Code of practice for design and construction of port and harbour structures, Part 3: Sheet pile walls

IS 9527 Part 3: Introduction and Scope - Key Points

• Scope:
  Design and construction criteria for sheet pile walls in port and harbour structures, used as permanent or temporary earth retaining walls.

• Definitions & Symbols (Clause 3.1):

  • ( Ap ): Anchor pull force
  • ( D ): Depth of embedment of sheet pile
  • ( F_s ): Factor of safety
  • ( H ): Height of retained earth
  • ( L ): Horizontal distance from anchor to sheet pile wall edge
  • ( x ): Depth of point of inflexion below dredge level
  • ( \gamma ), ( \gamma' ), ( \gamma_{sat} ), ( \gamma_w ): Unit weights (bulk, submerged, saturated, water)
  • ( \delta ): Angle of wall friction
  • ( \phi ): Angle of internal friction

• Depth of Point of Inflexion (x) (Clause C-1.2 & Table 1):
  Used in fixed-earth support method for anchored sheet pile walls:

• Design Reference:
  Interpolate (x) from Table 1 for given (H) and (\phi) (see Fig. 8 in the code).

Summary Diagram of Parameters

graph LR
    H[Height of Retained Earth (H)]
    x[Depth of Point of Inflexion (x)]
    D[Embedment Depth (D)]
    L[Anchor Distance (L)]
    Ap[Anchor Pull (Ap)]
    H --> x
    x --> D
    L --> Ap

Note: Final values should be rounded per IS:2-1960 for compliance.

IS 9527 Part 3 — Key Definitions & Tables

1. Letter Symbols (Clause 3.1)

2. Depth of Point of Inflexion (Clause 1.2, Table 1)

• x is interpolated from this table, where H = height of retained earth.

3. Reduced Anchor Pull (Clause 5.1)

[ A_p = \left[(P_p - P_A) - (P'_p - P'_A)\right] \times F_s \times L ]

Where:

• (A_p) = allowable anchor pull
• (P_p, P'_p) = passive earth pressures
• (P_A, P'_A) = active earth pressures
• (L) = length of deadman
• (F_s) = factor of safety

Summary Diagram: Sheet Pile Wall Parameters

graph TD
    A[Retained Earth Height (H)] --> B[Point of Inflexion (x)]
    B --> C[Depth below Dredge Level]
    D[Anchor Pull (Ap)] --> E[Deadman Length (L)]
    F[Embedment Depth (D)] --> G[Sheet Pile Wall]
    H[Unit Weights (γ, γ', γ_sat,

IS 9527 Part 3: Types of Sheet Pile Walls – Key Points

1. Types of Sheet Pile Walls (Clause 4.1)

• Timber
• Reinforced Concrete
• Prestressed Concrete
• Steel (Clause 9.3 focuses here)

2. Steel Sheet Piles (Clause 9.3)

• Steel sheet piles are preferred for high strength, durability, and ease of installation.
• Typical sections: Z-type, U-type, or straight web profiles.

3. Design of Cantilever Sheet Pile Walls (Clause 8.1 & Appendix A)

• Cantilever walls: unsupported at the top, fixed at the bottom.
• Design involves calculating bending moments and shear forces due to soil and water pressure.

4. Key Formulas for Cantilever Sheet Pile Walls (Appendix A)

• Bending Moment, M at depth ( z ):

[ M(z) = \int_z^{D} (p(z') \times (z' - z)) dz' ]

where ( p(z') ) = lateral earth pressure at depth ( z' ), ( D ) = embedment depth.

• Shear Force, V at depth ( z ):

[ V(z) = \int_z^{D} p(z') dz' ]

• Embedment Depth, D is calculated to balance moments from active soil pressure and passive soil resistance.

5. Typical Earth Pressure Distribution (for design)

• Active earth pressure, ( p_a = K_a \gamma z )
• Passive earth pressure, ( p_p = K_p \gamma (D - z) )

where:

• ( K_a ), ( K_p ) = active and passive earth pressure coefficients
• ( \gamma ) = unit weight of soil
• ( z ) = depth below ground surface

Summary Table: Sheet Pile Wall Types

IS 9527 Part 3: Materials for Steel Sheet Piles

Key Specifications (Clauses 4.1.4 & 9.3)

• Steel Grade: As per IS 2314-1963.
• Copper Content: 0.2% to 0.35% Cu for corrosion resistance in seawater.
• Usage: Steel sheet piles preferred for:
  • Driving through hard strata.
  • Temporary works (reusable).
  • Situations requiring watertightness.

Material Properties (Typical for IS 2314 Steel)

Design Considerations (from IS 9527 Part 3 & related codes)

• Steel sheet piles must resist bending and soil pressures.
• Section modulus and moment of inertia based on pile shape.
• Corrosion allowance must be considered for permanent works.

Typical Formulas

• Bending Stress:
  [ f_b = \frac{M}{Z} ]
  where ( M ) = bending moment, ( Z ) = section modulus.

• Corrosion Allowance:
  Add thickness based on exposure (typically 1-3 mm for seawater).

flowchart TD
    A[Steel Sheet Piles] --> B[IS 2314 Steel]
    B --> C{Copper Content 0.2-0.35%}
    A --> D[Applications]
    D --> E[Permanent: Hard strata, watertight]
    D --> F[Temporary: Reusable]
    A --> G[Design]
    G --> H[Bending Stress: f_b = M/Z]
    G --> I[Corrosion Allowance]

Summary: Use IS 2314 steel with specified copper content for corrosion resistance. Design for bending stresses using section modulus, and include corrosion allowance for durability in marine environments.

IS 9527 Part 3 (1983) – Loads and Forces for Sheet Pile Walls

Key Loads to Consider (Clause 7.1)

• Active & passive earth pressure
• Lateral earth pressure from surcharge
• Differential water & seepage pressure
• Mooring pull & ship impact (per IS 4651 Part III-1974)
• Wave pressure (per IS 4651 Part III-1974)
• Earthquake force (per IS 1893-1975)
• Handling and driving stresses

Load Calculation References (Clause 7.2.3)

• Mooring pull, ship impact, wave pressure: IS 4651 (Part III)-1974
• Earthquake forces: IS 1893-1975

Equivalent Beam Method (Clause 1.1)

For a unit length of wall, consider:

Typical Formula for Earth Pressure (Active)

[ P_a = \frac{1}{2} K_a \gamma H^2 ]

• (K_a) = Active earth pressure coefficient (from Rankine or Coulomb)
• (\gamma) = Unit weight of soil
• (H) = Height of wall

Summary Diagram (Equivalent Beam Method)

graph LR
  P1[Mooring Pull (P₁)] --> Wall[Sheet Pile Wall]
  Ap[Anchor Pull (Ap)] --> Wall
  Pw[Water Pressure (Pw)] --> Wall
  P2[Earth Pressure (P₂)] --> Wall
  Wall --> R0[Shear (R₀)]
  Wall --> Rc[Shear (R'c)]
  Wall --> Ra[Reaction (Ra)]

Note: For detailed wave, mooring, and earthquake loads, refer to IS 465

IS 9527 Part 3: Design of Sheet Pile Walls

1. Cantilever Sheet Pile Walls (Clause 8.1.1, Appendix A)

• Design Approach:

  • The sheet pile acts as a vertical cantilever beam embedded in soil.
  • Earth pressures on both sides are considered (active on retained side, passive on embedded side).
  • Check bending moments, shear forces, and deflections.

• Key Formula for Bending Moment (M):

  [ M_{max} = \frac{1}{6} \gamma H^3 K_a ]

  Where:

  • (\gamma) = unit weight of soil
  • (H) = height of retained soil
  • (K_a) = active earth pressure coefficient (from Rankine or Coulomb theory)

• Embedment Depth (d):

  [ d = H \sqrt{\frac{K_a}{K_p}} ]

  Where (K_p) = passive earth pressure coefficient.

2. Anchored Sheet Pile Walls (Clause 8.1.2, Appendix C)

• Design Method: Fixed-earth support method
• Key Parameters:
  • Anchor force calculated from earth pressure distribution.
  • Check for bending and shear in the sheet pile.
  • Ensure anchor capacity and soil bearing capacity.

3. Typical Earth Pressure Coefficients:

Where (\phi) = angle of internal friction of soil.

Summary Diagram

graph LR
A[Retained Soil] -->|Active Pressure \(K_a\)| B[Sheet Pile Wall]
B -->|Passive Resistance \(K_p\)| C[Embedded Soil]
B -->|Anchor Force (if anchored)| D[Anchor Support]

Note: For detailed thickness, steel grade, and section modulus, refer to Appendix A & C tables in IS 9527

IS 9527 Part 3: Cantilever Sheet Pile Walls (Appendix A)

Key Design Aspects (Clause 8.1.1 & Appendix A)

• Cantilever Sheet Pile Wall: Retains soil without anchors; stability from embedment depth.
• Design Parameters:
  • Soil properties: unit weight (γ), cohesion (c), friction angle (φ)
  • Water table location
  • Active and passive earth pressures (Rankine or Coulomb theories)

Key Formulas

1. Active Earth Pressure (Pa):

[ P_a = \frac{1}{2} \gamma H^2 K_a ]

• (H): height of retained soil
• (K_a = \tan^2(45^\circ - \frac{\phi}{2}))

2. Passive Earth Pressure (Pp):

[ P_p = \frac{1}{2} \gamma D^2 K_p ]

• (D): embedment depth
• (K_p = \tan^2(45^\circ + \frac{\phi}{2}))

3. Moment about the toe:

[ M = P_a \times \frac{H}{3} - P_p \times \frac{D}{3} ]

4. Shear force:

[ V = P_a - P_p ]

Design Checks

• Embedment depth (D) to balance moments and shear.
• Sheet pile section modulus for bending stresses.
• Factor of Safety: Usually 1.5 against overturning and sliding.

Typical Values for (K_a) and (K_p):

graph LR
A[Soil Retained] --> B[Active Earth Pressure (Pa)]
C[Embedment Depth (D)] --> D[Passive Earth Pressure (Pp)]
B --> E[Moment

Key Specifications & Design Guidelines for Ties (IS 9527 Part 3)

1. Tie Definition (Clause 2.2)

• Ties transfer load from walls to anchorages.
• Can be structural steel bars (round/square) or groups of high tensile wires/strands.

2. Tie Design Considerations (Clause 8.2)

• Tension Increase: Calculated tie tension must be increased by 20% to account for vertical loading.

  [ T_{design} = 1.2 \times T_{calculated} ]

• Corrosion Allowance: Increase cross-sectional area of ties to allow for corrosion losses.

• Slack Take-up: Provide turnbuckles on every tie.

• Settlement Issues: If soft soil is below ties:

  • Support ties with vertical piles at 6 to 8 m intervals reaching firm soil.
  • Or encase ties inside large pipes with inside diameter > expected settlement, resting ties on pipe invert.

3. Anchorages (Clause 8.3)

• Types: Sheet piles (cantilever/balanced), concrete anchor walls, shallow diaphragm walls, raking piles.
• Concrete anchors do not require walings but need full-depth excavation.
• Design per Clauses 8.3.1 to 8.3.9 and Appendix D guidance.

Summary Table: Tie Design Parameters

flowchart LR
    Wall -->|Load transfer| Tie
    Tie -->|Anchorage| Anchor
    Tie -->|Slack adjustment| Turnbuckle
    Tie -->|Settlement support| Piles
    Tie -->|Settlement support| Pipe

This concise layout ensures safe, durable tie design per IS 9527 Part 3.

IS 9527 Part 3: Anchored Sheet Pile Walls Key Points

Design Methods (Clause 8.1.2)

• Free Earth Support Method (Appendix B): Used when sheet piles penetrate soft clays or loose sands.
• Fixed Earth Support Method (Appendix C): Suitable for stiff clays or medium to dense sands; considers fixity at the top.

Fixed Earth Support Method (Appendix C) - Key Aspects

• Treat sheet pile as a beam fixed at the anchor level and supported by soil below.
• Calculate bending moments and shear forces assuming fixed support at anchor and soil reaction below.
• Soil pressure distribution usually assumed as triangular or trapezoidal based on soil properties.

Typical Formulas for Fixed Earth Support Method

• Bending moment at anchor level:

  [ M_a = \frac{w \times L^2}{2} ]

  Where:
  ( w ) = soil pressure intensity (kN/m²)
  ( L ) = embedded length below anchor (m)

• Anchor force:

  [ F_a = \frac{w \times L}{2} ]

• Sheet pile embedment depth:
  Determined by balancing moments and ensuring stability against overturning and sliding.

Typical Soil Pressure Distribution

Summary Diagram (Fixed Earth Support Method)

graph LR
A[Top of Sheet Pile] -- Anchor Force --> B[Anchor Rod]
B -- Fixed Support --> C[Embedded Length]
C -- Soil Reaction --> D[Soil]
A -- Soil Pressure --> D

References:

• IS 9527 Part 3, Clause 8.1.2 and Appendices B & C
• Soil parameters and embedment depth per site investigation data

For detailed design, refer to Appendix C for stepwise calculations and soil parameter selection.

IS 9527 Part 3: Overall Stability of Sheet Pile Walls

Key Points (Clause 8.6)

• Stability checked against failure along a slip surface using slip circle method.
• Analysis for both construction and long-term conditions.

Important Parameters (Clause 3.1)

Depth of Point of Inflexion (Clause 1.2, Table 1)

Stability Check Summary:

• Use slip circle method to find factor of safety (FOS) against sliding.
• Determine slip surface considering soil properties (¢, Y, Y'), wall friction (8), and embedment (D).
• Calculate forces including earth pressure, water pressure, and anchor pull (Ap).
• Adjust anchor line inclination (Clause 1.6) for horizontal force equilibrium.

Formula Snippet (Typical slip circle method):

[ \text{FOS} = \frac{\text{Sum of resisting moments}}{\text{Sum of driving moments}} \geq 1.5 \text{ (recommended)} ]

flowchart TD
    A[Sheet Pile Wall] --> B[Retained Soil (H)]
    B --> C[Slip Surface (Circle)]
    C --> D[Calculate Driving Forces]
    C --> E[Calculate Resisting Forces]
    D --> F[Moments about center]
    E --> F
    F --> G[Factor of Safety (FOS)]
    G --> H{FOS ≥ 1.5?}
    H -- Yes

IS 9527 Part 3: Requirements of Piles - Key Points

1. Types of Piles Covered

• Clause 9.1: Timber piles (refer to Part II for detailed timber pile design).
• Clause 9.2: Reinforced or Prestressed Concrete piles (refer to relevant concrete codes).

2. Material Specifications

• Steel Sheet Piles (Clause 4.1.4):
  • Steel shall conform to IS 2314-1963.
  • Copper content: 0.2% to 0.35% for corrosion resistance in seawater.

3. Stability Check (Clause 8.6)

• Overall stability of sheet pile walls must be checked via Slip Circle Method.
• Analyze for both construction stage and long-term conditions.

Typical Stability Analysis Formula (Slip Circle Method)

[ FS = \frac{\text{Sum of resisting moments}}{\text{Sum of driving moments}} \geq 1.5 \quad (\text{minimum for safety}) ]

Where:

• FS = Factor of Safety against sliding or overturning.

Summary Table: Pile Requirements

flowchart TD
    A[Pile Types] --> B[Timber Piles (9.1)]
    A --> C[Reinforced/Prestressed Concrete Piles (9.2)]
    A --> D[Steel Sheet Piles (4.1.4)]
    D --> E[IS 2314 Steel + 0.2-0.35% Cu]
    B --> F[Refer IS 9527 Part II]
    C --> G[Refer IS 456 & IS 1343]

Note: For detailed design, refer to IS 9527 Part II

IS 9527 Part 3: General Pile Requirements Summary

1. Overall Stability (Clause 8.6)

• Check sheet pile walls for stability using Slip Circle Method.
• Analyze for both construction and long-term conditions.
• Ensure no failure along potential slip surfaces.

2. Material Specifications

• Steel Sheet Piles: Conform to IS 2314-1963.
• Steel must contain 0.2% to 0.35% copper for seawater corrosion resistance.
• Types used:
  • Steel: Preferred for driving through hard strata & temporary works.
  • Reinforced/Prestressed Concrete: Used where driving is possible and watertightness is needed.
  • Timber: Only for favorable soils and low sectional modulus requirements.

3. Pile Types (Clause 9.2 & 6.1)

• Reinforced or prestressed concrete piles for permanent construction.
• Steel piles for temporary or where high driving resistance exists.

4. Key Design Considerations

• Ensure sectional modulus meets bending moment requirements.
• Watertightness critical for steel and concrete piles.
• Use appropriate pile type based on soil and loading conditions.

Typical Slip Circle Stability Check Formula:

[ FS = \frac{\text{Sum of resisting moments}}{\text{Sum of driving moments}} \geq 1.5 \quad (\text{recommended}) ]

Material Properties Summary

flowchart LR
    A[Soil & Load Conditions] --> B{Pile Type Selection}
    B -->|Hard strata / Temporary| C[Steel Sheet Piles]
    B -->|Favorable soil| D[Timber Piles]
    B -->|Permanent & Driveable| E[Reinforced/Prestressed Concrete P

IS 9527 Part 3: Reinforced and Prestressed Concrete Piles

Key Specifications:

• Materials:
  • Reinforced Concrete: As per IS 456-1978
  • Prestressed Concrete: As per IS 1343-1980

Design References:

• Reinforced Concrete Piles: Follow IS 456 guidelines for concrete strength, cover, and reinforcement detailing.
• Prestressed Concrete Piles: Follow IS 1343 for prestressing steel, losses, and prestressing force calculations.

Important Design Aspects:

Basic Formula for Prestressing Force (IS 1343):

[ P = A_p \times f_{pu} \times \eta ]

• (P) = Effective prestressing force after losses
• (A_p) = Area of prestressing steel
• (f_{pu}) = Ultimate tensile strength of prestressing steel
• (\eta) = Efficiency factor (considering losses)

Reinforcement Detailing (per IS 456):

• Minimum longitudinal reinforcement: 0.8% of cross-sectional area
• Maximum spacing of ties: 300 mm or diameter of the pile, whichever is less
• Adequate anchorage length as per IS 456

flowchart TD
    A[Start] --> B[Select Concrete Grade (IS 456)]
    B --> C[Select Prestressing Steel (IS 1343)]
    C --> D[Calculate Prestressing Force P]
    D --> E[Design Reinforcement (IS 456)]
    E --> F[Check Cover & Spacing]
    F --> G[Finalize Pile Design]

Summary: Use IS 456 for reinforced concrete

IS 9527 Part 3: Steel Sheet Piles - Key Points

Specifications:

• Steel sheet piles must conform to IS 2314-1963.
• Steel composition: 0.2% to 0.35% copper for corrosion resistance in seawater (Clause 4.1.4).
• Types of steel sheet piles (Clause 9.3.1):
  • Z-section: Clutches at edges, good for large bending moments.
  • U-section: Clutches at mid-depth.
  • Arch-web type: Used for high bending moment resistance.

Design Considerations:

• The theoretical section modulus (Z) depends on clutch friction.
• Z-section and arch-web piles are preferred for higher bending stresses.

Typical Formula:

For bending moment capacity, [ M_u = f_y \times Z ]

• (M_u) = ultimate bending moment capacity
• (f_y) = yield strength of steel
• (Z) = section modulus of pile cross-section

Reference Table: Typical Section Modulus (Example)

flowchart LR
    A[Steel Sheet Pile Types] --> B[Z-Section]
    A --> C[U-Section]
    A --> D[Arch-Web]
    B --> E[Clutches at edges]
    C --> F[Clutches at mid-depth]
    D --> G[High bending moment resistance]

Summary: Use IS 2314 steel with copper content 0.2-0.35% for corrosion resistance. Choose pile type based on bending moment demands, with Z and arch-web types for higher loads. Calculate bending capacity using (M_u = f_y \times Z).

IS 9527 Part 3 (1983) — Design Methods & Calculations Summary

1. Loads and Forces (Clause 7.2)

• Loads and forces on sheet pile walls are calculated as per Clauses 7.2.1 to 7.2.4 (details not fully provided here).

2. Fixed-Earth Support Method (Clause 8.1.2 & Appendix C)

• Used for anchored sheet pile walls design.
• The point of inflexion depth (x) below dredge level is interpolated from Table 1 based on soil friction angle (δ) and wall height (H).

• Figure 8 illustrates pressure distributions: active earth pressure and unbalanced water pressure.

3. Anchor Pull Reduction (Clause 5.1, Table D-5)

• For interference of unstable soil wedges, allowable anchor pull:

[ A_p = \left[(P_p - P_A) - (P'_p - P'_A)\right] \times F_s \times L ]

Where:

• (A_p) = allowable anchor pull
• (P_p, P'_p) = passive earth pressures
• (P_A, P'_A) = active earth pressures
• (L) = length of deadman
• (F_s) = factor of safety

Key Concept Diagram: Fixed-Earth Support Method

graph TB
  A[Ground Surface] --> B[Dredge Level]
  B --> C[Point of Inflexion, x]
  C --> D[Depth below dredge level]
  subgraph Pressure Distribution
    E[Active Earth Pressure]
    F[Net Soil Pressure Line]
    G[Unbalanced Water Pressure]
  end
  B --> E
  B --> F
  B --> G

Use these formulas and tables for design checks and interpolations as per IS 9527 Part 3. For detailed load calculations, refer to Clauses 7.2.1-7.2.4 and Appendix