Mandatory Checklist for Sheet Piles Foundation Design.

Designing the foundation for a sheet pile wall involves considerations for stability, soil-structure interaction, and overall structural integrity. Below is a detailed checklist with explanations and examples for the design of a sheet pile foundation:

1. Site Investigation:

Explanation: Conduct a thorough site investigation to understand soil conditions.
Example: Perform soil tests (SPT, CPT) to determine soil properties, groundwater levels, and assess the presence of obstructions.

2. Load Analysis:

Explanation: Analyze and calculate loads acting on the sheet pile wall.
Example: Consider the lateral earth pressure, water pressure, surcharge loads, and any additional loads on the sheet pile wall.

3. Bearing Capacity:

Explanation: Ensure that the soil bearing capacity is sufficient for the applied loads.
Example: If the total lateral load is 120 kN/m and the soil bearing capacity is 200 kN/m², the foundation is considered suitable.

4. Wall Stability:

Explanation: Check and ensure the stability of the sheet pile wall against sliding and overturning.
Example: Conduct a global stability analysis considering factors like sliding resistance, overturning moments, and soil-structure interaction.

5. Sheet Pile Selection:

Explanation: Select appropriate sheet pile types based on soil conditions, water levels, and design requirements.
Example: Choose steel sheet piles for their strength and durability in a corrosive environment.

6. Sheet Pile Wall Configuration:

Explanation: Determine the configuration of the sheet pile wall (cantilever, anchored, or cellular).
Example: Design a cantilever sheet pile wall for a temporary excavation support where lateral loads are relatively small.

7. Sheet Pile Length:

Explanation: Calculate the required length of sheet piles to reach suitable load-bearing strata.
Example: If there’s a layer of dense soil or rock at 8 meters below the ground surface, design sheet piles with lengths exceeding 8 meters.

8. Toe and Heel Details:

Explanation: Address toe and heel details to enhance stability.
Example: Provide a suitable toe extension to resist sliding and a heel extension to enhance overturning stability.

9. Interlocking Mechanism:

Explanation: Specify the interlocking mechanism between sheet piles.
Example: Design sheet piles with interlocks to ensure a continuous and watertight wall.

10. Sheet Pile Wall Alignment:

Explanation: Ensure proper alignment and verticality of the sheet pile wall.
Example: Specify allowable tolerances for verticality to ensure the sheet pile wall performs as intended.

11. Sheet Pile Wall Embedment:

Explanation: Determine the required depth of sheet pile embedment.
Example: If the soil above the bearing stratum is weak, increase the embedment depth to ensure stability.

12. Water Control:

Explanation: Implement measures for water control behind and in front of the sheet pile wall.
Example: Install dewatering systems or use a cut-off wall to control groundwater levels and reduce water pressure.

13. Backfill Material:

Explanation: Specify properties and compaction requirements for backfill material.
Example: Use granular backfill with proper compaction to provide resistance against lateral earth pressure.

14. Corrosion Protection:

Explanation: Consider corrosion protection measures for sheet piles.
Example: Apply a protective coating or use corrosion-resistant materials to enhance the durability of sheet piles.

15. Construction Sequence:

Explanation: Develop a construction sequence that ensures stability during and after construction.
Example: Install sheet piles sequentially, ensuring proper interlocking and alignment to achieve a continuous and stable wall.

16. Quality Control:

Explanation: Implement quality control measures during construction.
Example: Monitor sheet pile installation for proper alignment, penetration, and interlock engagement. Verify backfill compaction.

17. Code Compliance:

Explanation: Ensure compliance with local building codes and standards.
Example: Adhere to relevant codes such as ASTM A690 for steel sheet piles or local geotechnical standards.

18. Professional Engineer Involvement:

Explanation: Engage a qualified geotechnical and structural engineer to oversee the design.
Example: Have licensed engineers review and approve the sheet pile foundation design to ensure it meets safety and code requirements.

19. Record Keeping:

Explanation: Maintain detailed records of the sheet pile foundation design process.
Example: Document all design calculations, soil test results, construction activities, and as-built drawings for future reference and audits.

By following this checklist, engineers can ensure a well-designed sheet pile foundation that effectively resists lateral loads, provides stability, and minimizes potential failure modes.