Code of practice for a sampling of soils by thin wall sampler with stationary piston

IS 10108 - Scope: Key Specifications & Tables

Scope: This standard covers thin-walled tube sampling of soils, defining sampler dimensions, sampling procedures, and reporting formats.

1. Sampling Tube Dimensions (Clause 3.2.2 & Fig. 3)

Note: For stiff clays or silty soils, increase tube thickness suitably to reduce sample disturbance.

2. Reporting Requirements (Clause 5.1)

All field data must include:

• Job ID, date, boring number & coordinates
• Surface elevation, drilling method
• Sample number, depth, sampler type & size
• Method of sampler advancement, penetration, recovery ratio
• Water table depth, artesian head, casing details
• Soil description & layer thickness
• Weather and other remarks

Use the proforma recommended in IS 2132-1972 Appendix A.

Summary Diagram: Sampling Tube Components

graph LR
A[Sampling Tube] --> B(Diameter D)
A --> C(Inside Diameter D1)
A --> D(Thickness)
A --> E(Cutting Edge Angle α)
A --> F(Length L)

This standard ensures consistent soil sampling quality for geotechnical investigations.

IS 10108: Key Definitions & Specifications Summary

1. Definitions:

• As per Clause 2.1, definitions follow IS 2809-1972 (Glossary of soil engineering terms).
• Rounding rules for numerical values apply as revised.

2. Sampling Tube Dimensions (Clause 3.2.2 & Fig. 3):

• Note: For stiff clays or silty soils, tube thickness may be increased to reduce sample disturbance.

3. Sampling Report Requirements (Clause 5.1):

• Job ID, date, boring number & coordinates
• Surface elevation, drilling method
• Sample number, depth, penetration details, recovery ratio
• Sampler type & size, water table depth
• Soil description, layer thickness, weather, remarks
• Use proforma per IS 2132-1972 Appendix A.

flowchart TD
    A[Start Sampling] --> B[Select Sampling Tube]
    B --> C{Tube Diameter?}
    C -->|74 mm| D[Use 74 mm specs]
    C -->|50 mm| E[Use 50 mm specs]
    D --> F[Record Sampling Data]
    E --> F
    F --> G[Prepare Report per Clause 5.1]
    G --> H[Complete]

IS 10108: Equipment and Apparatus Key Specifications

1. Sampling Tube Dimensions (Clause 3.2.2, Table 3.2)

2. Apparatus to Push Sampling Tube (Clause 3.5)

• Must provide smooth, shock-free force.
• Hydraulic jack, compressed air, or mechanical jacking devices are recommended.
• Ensures efficient penetration of sampling tube into soil.

3. Data to be Recorded During Sampling (Clause 5.1)

Include:

• Job ID, dates, boring number & coordinates
• Drilling method, sample number & depth
• Sampler type & size, penetration/recovery ratio
• Water table info, casing size & depth
• Soil description, layer thickness
• Weather and other observations

Summary Diagram of Sampling Tube

graph LR
A[Sampling Tube] --> B[Cutting Edge Diameter (D)]
A --> C[Inside Diameter (D1)]
A --> D[Thickness (Steel/Brass)]
A --> E[Cutting Edge Angle (α)]
A --> F[Length (L)]

This ensures standardization and reliability in soil sampling apparatus per IS 10108.

IS 10108: Sampling Procedure Key Details

1. Sampling Tube Dimensions (Clause 3.2.2)

2. Gross Recovery Ratio (Clause 4.4.1)

[ \text{Gross Recovery Ratio} = \frac{\text{Length of sample obtained}}{\text{Depth of penetration}} \times 100% ]

• Acceptable Undisturbed Sample: Gross Recovery Ratio ≥ 95%

3. Sample Labeling (Clause 4.4.4)

Mark on sampling tube:

• Project name
• Boring number & sample number
• Depth of sampling
• Date of sampling
• Top and/or bottom end of sample

Refer IS 1892-1980 for tabular formats.

flowchart TD
    A[Start Sampling] --> B[Use Sampling Tube (per dimensions)]
    B --> C[Insert tube to depth]
    C --> D[Extract sample]
    D --> E[Measure sample length]
    E --> F[Calculate Gross Recovery Ratio]
    F -->|≥95%| G[Accept Sample]
    F -->|<95%| H[Reject Sample]
    G --> I[Label Sample Tube]
    I --> J[Store/Transport Sample]

This ensures proper sampling quality and traceability as per IS 10108.

IS 10108: Recording and Reporting Key Points

1. Sample Identification (Clause 4.4.4)

Record on sampling tube exterior:

• Project name
• Boring number & sample number
• Sampling depth
• Sampling date
• Top/bottom end of sample

Preferably use a table format as per IS 1892-1980.

2. Gross Recovery Ratio (Clause 4.4.1)

Calculate after sample removal:

[ \text{Gross Recovery Ratio (GRR)} = \frac{\text{Length of sample obtained}}{\text{Depth of penetration}} \times 100% ]

• Acceptable undisturbed sample: GRR ≥ 95%

3. Field Data to Record (Clause 5.1)

Use proforma as per IS 2132-1972 Appendix A.

Summary Table for Recording Sample Data

IS 10108: Precautions and Sample Handling Key Points

• Transportation (Clause 4.5.1):
  Avoid impact and sudden temperature changes to prevent altering sample properties.

• On-site Storage (Clause 4.4.5):
  Protect samples from direct sunlight and extreme temperature fluctuations during temporary storage.

• Laboratory Storage (Clause 4.5.2):

  • Seal both ends of samples tightly.
  • Group samples by lot with clear identification.
  • Store in a dark, humid environment to maintain integrity.

• Sample Extraction (Clause 4.6):
  Follow standardized extraction procedures to avoid contamination or damage.

Additional Best Practices (Engineering Knowledge)

flowchart TD
    A[Sample Collection] --> B[Transportation]
    B --> C{Avoid Impact & Temp Change}
    C --> D[On-site Storage]
    D --> E{Avoid Sunlight & Temp Fluctuations}
    E --> F[Laboratory Storage]
    F --> G{Seal Ends & Store Dark/Humid}
    G --> H[Sample Extraction]

Summary: Proper sealing, controlled environment, and gentle handling ensure sample integrity per IS 10108.

IS 10108 – Transportation and Storage of Samples: Key Points

Transportation (Clause 4.5 & 4.5.1)

• Avoid impact: Handle samples gently to prevent mechanical shocks.
• Temperature control: Prevent serious temperature changes during transit.
• Packaging: Use protective packaging to minimize vibration and impact.

Storage (Clause 4.4 & 4.4.5)

• Temporary storage: Avoid direct sunlight or extreme temperature variations.
• Environment: Store samples in shaded, dry, and stable temperature conditions.
• Handling: Minimize handling to reduce risk of damage or contamination.

Summary Table

Practical Tips:

• Use insulated containers if temperature-sensitive.
• Cushion samples with foam or padding.
• Avoid stacking heavy loads on samples.

flowchart LR
    A[Sample Preparation] --> B[Packaging]
    B --> C[Transportation]
    C --> D[Temporary Storage]
    D --> E[Testing]
    style B fill:#f9f,stroke:#333,stroke-width:2px
    style C fill:#bbf,stroke:#333,stroke-width:2px
    style D fill:#fbf,stroke:#333,stroke-width:2px

This ensures sample integrity per IS 10108 guidelines.

IS 10108: Key Points on Field Observations

1. Water Table Observations (Clause 4.3)

• Record groundwater level, elevations of water loss during drilling, and artesian pressures.
• Measure water levels:
  • Sandy soils: Immediately as casing is pulled and after 30 min.
  • Silty soils: After 24 hours.
  • Clay soils: No accurate level unless pervious seams; record 24-hour level regardless.
• When drilling mud is used, use perforated casing and bail out mud before measuring water levels at 30 min and 24 h intervals.

2. Sample Tube Markings (Clause 4.4.4)

Mark outside of sampling tube with:

• Project name
• Boring and sample number
• Sampling depth
• Sampling date
• Top and/or bottom of sample

Refer IS 1892-1980 for tabular format.

3. Field Data Recording (Clause 5.1)

Record on field logs:

• Job ID, boring dates, boring number & coordinates
• Surface elevation, drilling method
• Sample number, depth, sampler type, penetration, recovery ratio
• Water surface depth, artesian head, reading times
• Casing size, cased hole depth
• Soil description, layer thickness
• Weather and remarks

Use proforma as per IS 2132-1972 Appendix A.

Summary Table for Water Level Measurement Timing

flowchart TD
    A[Start Drilling] --> B[Record Water Table Info]
    B --> C{Soil Type?}
    C -->|Sandy| D[Measure water level as casing pulled]
    C -->|Sandy| E[Measure water level after 30 min]
    C -->|Silty| F[Measure water level after 24 hrs]
    C -->|Clay| G[Measure water level after 24 hrs if pervious seams]
    D --> H[Record all observations in field log]
    E --> H
    F --> H
    G --> H

**

IS 10108: Maintenance and Inspection of Sampler

Key Inspection & Maintenance Points (Clause 4.2.1)

• Inspect before use for:
  • Loosening of components
  • Functioning of piston rod lock device
  • Distortion of sampling tubes
• Repair/replace damaged parts before use.
• Measure outside diameter of sampling tube at 30, 40, and 80 cm from the edge.
• Check max/min inside diameters of the tube.

Sampling Tube Specifications (Clause 3.2.2)

Operational Notes

• Disembarkment (Clause 4.2.8): Loosen piston ventilation before extraction to avoid sample disturbance.
• Core Catcher: Use spring leaf core catcher in loose sands below water table to prevent sample loss.
• Hydraulic Operation: Recommended for thin-walled samplers to minimize disturbance and overdriving (see Fig. 8).

Handling Tips (Clause 4.2.7)

• Rotate sampler bottom gently before lifting.
• Wait 10-20 minutes after driving before withdrawal to allow adhesion/friction development.

flowchart TD
    A[Inspect Sampler] --> B{Check Components}
    B -->|Loose Parts| C[Repair/

IS 10108 Annexures and Appendices Key Points

• Appendix A of IS:2132-1972 provides a recommended proforma for recording field data during boring and sampling, including:

  Data Item	Description
  Job Identification	Project name or code
  Date of Boring	Start and finish dates
  Boring Number & Coordinates	Location details if available
  Surface Elevation	Ground level data if available
  Drilling Method	Type of drilling technique used
  Sample Number & Depth	Identification and depth of each sample
  Sampler Details	Type, size, method of advancement, penetration, recovery ratio, pressure
  Water Table Data	Depth to water surface, artesian head, time of readings
  Casing Details	Size and depth of cased hole
  Soil Description	Visual examination and layer thickness
  Weather Conditions	During sampling
  Other Observations	Remarks or unusual findings

• Marking on Sampling Tubes (Clause 4.4.4):

  • Project name, boring & sample number, depth, date, and sample ends should be recorded on the tube.

• Refer to IS:1892-1980 for standardized tables for marking samples.

Summary Table for Field Data Recording (Example Format)