shear box for testing soils
1985 Edition

Scope Overview (Clauses 3.1 & 4.1)

• Defines the required materials and dimensional criteria for shear box components used in soil shear strength testing.
• Materials must comply with designated Indian Standards.

Material Reference Table:

Dimensional Requirements (Clause 4.1)

• Dimensions detailed in Figures 2 to 7 of the standard.
• Tolerances conform to IS 2102 (Part 1) - 1980 medium class.

Additional Notes:

• Equipment may carry the ISI Certification Mark indicating compliance.

Diagram of Shear Box Elements:

graph TD
  U[Upper Section] -->|Pinned Connection| L[Lower Section]
  U --> G[Grid Plates (2 pairs)]
  L --> B[Base Plate]
  U --> T[Top Plate]
  U --> P[Loading Pad]
  U --> W[Water Jacket]
  L --> S[Stone Plates]

This section outlines the scope, material requirements, and dimensional controls for shear box components.

Key Components (Clause 2.1)

• Upper and lower shear box parts connected via two pins.
• Two pairs of grid plates inside the assembly.
• Stone plates positioned above and below the soil sample.
• Loading pad used to apply vertical load.
• Water jacket enclosing the box to maintain moisture conditions.

Dimensional Details (Clause 4.1)

• Dimensions as per Figures 2 through 7.
• Tolerances following IS 2102 (Part 1) - 1980 medium class.

Typical Measurements:

Notes:

• The shear box dimensions depend on soil type and test requirements.
• Pins ensure proper alignment and smooth sliding.
• Water jacket must be leak-proof for saturation tests.

flowchart LR
    U[Upper Shear Box] -- Pins --> L[Lower Shear Box]
    L --> G[Grid Plates (2 pairs)]
    G --> Soil[Soil Sample]
    Soil --> S[Stone Plates]
    S --> P[Loading Pad]
    P --> W[Water Jacket]

This assembly ensures controlled shear testing under specified parameters. Refer to IS 11229 Figures 2-7 for precise dimensions.

Dimensions and Tolerances According to IS 11229

• Dimensions: Specified in Figures 2 to 7, measured in millimeters.
• Tolerance Classification: Medium class tolerances as per IS 2102 (Part 1) - 1980.
• Hole Tolerances: For holes (e.g., four holes on each side), a tolerance of +1 mm is permitted.

Material Dimensions:

• Stone plates: 60 x 60 x 6 mm (Sandstone complying with IS 3622-1977).
• Other components: Mild steel or brass conforming to IS 513-1973 and IS 292-1983.

Tolerance Table (IS 2102 Part 1 medium class):

Important Notes:

• Strict adherence to these dimensions and tolerances is necessary for interchangeability and accurate test performance.
• ISI mark confirms compliance with these requirements.

flowchart TD
    D[Shear Box Dimensions] --> F[Figures 2-7]
    D --> T[Tolerances per IS 2102 Part 1]
    T --> M[Medium Class Tolerances]
    F --> H[Hole Tolerance: +1 mm]
    F --> S[Stone Plate: 60x60x6 mm]
    F --> Mat[Material: Mild Steel/Brass]

Consult Figures 2-7 in IS 11229 and IS 2102 for exact dimensional and tolerance details.

Material Requirements and Marking (Clauses 3.1, 5.1 & Table 1)

• Mild steel refers to cold rolled carbon steel sheets.
• Brass materials conform to specifications for ingots and castings.
• Sandstone slabs are selected to specified dimensions.

Marking Requirements:

• Each part must be permanently and clearly marked with:

  • Manufacturer's name or registered trademark.
  • Material type.
  • Date of manufacture.

• ISI Certification Mark may be optionally applied, demonstrating compliance with quality and inspection norms.

Summary Table:

graph TD
  A[Shear Box Parts] --> B[Upper & Lower Sections]
  A --> C[Grid Plates]
  A --> D[Stone Plates]
  A --> E[Base Plate]
  A --> F[Top Plate]
  A --> G[Loading Pad]
  A --> H[Water Jacket]

Clear marking ensures traceability and quality assurance.

Assembly and Connection of Shear Box Components (Clause 2.1 & 4.1)

• The upper and lower parts are joined by two pins ensuring alignment.
• Two pairs of grid plates are assembled inside.
• Stone plates are placed above and below the soil sample.
• The loading pad is positioned for vertical load application.
• A water jacket surrounds the assembly.

Material Standards:

Dimensional Tolerances:

• Dimensions as per Figures 2-7.
• Tolerances according to IS 2102 (Part 1)-1980 medium class.
• Hole tolerance: Four holes with +1 mm tolerance each side.

Assembly Notes:

• Pin coupling ensures proper alignment and effective shear load transfer.
• Holes on all four sides facilitate assembly with specified tolerances.
• Knurling and adjustable screws enable precise fitting.

Assembly Diagram:

graph TD
  U[Upper Shear Box Half] -->|Pinned Connection| L[Lower Shear Box Half]
  L --> B[Base Plate]
  U --> P[Loading Pad]
  L --> S[Stone Plates]
  U --> G[Grid Plates (2 pairs)]
  U --> W[Water Jacket]

This arrangement provides a standardized, robust assembly for reliable shear testing.

Water Jacket Requirements According to IS 11229

• Material: Constructed from mild steel or brass conforming to IS 513-1973 and IS 292-1983.
• Dimensions: Specified in Figure 7, measured in millimeters.
• Tolerances: Follow IS 2102 (Part 1)-1980 medium class.

Function:

• The water jacket is a thin metal enclosure surrounding the shear box to allow water circulation, maintaining moisture and temperature conditions during testing.
• Proper sealing and fitting are essential to prevent leaks.

Typical Specifications:

Water Jacket Assembly Diagram:

graph LR
  L[Lower Shear Box Half] -- Attached to --> W[Water Jacket]
  W -- Attached to --> U[Upper Shear Box Half]
  W -. Water Circulation .-> H[Water Inlet/Outlet Holes]

Refer to Figure 7 and IS 2102 Part 1 for precise sizing and tolerances.

Quality Control and Certification Highlights (Clause 5.1.1)

• The ISI mark certifies that the shear box complies with IS 11229 requirements, supported by rigorous inspection, testing, and quality control.
• Licensing and application of the ISI mark are regulated under the Indian Standards Institution (Certification Marks) Act.
• Ongoing ISI surveillance ensures persistent conformity to the standard.

Material Compliance:

Test Result Reporting:

• Final test data should be rounded as per IS 2-1960 rules for numerical rounding.

Quality Control Flowchart:

flowchart TD
  M[Manufacturing] --> I[Inspection & Testing]
  I --> C{Conforms to IS 11229?}
  C -- Yes --> S[ISI Certification Granted]
  C -- No --> R[Rectification and Re-testing]
  S --> O[Continuous ISI Surveillance]

For detailed certification and quality protocols, consult the Indian Standards Institution guidelines.

Reporting and Numerical Rounding per IS 11229 and IS 2:1960

• Final test results (whether recorded or computed) must be rounded following IS 2:1960 rounding rules.

Rounding Rules Summary:

• If the digit to be discarded is less than 5, the preceding digit stays the same.
• If greater than 5, increase the preceding digit by one.
• If exactly 5, round to the nearest even digit to avoid bias.
• Maintain the required decimal precision as per the test.

Examples:

• 12.234 rounded to two decimals is 12.23.
• 12.235 rounded to two decimals becomes 12.24 (since the digit to drop is 5 and the preceding digit is odd).

Additional Note:

• IS 11229 does not provide rounding rules but defers to IS 2:1960.

Rounding Summary Table:

flowchart TD
  V[Final Test Value] --> D{Digit to Drop}
  D -->|<5| N[No Change]
  D -->|>5| I[Increment by 1]
  D -->|=5| E{Previous Digit Even?}
  E -->|Yes| N
  E -->|No| I

This ensures consistent and objective reporting of soil shear test data.