Method of measurement of building and civil engineering works, Part 24: well foundations

IS 1200 Part 24: Scope & Key Specifications

Scope:

• Applies to method of measurement of well foundations for buildings and civil engineering works.
• Covers measurement of pneumatic sinking, steel cutting edges, steel armouring, and related operations.
• Separate standards exist for different trades (IS 1200 Parts 1 to 30).

Key Measurement Specifications (Clause 2.4):

Pneumatic Sinking Measurements (Clause 5.3):

• Separate measurement for:
  • Bringing/removing pneumatic sinking plant.
  • Use of plant (on well / not on well).
  • Fixing/removing adopter and airlock.
  • Corbel slab.
  • Keeping well under pressure (excluding sinking).

Additional Notes:

• Steel cutting edge and armouring measured per IS 1200 Part 8.
• Measurements rounded as per IS 2-1960.
• Provide site info: riverbed cross-section, water logging, strata details.

flowchart TD
    A[Start Well Foundation Work]
    B[Measure Linear Dimensions to 0.01 m]
    C[Measure Areas to 0.01 m²]
    D[Measure Cubic Contents to 0.01 m³]
    E[Pneumatic Sinking Plant Setup]
    F[Separate Measurement for Plant Use]
    G[Fixing/Removing Adopter & Airlock]
    H[Corbel Slab Measurement]
    I[Well Pressure Maintenance]
    
    A --> B --> C --> D --> E
    E --> F --> G --> H --> I

For detailed procedures, refer to IS 1200 Part 24 and related parts for steelwork (Part 8).

IS 1200 Part 24 — General Principles (Well Foundations)

Key Points:

• Separate Measurement: Clause 5.3 specifies separate measurement for:

  • Bringing/removing pneumatic sinking plant
  • Use of plant on/off well
  • Fixing/removing adopter and airlock
  • Corbel slab
  • Keeping well under pressure during plugging, guniting, repairs, inspection, testing (excluding sinking)

• Booking Dimensions (Clause 2.2): Dimensions should be booked in the order of length, width, and height/depth/thickness.

• Information to be Provided (Clause 0.5):

  • Description of work and river bed cross-section (low water and flood levels)
  • Water logging conditions
  • Soil strata and bore records

• Rounding Off (Clause 0.6): Final values must be rounded as per IS 2-1960 maintaining the same significant figures as specified.

Measurement Principles Summary

Additional References

• IS 1200 Part 8: Steelwork and ironwork measurement
• Safety Code: For working in compressed air (relevant to pneumatic sinking)

flowchart LR
    A[Start: Well Foundation Work] --> B{Pneumatic Sinking?}
    B -- Yes --> C[Measure Plant Installation/Removal Separately]
    B -- No --> D[Proceed with Normal Measurement]
    C --> E[Measure Use of Plant on Well and off Well Separately]
    E --> F[Measure Fixing/Removing Adopter & Airlock]
    F --> G[Measure Corbel Slab]
    G --> H[Measure Pressure Maintenance Activities]
    H --> I[Complete Measurement]
    D --> I

Summary: IS 1200 Part 24 emphasizes clear, separate measurement of distinct well foundation activities, consistent dimension booking, and accurate rounding off to maintain uniformity and

IS 1200 Part 24: Well Sinking - Key Points

Measurement & Specifications

• Measurement Unit: Running meters of sinking depth.
• Measurement Extent: From the level where the cutting edge (lowest part of the well curb) is pitched to the final resting level.
• Shape & Size: Must be stated during measurement.

Important Considerations

• Use of Kentiledge (a protective layer) is included for sinking and positional correction.
• Provide site-specific info:
  • Cross-section of river bed with low/high water levels.
  • Water logging conditions.
  • Soil strata or bore records.

Additional Notes

• Removal of obstructions (except standard ones) during sinking is measured separately on a quantum meruit basis.
• Final measurements should be rounded per IS 2-1960 guidelines.

Typical Formula for Volume of Well Sunk (for reference)

If well is circular:

[ \text{Volume} = \pi \times \left(\frac{d}{2}\right)^2 \times h ]

• (d) = diameter of well curb (m)
• (h) = sinking depth (m)

Diagram: Measurement of Well Sinking

flowchart LR
    A[Cutting Edge Level] -->|Sinking Depth (h)| B[Final Well Level]
    B --> C[Measurement in Running Meters]
    A --> D[Lowest Portion of Well Curb]

Summary:
Measure well sinking in running meters from the cutting edge to final level, include kentiledge use, document site conditions, and handle obstructions separately. Use IS 2 for rounding off measurements.

IS 1200 Part 24: Steining and Curb - Key Points

Measurement:

• Steining sinking: Measured in running metres from the cutting edge level (lowest part of well curb penetrating soil) to final resting level (Clause 3.3).
• Steining & curb concrete/brick/stone masonry: Measured in cubic metres, including formwork (Clause 4.1).
• Cutting off extra height of steining: Measured in cubic metres (Clause 4.6).
• Steel cutting edge & armouring: Measured separately as per IS 1200 Part 8 (Clause 4.5).

Specifications:

• Steining: Concrete/brick/stone masonry forming the well lining.
• Curb: Concrete top plug and curb providing a seal and support at the well top.

Typical Measurement Formula:

[ \text{Volume of Steining or Curb} = \text{Area} \times \text{Thickness or Height} ]

Where:

• Area = cross-sectional area of masonry/concrete
• Thickness/Height = as per design or measured on site

Summary Table:

flowchart TD
    A[Start: Well Sinking] --> B[Measure cutting edge level]
    B --> C[Sink steining to final level]
    C --> D[Measure sinking in running metres]
    D --> E[Construct steining & curb masonry/concrete]
    E --> F[Measure volume in cubic metres including formwork]
    F --> G[Cut off extra height if required; measure volume]
    G --> H[Measure steel cutting edge & armouring separately]

For detailed dimensions and reinforcement, refer to project-specific design drawings and IS 456 for concrete specifications.

IS 1200 Part 24: Pneumatic Sinking Key Points

Measurement:

• Sinking depth: Measured in running metres from the air introduction level to the stopping level (Clause 5.2).
• Shape & size: Must be stated along with running metres (Clause 3.3).
• Extra steining height cut-off: Measured in cubic metres (Clause 4.6).

Separate Measurements (Clause 5.3):

• a) Transport of pneumatic sinking plant to/from site.
• b) Use of plant on well and off well (measured separately).
• c) Fixing/removing adopter and airlock.
• d) Corbel slab.
• e) Maintaining pressure during plugging, guniting, repair, inspection, testing (excluding sinking).

Measurement Reference:

• Sinking measured from cutting edge level (lowest well curb portion penetrating soil) to final rest level.

Summary Table for Pneumatic Sinking Measurement

Notes:

• Refer IS 1200 Part 8 for steelwork related to pneumatic sinking.
• Safety code for compressed air work must be followed.

flowchart TD
    A[Pneumatic Sinking] --> B{Measurement}
    B --> C[Running Metres (Depth)]
    B --> D[Shape & Size]
    B --> E[Extra Steining Cut-off (m³)]
    A --> F{Separate Items}
    F --> G[Plant Transport]
    F --> H[Plant Usage On Well]
    F --> I[Plant Usage

IS 1200 Part 24: Measurement of Concrete and Masonry - Key Points

• Measurement Units:

  • Concrete, brickwork, stone masonry (steining, top plug, curb) measured in cubic metres (m³) including formwork (Clause 4.1).
  • Reinforcement (steel bars, links, binders) measured separately as per IS 1200 Part 8 (Clause 4.4).

• Measurement Precision (Clause 2.4):

  • Linear dimensions: nearest 0.01 m
  • Areas: nearest 0.01 m²
  • Volumes: nearest 0.01 m³

• Special Case (Clause 4.2):

  • Concrete in bottom plug (including sump) measured based on cement bags consumed.

Typical Volume Calculation Formula for Concrete/Masonry:

[ \text{Volume (m}^3) = \text{Length (m)} \times \text{Width (m)} \times \text{Height (m)} ]

Measurement Summary Table:

flowchart TD
    A[Start Measurement] --> B{Type of Work?}
    B -->|Concrete/Masonry| C[Measure volume (m³) incl. formwork]
    B -->|Reinforcement| D[Measure steel separately (IS1200 Part 8)]
    B -->|Bottom Plug Concrete| E[Measure via cement bags consumed]
    C --> F[Record to 0.01 m³]
    D --> F
    E --> F

This ensures consistent, precise measurement for billing and quality control.

IS 1200 Part 24: Measurement of Reinforcement - Key Points

• Reinforcement types: Mild steel bars, steel links, binders, steel flats measured separately as per IS 1200 Part 8 (1974).
• Steel cutting edge & armouring: Measured separately per IS 1200 Part 8 (1974).
• Measurement units & accuracy (Clause 2.4):
  • Linear dimensions: nearest 0.01 m
  • Areas: nearest 0.01 m²
  • Volumes: nearest 0.01 m³

Measurement Guidelines for Reinforcement

Calculation of Reinforcement Weight (if needed)

[ \text{Weight (kg)} = \text{Length (m)} \times \frac{\pi}{4} \times d^2 \times \rho ]

• ( d ) = diameter of bar (mm)
• ( \rho = 7.85 , \text{g/cm}^3 = 7850 , \text{kg/m}^3 )

Summary Diagram

flowchart TD
    A[Reinforcement Types] --> B[Mild Steel Bars]
    A --> C[Steel Links & Binders]
    A --> D[Steel Flats]
    A --> E[Steel Cutting Edge & Armouring]
    B --> F[Measured by length in meters]
    C --> F
    D --> F
    E --> G[Measured separately as per IS 1200 Part 8]

Note: Always refer to IS 1200 Part 8 for detailed measurement rules of steel items.

IS 1200 (Part 24) - Handling of Obstructions in Well Foundations

Key Points from Clause 2.7:

• Obstruction removal during well sinking is measured separately on a quantum meruit basis (payment based on actual work done).
• Obstructions requiring one tonne chisel for 24 hours are included under standard conditions.
• Other obstructions removed by mechanical or special methods are excluded here and handled separately.

Specifications:

• Measurement of obstruction removal is not lump-sum but based on actual effort and resources.
• If obstructions are removed by special equipment or methods, refer to specific clauses or contract terms.
• Extra cutting (e.g., steining height) is measured in cubic meters (Clause 4.6).

Practical Notes:

• For estimating, quantify obstruction volume or time of chisel use.
• Use quantum meruit to fairly compensate unforeseen obstructions.
• Ensure clear documentation of obstruction type and removal method.

Summary Table: Obstruction Handling

flowchart TD
    A[Encounter Obstruction] --> B{Type of Obstruction?}
    B -->|1-ton chisel < 24 hrs| C[Included in standard measurement]
    B -->|Mechanical/Special| D[Measure separately on quantum meruit]
    B -->|Extra Steining Cut| E[Measure in cubic meters]

This approach ensures fair measurement and payment for obstruction handling during well foundation sinking.

IS 1200 Part 24: Clubbing and Booking of Items - Key Points

1. Clubbing of Items (Clause 2.1)

• Items can be clubbed together if they are based on detailed descriptions in the standard.
• This helps in simplifying measurement and billing by grouping related tasks/materials.

2. Booking of Dimensions (Clause 2.2)

• Dimensions must be booked in a consistent order:
  • Length × Width × Height (or Depth/Thickness)
• This ensures uniformity and avoids confusion in measurements.

3. Description of Items (Clause 2.3)

• Each item’s description includes:
  • Conveyance, delivery, handling, loading/unloading, storing
  • Fabrication, hoisting, finishing to required shape/size
  • Setting, fitting, fixing, straight cutting, and waste allowance

4. Measurement Units (Clause 4.1)

• Concrete, brickwork, stone masonry in steining, top plug, and curb measured in cubic metres (m³)
• Formwork is included in the same item measurement.

Summary Table:

flowchart LR
    A[Start: Item Description] --> B{Can items be clubbed?}
    B -- Yes --> C[Club items as per detailed description]
    B -- No --> D[Measure separately]
    C --> E[Book dimensions: Length × Width × Height]
    D --> E
    E --> F[Include all labor & handling]
    F --> G[Measure concrete/brickwork in m³]
    G --> H[Include formwork in item]
    H --> I[End]

This approach ensures clarity and uniformity in measurement and billing as per IS 1200 Part 24.

IS 1200 Part 24: Bills of Quantities - Key Points

• Bill Description (Clause 2.6):
  Bills of Quantities (BoQ) must fully describe materials and workmanship and accurately represent the work to be executed.

• Measurement Precision (Clause 2.4):

  • Linear dimensions: nearest 0.01 m
  • Areas: nearest 0.01 m²
  • Volumes: nearest 0.01 m³

• Separate Measurement Items (Clause 5.3):
  Items like pneumatic sinking plant handling, fixing/removing accessories, corbel slabs, and well pressure maintenance are measured separately.

• Reinforcement Measurement (Clause 4.4):
  Reinforcement bars, links, binders, and flats are measured as per IS 1200 Part 8.

Measurement Formulae Summary

Recommended BoQ Structure

flowchart TD
    A[Bill of Quantities] --> B[Description of Materials]
    A --> C[Description of Workmanship]
    A --> D[Measurement of Work Items]
    D --> E[Linear Dimensions]
    D --> F[Areas]
    D --> G[Volumes]
    A --> H[Separate Items (e.g. Pneumatic Sinking)]
    A --> I[Reinforcement Quantities (IS 1200 Part 8)]

Note: For detailed reinforcement measurement, consult IS 1200 Part 8. Use decimal system consistently for clarity and accuracy.

IS 1200 Part 24 — Units and Rounding Off: Key Points

• Measurement Units:

  • Linear dimensions: nearest 0.01 m
  • Areas: nearest 0.01 m²
  • Cubic contents: nearest 0.01 m³

• Booking Order of Dimensions (Clause 2.2):

  • Sequence: Length → Width → Height/Depth/Thickness

• Rounding Off (Clause 0.6):

  • Follow IS 2:1960 rules for rounding.
  • Retain the same number of significant digits as specified values.
  • Final values (observed or calculated) must be rounded accordingly.

• Additional Notes:

  • Measurements for steel cutting edges and armouring are separate (refer IS 1200 Part 8).
  • Measurements are net and fixed in place.

Rounding Off Rules (IS 2:1960 Summary)

Measurement Sequence Example

flowchart LR
    A[Length] --> B[Width]
    B --> C[Height/Depth/Thickness]

This ensures consistent dimension booking for all trades as per IS 1200 Part 24.

IS 1200 Part 24 (1983) - Measurement Under Special Conditions for Well Foundations

Key Specifications:

• Clause 2.7 Note: Special conditions include removal of obstructions other than those removed by mechanical or special methods.
• Measurements shall be net and in decimal system:
  • Linear dimensions: nearest 0.01 m
  • Areas: nearest 0.01 m²
  • Cubic contents: nearest 0.01 m³ (Clause 2.4)

Measurement Guidelines under Special Conditions:

• Obstructions not removable by normal mechanical or special methods are measured separately.
• Include:
  • Bringing/removing pneumatic sinking plant (Clause 5.3a)
  • Use of pneumatic plant (fitted or not) (5.3b)
  • Fixing/removing adopter and airlock (5.3c)
  • Corbel slab (5.3d)
  • Keeping well under pressure during plugging, guniting, etc. (5.3e)

Recommended Measurement Rounding:

• Follow IS 2-1960 rounding rules to maintain consistency.

Summary Table: Measurement Units & Precision

Conceptual Flow of Special Condition Measurement

flowchart TD
    A[Start Measurement] --> B{Obstruction Type?}
    B -->|Mechanical/Special Method| C[Exclude from Special Conditions]
    B -->|Other Obstructions| D[Measure Separately]
    D --> E[Record Plant Use & Handling]
    E --> F[Include Corbel Slab, Pressure Maintenance]
    F --> G[Round off as per IS 2-1960]
    G --> H[Finalize Measurement]

For detailed item-wise measurement, refer to Clause 5.3 of IS 1200 Part 24.

Note: Always accompany measurements with site-specific data like soil strata, water levels, and obstructions for clarity.