Sheet Pile Walls

What is a sheet pile wall?

Sheet pile walls are constructed using interlocking steel, vinyl, or composite sheets that are driven into the ground to form a continuous barrier. They are ideal for retaining soil and providing lateral support in challenging environments, particularly where sandy soils and a high water table are present. Sheet piles are often used for:

• Excavation Support
• Permanent or Temporary Retaining Walls
• Waterfront Structures (seawalls, bulkheads, cofferdams)
• Slope Stabilization

Advantages

• Rapid Installation – They can be quickly driven into the ground using vibratory or impact hammers.
• Temporary Shoring -They can serve as a temporary support system for excavation during construction.
• Permanent Wall – They can be integrated into the permanent structure, such as basement walls or foundation systems.
• Water Control – When interlocked correctly, they form a watertight barrier, effectively controlling groundwater in excavation sites.

Limitations

• Installation generally requires vibration or impact hammers which may be disturbing in some environments such as a university or hospital setting. While it is possible to push sheets into the ground, very large equipment would be required.
• Boulders, debris, or abandoned utilities can prevent sheet piles from being driven to the design elevation.

Construction

Vibratory Hammer Installation

• Method: A vibratory hammer is attached to the top of the sheet pile and mounted to a crane or excavator. The hammer generates vibrations, allowing the sheet pile to slide into the soil with minimal resistance.
• Advantages:
  • Fast and efficient for most soil types.
  • Minimal noise compared to impact hammers.
• Best For: Cohesionless soils such as sand and gravel or lower strength silts and clays, as vibrations help displace the soil.

Impact Hammer Installation

• Method: An impact hammer delivers repeated blows to drive the sheet pile into the ground. This technique uses hydraulic or diesel hammers.
• Advantages:
  • Effective in dense or hard soil conditions where vibratory methods may fail.
  • Provides high driving force.
• Best For: Dense soils, clay, or where hard obstructions may be encountered.

Design

• Site Investigation: Analyze soil properties, groundwater levels, and loading conditions through a geotechnical study.
• Earth Pressure Analysis: Calculate lateral earth pressures (active, passive, and surcharge loads) using Rankine or Coulomb theories.
• Wall Geometry: Determine sheet pile depth and alignment to resist overturning, sliding, and deflection.
• Driving Depth: Embed sheet piles into stable soil or bedrock to ensure lateral stability and resistance.
• Support Systems: Incorporate bracing or tiebacks for deeper excavations to reduce bending stresses.
• Structural Analysis: Design sheet piles for shear, bending moment, and deflection limits under anticipated loads.
• Water Control: Use interlocking joints to create watertight barriers in high water table areas.
• Safety Factors: Apply appropriate factors of safety for stability, load-bearing capacity, and long-term performance.

Other Resources

FHWA Circular No. 4 Ground Anchors and Anchored Systems
DFI Anchored Earth Retention Committee