Prestressed concrete circular spun poles for overhead power, traction and telecommunication lines

IS 13158: Scope and Key Specifications Summary

• Scope: Covers prestressed concrete circular spun poles used for electrical distribution and transmission.

• Depth of Planting (Clause 6.4 & Table 1):
  Minimum embedment depths depend on pole length to ensure stability.

• Rounding Off Values: Follow IS 2:1960 for numerical rounding, maintaining significant digits as per specified values.

• Reference Standards: Annex A lists related Indian Standards essential for complete compliance.

This ensures poles are embedded deep enough for structural stability per length and ground conditions.

IS 13158 Key References & Specifications

• Rounding Off (Clause None):
  Follow IS 2:1960 for rounding numerical values. Retain the same number of significant places as the specified value.

• Referenced Standards (Clause 2.1):
  Annex A lists Indian Standards essential to IS 13158 compliance.

• Definitions (Clause 3.0):
  Standard definitions apply as per Clause 3.0.

• Minimum Depth of Planting (Clause 6.4 & Table 1):
  Depth depends on pole length and ground conditions.

Summary:
Use Table 1 for planting depth based on pole length. Always round off as per IS 2:1960. Refer Annex A for related IS codes.

IS 13158 - Definitions Summary

Clause 3.0 defines terms used in IS 13158 to ensure clarity and uniform interpretation.

Key Points:

• Rounding Off (per IS 2:1960):

  • Final values (test or analysis results) must be rounded off according to IS 2:1960 rules.
  • Retain the same number of significant digits as specified in the standard.

• Referenced Standards:

  • Annex A lists Indian Standards essential to IS 13158 compliance.

Important Notes:

• No explicit formulas or tables are provided under "Definitions."
• Definitions ensure consistent terminology for structural elements, materials, and testing procedures.
• For calculations, always refer to IS 2:1960 for rounding rules.

Example: Rounding Rule (IS 2:1960)

If you need specific definitions or formulas from other clauses, please specify!

IS 13158: Overall Length of Poles - Key Points

1. Overall Length Tolerance (Clause 4.2)

• Tolerance on overall length: ± 15 mm
• Tolerance on outside diameter: +4 mm (exact tolerance value missing in context)
• Tolerance on uprightness: 0.5% (unless otherwise specified)

2. Depth of Planting (Clause 6.4, Table 1)

3. Working Load (Clause 3.7)

• Maximum transverse load acts 600 mm below the top of the pole.
• Butt end planted to the required depth as per design.

4. Quality Control (Clause 9.2.1)

• Poles tested for overall length, cross-section, and uprightness.
• Defective poles count must be ≤ acceptance number in Table 2 for lot conformity.

Summary Diagram: Pole Length & Planting Depth

graph TD
    A[Overall Length of Pole] --> B[± 15 mm Tolerance]
    A --> C[Uprightness ≤ 0.5%]
    A --> D[Diameter Tolerance +4 mm]

    A --> E[Planting Depth]
    E --> F{Pole Length Range}
    F -->|6.0-7.0 m| G[1.20 m Depth]
    F -->|7.5-9.0 m| H[1.50 m Depth]
    F -->|

IS 13158: Materials - Key Specifications & Formulas

1. Permissible Design Stresses (Clause 6.5.4):

• Concrete compressive stress (under average permanent load): As per IS 1343:1980.

• Concrete flexural tensile stress (under average permanent load):
  [ f_{ct,perm} = 3.0 , \text{N/mm}^2 ]

• High tensile steel stresses: Follow IS 1343:1980 guidelines.

2. Rounding Off (General):

• Use IS 2:1960 for rounding numerical values.
• Retain the same number of significant figures as specified in the standard.

3. Reference Standards (Clause 2.1):

• IS 1343:1980 (prestressed concrete) for stress limits.
• IS 2:1960 for numerical rounding.
• Annex A lists other relevant Indian Standards.

Summary Table: Permissible Design Stresses

flowchart TD
    A[Materials in IS 13158] --> B[Concrete]
    A --> C[High Tensile Steel]
    B --> D[Compressive Stress per IS 1343]
    B --> E[Flexural Tensile Stress = 3.0 N/mm²]
    C --> F[Design Stresses per IS 1343]
    A --> G[Rounding off per IS 2:1960]

For detailed material properties and stress limits, always cross-check with IS 1343:1980 and related IS codes listed in Annex A.

IS 13158: Design Requirements - Key Formulas, Tables, and Specifications

1. Depth of Planting (Clause 6.4)

Minimum embedment depth of prestressed concrete circular spun poles depends on pole length:

Actual depth may vary depending on soil and ground conditions.

2. Transverse Load at First Crack (Clause 3.4)

• The transverse load causing the first crack must be ≥ working load.
• This ensures safety against initial cracking under service conditions.

3. Rounding Off (General Clause)

• Final calculated or observed values must be rounded per IS 2:1960.
• Number of significant digits retained should match the specified values in the standard.

4. References

• Use Indian Standards listed in Annex A for related design adjuncts.

Summary:

• Use Table 1 for minimum pole embedment.
• Ensure transverse load capacity ≥ working load.
• Follow IS 2:1960 for rounding numerical results.

flowchart LR
    A[Pole Length] --> B{Check Length Range}
    B -->|6-7 m| C[Embed 1.20 m]
    B -->|7.5-9 m| D[Embed 1.50 m]
    B -->|9.5-11 m| E[Embed 1.80 m]
    B -->|11.5-13

IS 13158: Manufacture of Prestressed Concrete Spun Poles — Key Points

1. Manufacturing Requirements

• Moulds (Clause 7.1.1):
  • Made of steel, rigid to prevent distortion.
  • Smooth internal surfaces.
  • No leakage of cement grout during spinning.
  • End plates with accurately drilled holes (via jigs) for HT wires ensuring interchangeability.
  • End plates designed to withstand forces from prestressing wire tension changes.

2. Testing During Manufacture (Clause 8.1 & 7.6)

• Concrete tests as per Clause 7.6 must be conducted during manufacture to ensure quality.

3. Sampling & Acceptance Criteria (Clause 9.1.3, Table 2)

• Note: Poles tested up to first crack can be used if cracks close after load removal.

4. Rounding Off Results (Clause None)

• Final test results must be rounded per IS 2:1960 rules, retaining the same significant figures as specified.

flowchart TD
    A[Mould Preparation] --> B[Spinning Process]
    B --> C[Concrete Testing (Clause 7.6)]
    C --> D[Sampling (Table 2)]
    D --> E{Acceptance Criteria}
    E -->|Pass| F[Dispatch Poles]
    E -->|Fail| G[Rework/Reject]

This summarizes key manufacturing and quality control provisions per IS 13158.

IS 13158: Testing - Key Formulas, Tables, and Specifications

1. Number of Tests and Sampling (Clause 9.1.3 & Table 2)

• Note: Poles tested up to first crack can be used if cracks close after load removal.

2. Transverse Strength Test (Clause 8.2)

• Conducted as per IS 2905:1989.
• Failure criteria:
  • Cracks > 0.1 mm before design first crack load → Fail.
  • Ultimate transverse load < design ultimate load → Fail.

3. Rounding Off (Clause 9.2)

• Final test results must be rounded per IS 2:1960.
• Retain the same number of significant digits as specified in IS 13158.

Summary Flow:

flowchart TD
    A[Select Lot Size] --> B[Determine Sample Size & Acceptance Numbers (Table 2)]
    B --> C[Conduct Dimensional & Transverse Strength Tests]
    C --> D{Test Results}
    D -->|Meets Criteria| E[Accept Lot]
    D -->|Fails Criteria| F[Reject Lot]

This ensures quality control of spun concrete poles via statistically valid sampling and strict transverse strength criteria.

IS 13158: Sampling and Inspection Key Points

1. Sampling Scale (Clause 9.1.3 & Table 2)

• Note: Poles tested up to first crack can be accepted if cracks close after load removal.

2. Number of Tests & Conformity (Clause 9.2)

• Tests must meet acceptance numbers for dimensional and strength criteria.
• Final test values are rounded per IS 2:1960 rules, maintaining the same decimal places as specified.

Summary:

• Sample size depends on lot size.
• Acceptance numbers vary for dimensional and strength tests.
• Use IS 2 for rounding off test results.

flowchart TD
    A[Lot Size] --> B{Select Sample Size}
    B -->|Up to 100| C[Sample 10]
    B -->|101-200| D[Sample 15]
    B -->|201-300| E[Sample 20]
    B -->|301-500| F[Sample 30]
    C --> G[Check Dimensional Defects ≤1]
    C --> H[Check Strength at First Crack ≤2]
    C --> I[Check Ultimate Strength ≤1]
    %% similar for other samples

This ensures quality control per IS 13158 standards.

IS 13158: Marking and Packing Key Points

Marking (Clause 10.1)

Poles must be clearly and indelibly marked before testing, at a visible position after erection, with:

• Month and year of manufacture
• Manufacturer’s name or registered trademark
• Serial number of the pole
• Position of center of gravity marked as "C.G."

Sampling & Acceptance (Clause 9.1.3 & Table 2)

• Note: Poles tested up to first crack are acceptable if cracks close after load removal.

Rounding Off (General)

• Final test values must be rounded as per IS 2:1960, retaining the same number of significant digits as specified.

This ensures traceability, quality control, and compliance during manufacturing and testing of spun concrete poles.