in-situ tests, and analyzing the data. The site investigation will help you determine the type, size, length, and spacing of the deep foundation elements, as well as the installation method and equipment.

2 Design and specification

Based on the site investigation results and the structural requirements, you need to design and specify the deep foundation system that meets the load-bearing capacity, settlement, and durability criteria. You also need to consider the geotechnical, structural, and construction aspects of the design, such as soil-structure interaction, load transfer mechanism, pile-soil-pile interaction, axial and lateral resistance, buckling, corrosion, and seismic effects. You should use appropriate codes, standards, and guidelines to ensure the reliability and safety of the design and specification.

3 Installation method and equipment

Depending on the type and size of the deep foundation elements, you need to choose the most suitable installation method and equipment that can achieve the design objectives and minimize the site disturbance. Some of the common installation methods are driven, bored, or drilled, and each has its own advantages and disadvantages. For example, driven piles are fast and economical, but they may cause noise and vibration problems. Bored or drilled piles are quieter and more flexible, but they may require casing or fluid support to prevent collapse. You should also select the appropriate equipment, such as hammers, augers, drills, or rigs, that can handle the soil conditions and the depth of the installation.

5 Testing and monitoring

After the installation is completed, you need to test and monitor the performance of the deep foundation system to verify its load-bearing capacity, settlement, and durability. Testing and monitoring may involve static or dynamic load tests, strain gauges, settlement plates, inclinometers, and corrosion sensors. Testing and monitoring will help you evaluate the adequacy and efficiency of the deep foundation system, identify any defects or problems, and provide feedback for future design and installation improvements.

6 Maintenance and repair

Finally, you need to maintain and repair the deep foundation system to ensure its long-term serviceability and safety. Maintenance and repair may include periodic inspection, cleaning, protection, and reinforcement of the deep foundation elements, as well as remediation of any damages or failures. You should also follow the relevant codes, standards, and guidelines for maintenance and repair, and use qualified and experienced personnel and equipment.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?