Methods of measurement of building and civil engineering works, Part 1: Earthwork

IS 1200 Part 1: Scope & Key Specifications

• Scope: Methods for measurement of building and civil engineering works (excluding river valley projects). Applies to excavation, pumping, and classification of materials.

Classification of Excavated Materials (Clause 3)

Measurement of Pumping (Clause 2.7)

• Special pumping (other than standard dewatering) measured in KW-hrs or HP-hrs for all stages including intermediate pumping.

Rounding Off (General)

• Use IS 2:1960 rules for rounding final observed/calculated values.
• Retain the number of significant places as specified in the standard.

flowchart TD
    A[Excavation Material] --> B[Soft/Loose Soil]
    A --> C[Hard/Dense Soil]
    A --> D[Mud]
    A --> E[Soft/Disintegrated Rock]
    A --> F[Hard Rock (Blasting)]
    A --> G[Hard Rock (No Blasting)]

This classification guides excavation methods and measurement procedures per IS 1200 Part 1.

IS 1200 Part 1: General Principles of Measurement

Key Specifications:

• Measurement Units: All measurements are in the decimal system.
• Dimension Accuracy:
  • Linear dimensions measured to nearest 0.01 m
  • Areas measured to nearest 0.01 m²
  • Volumes measured to nearest 0.01 m³

Rounding Off Rules (per IS 2:1960):

• Final measured/calculated values must be rounded off following IS 2:1960.
• The number of significant figures in the rounded value should match the specified precision.

Summary Table:

Notes:

• Measurements are net (actual work done, excluding wastage).
• Fixed in position as per site conditions.
• Ensures uniformity and accuracy in measurement for billing and documentation.

flowchart LR
    A[Start Measurement] --> B{Type of Measurement}
    B -->|Linear| C[Measure to 0.01 m]
    B -->|Area| D[Calculate & round to 0.01 m²]
    B -->|Volume| E[Calculate & round to 0.01 m³]
    C --> F[Apply IS 2:1960 rounding]
    D --> F
    E --> F
    F --> G[Record final value]

This ensures consistency and compliance with IS standards in building and civil engineering works.

IS 1200 Part 1: Classification of Materials for Excavation

Soil and Rock Classification (Clause 3)

Notes:

• Cobblestone: Rounded rock fragments 80-300 mm diameter.
• Boulder: Rounded rock fragments >300 mm diameter.
• Further sub-classification may be done based on specific site conditions.

Measurement Unit for Pumping (Clause 2.7)

• Measured in KW hrs or HP hrs for all pumping stages, including intermediate stages.

Summary Diagram:

flowchart TD
    A[Materials to be Excavated] --> B[Soft/Loose Soil]
    A --> C[Hard/Dense Soil]
    A --> D[Mud]
    A --> E[Soft/Disintegrated Rock]
    A --> F[Hard Rock (Blasting Required)]
    A --> G[Hard Rock (Blasting Prohibited)]

This classification helps in estimating excavation difficulty, equipment choice, and cost.

IS 1200 (Part 1) - Method of Measurement for Excavation

1. Classification of Excavated Material (Clause 3)

• Soft/Loose Soil: Easily dug by hand tools (e.g., sand, silt, clay).
• Hard/Dense Soil: Requires picks or scarifiers (e.g., stiff clay, gravel).
• Mud: Soil-water mixture in fluid/weak state.
• Soft/Disintegrated Rock: Can be split with crowbars (e.g., laterite).
• Hard Rock (Blasting Required): Rock requiring blasting.
• Hard Rock (Blasting Prohibited): Hard rock excavated by chiselling, wedging.

2. Measurement Methods (Clause 4.2)

• Uniform Ground: Measure trenches/borrow pits using average depth from "dead men" or "tell-tales."
• Non-uniform Ground: Take levels before start, after clearance, and after completion; compute volume from level differences.
• Mixed Materials:
  • Measure total volume by above methods.
  • Separate hard rock by stacking and apply void deduction (usually 40-50% voids).
  • Deduct hard rock volume from total to get soft rock or soil volume.
• Special Cases: Use tell-tales or cross-sectional area to separate hard/dense soil from rock.

3. Special Excavations (Clause 4.2.5)

• Measure authorized or actual quantities, whichever is less, for:
  • Work with formwork
  • Work covered by damp proofing or protective masonry
  • Trenches for post-tensioned beams
  • Special works (e.g., guniting)

4. Excavation for Trenches and Small Areas (Clause 4.8)

• Measure in cubic meters for trenches ≤1.5 m width and shafts/wells ≤10 m² plan area.

Void Deduction for Hard Rock Stacking (Typical)

Volume Calculation from Levels (Non-uniform Ground)

[ \text{Excavation Volume} = \sum \left( \frac{A_1 + A_2}{2} \times h \right) \

IS 1200 Part 1: Lead and Lift Measurement Summary

Lead (Clause 5.1 & 5.1.3)

• Definition: Horizontal distance earth is moved from excavation to deposit point.
• Measurement:
  • Divide excavation area into blocks.
  • Measure distance from center of each block to center of deposited earth (lead).
  • Use shortest practicable route, not necessarily actual route.
• Units:
  • ≤ 250 m: measured in 50 m units.
  • 250 m to 500 m: separate item.
  • 500 m to 5 km: measured in 500 m units.

  • 5 km: measured in 1 km units (≥ 0.5 km rounded up, < 0.5 km ignored).

Lift (Clause 5.2)

• Definition: Vertical height earth is lifted.
• Measurement:
  • From ground level.
  • Excavation up to 1.5 m depth included in earthwork item.
  • Extra lift measured in 1.5 m units or part thereof.
  • Obvious lifts only (lift due to slope within lead not measured except for leads ≤ 250 m).
  • When dumping beyond obstruction, lift = difference between center of gravity of excavated earth and top of obstruction.

Key Points Table

flowchart LR
    A[Excavation Area] --> B[Divide into Blocks]
    B --> C[Measure Horizontal Distance (Lead)]
    C --> D[Measure Vertical Distance (Lift)]
    D --> E[Calculate Lead & Lift in Units]

This ensures consistent measurement for earthwork cost estimation and billing.

IS 1200 Part 1: Planking and Strutting Key Points

• Measurement Basis:

  • Measured in square metres of face supported (Clause 6.1.2).
  • Grouped separately in stages of 1.5 m lift (Clause 6.1.2, 5.2).
  • Includes use and waste of timber (Clause 6.1.1).
  • Separate measurement for permanent planking/strutting left in position (Clause 6.1.4).

• Scope of Measurement:

  • Areas including raking shores (6.1.2b).
  • Shafts, wells, cesspits, manholes, etc. (6.1.2c).

• Lift Definition:

  • Lift measured from ground level.
  • Excavation up to 1.5 m depth included in earthwork; extra lift measured in 1.5 m increments (Clause 5.2).
  • Lift accounts for vertical difference between center of gravity of excavated earth and dumping point.

Typical Measurement Formula for Planking & Strutting Area:

[ \text{Area (m}^2) = \text{Length of face supported (m)} \times \text{Height of support (m)} ]

• Height is taken in multiples of 1.5 m lifts.

Summary Table for Lift Stages

flowchart TD
    A[Excavation] --> B[Measure Face Supported]
    B --> C{Height of Support}
    C -->|≤1.5 m| D[Included in Earthwork]
    C -->|>1.5 m| E[Measure Extra Lift in 1.5 m Stages]
    E --> F[Calculate Area = Length × Height]
    F --> G[Include Timber Use & Waste]
    G --> H[Separate Permanent Planking]

Note: Always include fixing and removal of timber in descriptions (Clause 6.1

IS 1200 Part 1: Removal of Vegetation and Trees

Key Specifications & Measurement Clauses

• Clause 7.1: Clearing Shrubs, Brushwood, Small Trees

  • Trees with girth ≤ 300 mm (measured at 1 m above ground)
  • Measurement unit: Square metres (m²)
  • Includes removal and disposal

• Clause 7.2: Cutting Hedges and Fences

  • Measurement unit: Running metres (m)
  • Includes removal and disposal

• Clause 7.4: Digging out Roots

  • Measured separately, includes stacking and disposal

• Clause 6.1.4: Planking and Strutting

  • If left permanently, measured separately

Measurement Summary Table

Practical Notes

• Girth Measurement: Always at 1 m above ground level.
• Disposal: Included in all clearing/removal measurements.
• Permanent Supports: Planking/strutting measured separately if retained.

flowchart TD
    A[Vegetation Removal] --> B[Small Trees ≤ 300mm girth]
    A --> C[Hedges & Fences]
    A --> D[Roots Digging]
    B --> E[Measure in m²]
    C --> F[Measure in running metres]
    D --> G[Measured separately]
    E & F & G --> H[Includes removal & disposal]

This concise summary aligns with IS 1200 Part 1 clauses for vegetation and tree removal.

IS 1200 (Part 1) – Surface Excavation & Surface Dressing

Surface Dressing (Clause 4.4)

• Definition: Trimming natural ground or excavated/fill surfaces to remove vegetation or small irregularities ≤ 150 mm deep.
• Measurement: Area in square metres (m²).

Surface Excavation (Clause 4.6)

• Definition: Excavation exceeding 1.5 m width & 10 m² plan area but ≤ 300 mm depth.
• Measurement: Area in square metres (m²).

Material Classification (Clause 3)

Measurement Notes (Clause 4.2.2)

• Dressing/trimming sides and levelling/ramming bottoms are included with excavation items except rough excavation.

Summary Table of Surface Excavation & Dressing

If pumping/dewatering is needed (Clause 2.7), measure separately in KWhr or HPh.

flowchart TD
    A[Surface Preparation]
    A --> B[Surface Dressing]
    B -->|Trim ≤150 mm| C[Measure in m²]
    A --> D[Surface Excavation]
    D -->|Depth ≤300 mm &

IS 1200 Part 1 – Filling and Embankments: Key Points

Measurement & Specifications (Clauses 4.11, 4.3.1, 4.12)

• Volume Measurement:

  • Measured in cubic metres (m³) including slopes.
  • Levels recorded at intervals (e.g., every 1.5 m height stages).
  • For embankments, measure from original ground level to the final compacted level.

• Layering & Compaction:

  • Fill deposited in layers, max thickness: 200 mm (Clause 4.12).
  • Each layer must be watered, rammed, and levelled properly.

• Consolidation:

  • Method of consolidation (e.g., mechanical compaction) must be described.
  • For special soils (e.g., marine clay), allowance for settlement/change in levels due to load must be specified.

• Calculations:

  • Compute fill quantity by comparing original ground levels before work and final compacted levels after filling.

Typical Formula for Fill Volume:

[ V = \sum \left( \frac{A_1 + A_2}{2} \times h \right) ]

Where:

• (A_1, A_2) = cross-sectional areas at two consecutive sections
• (h) = distance between sections

Summary Table:

flowchart TD
    A[Original Ground Level] --> B[Layer-wise Filling (≤200mm)]
    B --> C[Watering & Compaction]
    C --> D[Level Measurement at 1.5m Intervals]
    D --> E[Volume Calculation]
    E --> F[Account for Soil Settlement if Needed]

This ensures accurate volume estimation and quality control for embankments and filling works per IS 1200 Part 1.

IS 1200 Part 1: Measurement of Excavation for Pipes, Cables, and Foundations

Key Specifications & Formulas

• Excavation Width & Volume:

  • Trenches ≤ 1.5 m wide and shafts ≤ 10 m² plan area measured in cubic meters.
  • For trenches > 1 m deep, add 50 mm per meter depth on each side to the specified width:

  [ \text{Effective Width} = \text{Specified Width} + 2 \times (0.05 \times \text{Depth}) ]

• Measurement Basis:

  • Use cross-sections at suitable intervals for volume calculation.
  • Measure quantities based on authorized width or actual excavation width, whichever is less.

• Material Classification (for excavation difficulty and method):

  • Soft/Loose Soil: Easily dug with pick/shovel (e.g., sand, silt, clay).
  • Hard/Dense Soil: Requires close application of picks (e.g., stiff clay, gravel).
  • Mud: Soil-water mixture, fluid or weak solid.
  • Soft Rock: Can be split with crowbars (e.g., laterite).
  • Hard Rock: Requires blasting.
  • Hard Rock (Blasting Prohibited): Excavated by chiselling or wedging.

Practical Measurement Steps

1. Determine authorized width (W).

2. For depth (D) > 1 m, calculate effective width:

   [ W_{\text{eff}} = W + 2 \times 0.05 \times D ]

3. Take cross-sectional area at intervals, multiply by length to get volume.

4. Measure volume in cubic meters.

flowchart TD
    A[Start: Excavation for Pipes/Cables/Foundation] --> B{Width ≤ 1.5 m?}
    B -- Yes --> C[Measure volume in m³]
    B -- No --> D[Use authorized width and cross-sections]
    D --> E{Depth > 1 m?}
    E -- Yes --> F[Add 50 mm/m depth each side to width]
    E -- No --> G[Use specified width]
    F & G --> H[Calculate volume using cross-sections]
    H --> I

IS 1200 Part 1: Booking of Dimensions and Rounding Off

Key Points from Clauses:

• Clause 2.2 (Booking of Dimensions):

  • Dimensions are recorded in order: Length → Breadth/Width → Height/Depth/Thickness.

• Clause 2.3 (Measurements):

  • Length dimensions: Rounded to nearest 0.01 m.
  • Areas: Rounded to nearest 0.01 m².
  • Volumes: Rounded to nearest 0.01 m³.

• Rounding Off (per IS 2:1960):

  • Final measured/calculated values are rounded according to IS 2:1960 rules.
  • Number of significant figures retained equals that of the specified value in the standard.

• Example for Filling under Floors (Clause 4.12):

  • Measured in cubic metres.
  • Layers not exceeding 200 mm thickness.
  • Includes watering, ramming, and levelling.

Summary Table for Booking & Rounding

Rounding Off Rules (IS 2:1960 Summary)

• If digit after last significant figure < 5 → round down.
• If digit = 5 and followed by non-zero digits → round up.
• If digit = 5 and no following digits → round to nearest even digit.

flowchart LR
    A[Start Booking Dimensions] --> B[Measure Length (nearest 0.01 m)]
    B --> C[Measure Breadth/Width (nearest 0.01 m)]
    C --> D[Measure Height/Depth/Thickness (nearest 0.01 m)]
    D --> E[Calculate Area (round to 0.01 m

IS 1200 Part 1: Special Cases and Notes (Summary)

• Authorized Working Space (Clause 4.2.5.1):
  When not specifically defined, the authorized working space shall be decided case-by-case, ensuring safe and practical working conditions.

• Measurement Rounding (General Rule):
  Final measurement values must be rounded per IS 2:1960 rules, retaining the same number of significant figures as specified in the standard.

• Measurement in Special Cases (Clause 4.2.5):
  For works involving formwork, damp proof coverings, protective masonry, post-tensioned concrete beams, guniting, or where workers operate externally, the lesser of authorized quantities or actual excavation shall be measured.

Key Points Table

Rounding Off Rule (IS 2:1960)

• If the specified value has n significant figures, round the measured/calculated value to n significant figures.
• Use standard rounding rules (≥5 rounds up).

flowchart TD
    A[Start: Measurement] --> B{Is work special case?}
    B -- Yes --> C[Measure lesser of authorized or actual excavation]
    B -- No --> D[Measure actual excavation]
    C --> E[Round off per IS 2:1960]
    D --> E
    E --> F[Final recorded value]

This ensures accurate and consistent measurement for special construction scenarios.