Method of measurement of building and civil engineering works, Part 24: well foundations
1983 Edition

Scope Overview:

• Applicable to measurement methods for well foundations in building and civil engineering works.
• Includes measurement of pneumatic sinking procedures, steel cutting edges, steel armouring, and associated tasks.
• Other IS 1200 parts (1 to 30) cover various related trades.

Measurement Accuracy (Clause 2.4):

Pneumatic Sinking Specifics (Clause 5.3):

• Separate measurement for:
  • Transporting pneumatic sinking equipment.
  • Operating plant on and off the well.
  • Installing and removing adopter and airlock.
  • Corbel slab construction.
  • Maintaining well pressure during non-sinking activities.

Additional Details:

• Steel cutting edges and armouring measured per IS 1200 Part 8.
• Measurement rounding follows IS 2-1960.
• Site information such as riverbed profiles, water logging, and soil strata must be documented.

flowchart TD
    A[Initiate Well Foundation Work]
    B[Measure Linear Dimensions to 0.01 m]
    C[Measure Surface Areas to 0.01 m²]
    D[Measure Volumes to 0.01 m³]
    E[Set Up Pneumatic Sinking Equipment]
    F[Measure Equipment Transport Separately]
    G[Measure Equipment Usage Separately]
    H[Account for Adopter & Airlock Installation]
    I[Measure Corbel Slab]
    J[Record Well Pressure Maintenance]
    
    A --> B --> C --> D --> E
    E --> F --> G --> H --> I --> J

Refer to IS 1200 Part 24 and Part 8 for comprehensive measurement instructions.

Core Principles in Well Foundation Measurement (IS 1200 Part 24)

• Distinct Measurements (Clause 5.3): Separate quantification for:

  • Transport and removal of pneumatic sinking plants.
  • Usage of plant when fitted on or off the well.
  • Installation and removal of adopter and airlock.
  • Corbel slab construction.
  • Well pressure maintenance during plugging, guniting, repairs, inspections, and tests (excluding sinking).

• Dimension Booking (Clause 2.2): Record dimensions consistently in the order of length, width, and height/depth/thickness.

• Site Information (Clause 0.5): Provide detailed descriptions including work nature, riverbed cross-section (low and high water levels), water logging, and soil strata or borehole data.

• Rounding Off (Clause 0.6): Round final measurement results in accordance with IS 2-1960, preserving the specified significant figures.

Additional References

• IS 1200 Part 8 for steelwork measurement.
• Safety codes applicable to compressed air work during pneumatic sinking.

flowchart LR
    A[Begin Well Foundation Task] --> B{Is Pneumatic Sinking Involved?}
    B -- Yes --> C[Measure Plant Installation/Removal Separately]
    B -- No --> D[Proceed with Standard Measurement]
    C --> E[Track Plant Usage On Well and Off Well]
    E --> F[Record Adopter & Airlock Installation/Removal]
    F --> G[Measure Corbel Slab]
    G --> H[Account for Pressure Maintenance Activities]
    H --> I[Complete Measurement Process]
    D --> I

Summary: IS 1200 Part 24 prioritizes distinct and accurate measurement of well foundation activities, consistent dimension recording, and precise rounding to ensure uniformity.

Measurement Guidelines for Well Sinking (IS 1200 Part 24)

• Unit of Measurement: Running meters representing the depth of sinking.
• Measurement Range: From the level at which the cutting edge (lowest portion of the well curb penetrating subsurface) is positioned down to the final resting level.
• Specification: The shape and dimensions of the well must be recorded alongside measurement.

Important Notes:

• Inclusion of kentiledge (protective layer) in sinking and positional adjustment is considered.
• Essential site details include:
  • Riverbed cross-section illustrating low and flood water levels.
  • Water logging conditions.
  • Soil strata and borehole records.

Additional Considerations:

• Obstruction removal, except standard cases, is measured separately on a quantum meruit basis.
• Measurements are to be rounded off according to IS 2-1960.

Volume Calculation (Circular Wells):

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

Where:

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

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

Summary: Well sinking is measured in running meters from the cutting edge pitch to final depth, including kentiledge and site conditions, with obstruction handling treated separately.

Key Measurement Aspects for Steining and Curb (IS 1200 Part 24)

• Steining sinking depth: Recorded in running meters from the cutting edge level to the final resting point (Clause 3.3).
• Steining and curb concrete, brickwork, or stone masonry: Measured in cubic meters, including formwork (Clause 4.1).
• Extra steining height removal: Measured in cubic meters (Clause 4.6).
• Steel cutting edges and armouring: Measured separately as per IS 1200 Part 8 (Clause 4.5).

Definitions:

• Steining: Masonry or concrete lining forming the well wall.
• Curb: Concrete top plug and curb that seal and support the well's upper part.

Volume Calculation Formula:

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

Where:

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

flowchart TD
    A[Commence Well Sinking] --> B[Record Cutting Edge Level]
    B --> C[Sink Steining to Final Depth]
    C --> D[Measure Sinking Depth in Running Meters]
    D --> E[Construct Steining and Curb Masonry/Concrete]
    E --> F[Measure Volume Including Formwork]
    F --> G[Cut Off Excess Steining Height; Measure Volume]
    G --> H[Measure Steel Cutting Edge and Armouring Separately]

Refer to project-specific drawings and IS 456 for detailed reinforcement and concrete specifications.

Measurement Protocols for Pneumatic Sinking (IS 1200 Part 24)

• Sinking Depth: Measured in running meters from the air introduction level to the stopping level (Clause 5.2).
• Shape and Size: Must be recorded along with the running meter measurement (Clause 3.3).
• Extra Steining Height Cut-off: Quantified in cubic meters (Clause 4.6).

Separate Measurement Items (Clause 5.3):

• a) Transportation of pneumatic sinking equipment to and from the site.
• b) Usage of the plant both when mounted on the well and when off the well (measured separately).
• c) Installation and removal of adopter and airlock.
• d) Construction of corbel slab.
• e) Maintenance of well pressure during plugging, guniting, repairs, inspections, and testing (excluding sinking).

Reference Measurement:

• Sinking measured from the cutting edge level to the final resting depth.

Notes:

• Measurement of steelwork related to pneumatic sinking refers to IS 1200 Part 8.
• Compressed air safety codes must be strictly adhered to.

flowchart TD
    A[Pneumatic Sinking Operation] --> B{Measurement Components}
    B --> C[Running Meters for Depth]
    B --> D[Shape and Size Recording]
    B --> E[Extra Steining Cut-off Volume]
    A --> F{Additional Separate Items}
    F --> G[Transport of Equipment]
    F --> H[Equipment Usage On Well]
    F --> I[Equipment Usage Off Well]
    F --> J[Adopter and Airlock Fixing/Removal]
    F --> K[Corbel Slab Measurement]
    F --> L[Pressure Maintenance Activities]

Measurement of Concrete and Masonry Components (IS 1200 Part 24)

• Units Used:

  • Concrete, brickwork, and stone masonry related to steining, top plug, and curb are measured in cubic meters (m³) including the formwork (Clause 4.1).
  • Reinforcement elements (steel bars, links, binders) are measured independently according to IS 1200 Part 8 (Clause 4.4).

• Measurement Accuracy (Clause 2.4):

  • Linear dimensions to the nearest 0.01 m
  • Surface areas to the nearest 0.01 m²
  • Volumes to the nearest 0.01 m³

• Special Measurement Case (Clause 4.2):

  • Concrete in the bottom plug, including sump area, can be measured based on the number of cement bags used.

Volume Calculation Formula:

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

flowchart TD
    A[Begin Measurement] --> B{Type of Work}
    B -->|Concrete/Masonry| C[Measure Volume Including Formwork]
    B -->|Reinforcement| D[Measure Steel Separately]
    B -->|Bottom Plug Concrete| E[Measure Based on Cement Consumption]
    C --> F[Record Measurements to 0.01 m³]
    D --> F
    E --> F

This methodology ensures precise and consistent measurement for billing and quality assurance.

Reinforcement Quantification (IS 1200 Part 24)

• Types Covered: Mild steel bars, steel links, binders, and steel flats are measured separately as per IS 1200 Part 8 (1974).
• Steel Cutting Edge and Armouring: Also measured independently following IS 1200 Part 8.
• Accuracy for Measurement (Clause 2.4):
  • Linear dimensions to 0.01 m
  • Surface areas to 0.01 m²
  • Volumes to 0.01 m³

Weight Calculation for Reinforcement (if required):

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

Where:

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

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

Note: Refer to IS 1200 Part 8 for detailed reinforcement measurement protocols.

Obstruction Management in Well Foundations (IS 1200 Part 24, Clause 2.7)

• Any obstructions encountered during well sinking, other than those removable by a one-ton chisel operated for 24 hours, are to be measured separately on a quantum meruit basis (payment based on actual work done).
• Standard obstructions handled by one-ton chisel within 24 hours are included in normal measurement.
• Obstructions requiring special mechanical or alternative removal methods are excluded from lump-sum measurement and must be accounted for separately.

Measurement Approach:

• Obstruction removal is not measured as a lump sum but according to actual effort and resources expended.
• Additional cutting (such as extra steining height removal) is measured in cubic meters (Clause 4.6).

Practical Guidelines:

• Estimate obstruction volume or time spent using chisel.
• Use quantum meruit payment to fairly compensate for unforeseen obstructions.
• Maintain thorough documentation of obstruction nature and removal method.

flowchart TD
    A[Detect Obstruction] --> B{Obstruction Type}
    B -->|1-ton chisel < 24 hrs| C[Include in Standard Measurement]
    B -->|Mechanical/Special Removal| D[Measure Separately on Quantum Meruit]
    B -->|Extra Steining Cut-off| E[Measure in Cubic Meters]

This ensures equitable measurement and remuneration for obstruction handling during well sinking.

Item Clubbing and Booking Procedures (IS 1200 Part 24)

• Clubbing of Items (Clause 2.1): Items may be combined when detailed descriptions in the standard justify grouping, simplifying measurement and billing.

• Dimension Booking (Clause 2.2): Dimensions should be recorded in a consistent sequence: Length × Width × Height (or Depth/Thickness).

• Item Descriptions (Clause 2.3): Each item description must encompass all aspects including transportation, handling, loading/unloading, storage, fabrication, hoisting, finishing to required dimensions, setting, fitting, fixing, cutting, and waste allowance.

• Measurement Units (Clause 4.1): Concrete, brickwork, and stone masonry in steining, top plug, and curb are measured in cubic meters, inclusive of formwork.

flowchart LR
    A[Start: Define Item Description] --> B{Can Items be Clubbed?}
    B -- Yes --> C[Group Items per Standard Description]
    B -- No --> D[Measure Items Individually]
    C --> E[Record Dimensions: Length × Width × Height]
    D --> E
    E --> F[Include Labor and Handling]
    F --> G[Measure Concrete/Brickwork in Cubic Meters]
    G --> H[Include Formwork in Item]
    H --> I[End Process]

This method promotes clarity and consistency in measurement and billing as outlined by IS 1200 Part 24.

Bills of Quantities (BoQ) Guidelines (IS 1200 Part 24)

• Bill Descriptions (Clause 2.6): BoQs should fully define the materials and workmanship and accurately reflect the scope of work.

• Measurement Accuracy (Clause 2.4):

  • Linear dimensions rounded to 0.01 m
  • Areas rounded to 0.01 m²
  • Volumes rounded to 0.01 m³

• Separate Measurement Items (Clause 5.3): Items such as handling of pneumatic sinking plants, fixing/removal of accessories, corbel slabs, and well pressure maintenance are measured separately.

• Reinforcement Measurement (Clause 4.4): Reinforcement quantities are to be measured following IS 1200 Part 8.

flowchart TD
    A[Bills of Quantities] --> B[Material Descriptions]
    A --> C[Workmanship Details]
    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 reinforcement details, consult IS 1200 Part 8 and consistently use decimal system for clarity.

Units and Rounding (IS 1200 Part 24)

• Standard Units:

  • Linear measurements: nearest 0.01 m
  • Surface areas: nearest 0.01 m²
  • Volume measurements: nearest 0.01 m³

• Dimension Booking Order (Clause 2.2): Record in sequence: Length → Width → Height/Depth/Thickness.

• Rounding Rules (Clause 0.6): Follow IS 2:1960 ensuring the same number of significant digits as the original data.

• Additional Notes:

  • Steel cutting edges and armouring measurements are separate (see IS 1200 Part 8).
  • Measurements are net and based on fixed in-place work.

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

This system ensures consistency in dimension recording across all trades.

Special Conditions Measurement (IS 1200 Part 24, 1983)

• Clause 2.7 Note: Special cases include removal of obstructions not handled by mechanical or special methods.

• Measurements are net and expressed in decimal units:

  • Linear: to 0.01 m
  • Area: to 0.01 m²
  • Volume: to 0.01 m³ (Clause 2.4)

• Items to be measured separately under special conditions include:

  • Transportation of pneumatic sinking plant (Clause 5.3a)
  • Usage of pneumatic plant, both fitted and not fitted (5.3b)
  • Installation/removal of adopter and airlock (5.3c)
  • Corbel slab works (5.3d)
  • Well pressure maintenance during plugging, guniting, etc. (5.3e)

• Measurements must be rounded following IS 2:1960 to maintain uniformity.

flowchart TD
    A[Begin Measurement] --> B{Type of Obstruction}
    B -->|Mechanical/Special| C[Exclude from Special Conditions]
    B -->|Other Obstructions| D[Measure Separately]
    D --> E[Record Plant Handling]
    E --> F[Include Corbel Slab and Pressure Maintenance]
    F --> G[Apply IS 2-1960 Rounding]
    G --> H[Finalize Measurement]

Consult Clause 5.3 of IS 1200 Part 24 for detailed item measurements. Always accompany measurements with relevant site data such as soil profiles, water levels, and obstruction details.