Code of practice for a sampling of soils by thin wall sampler with stationary piston
1982 Edition

Overview of Application and Specifications

Scope: This document establishes procedures for thin-walled tube soil sampling, detailing sampler dimensions, sampling steps, and data reporting formats.

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

Note: For stiff clay or silty soils, increase thickness of the tube to lessen sample disturbance.

2. Data Reporting Requirements (Clause 5.1)

Field records should include:

• Project identification, date, borehole number and location
• Surface elevation and drilling method used
• Sample identification, depth, sampler type and dimensions
• Advancement method, penetration depth, and recovery percentage
• Groundwater table depth, artesian pressure, and casing details
• Soil description and thickness of layers
• Weather conditions and additional remarks

Utilize the template recommended in IS 2132-1972 Appendix A.

Diagram: Sampling Tube Components

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

This ensures uniformity in soil sampling quality for geotechnical purposes.

Essential Definitions and Specifications in IS 10108

1. Definitions:

• As per Clause 2.1, terms are consistent with IS 2809-1972's glossary of soil engineering.
• Numeric values are rounded according to updated rules.

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

• Note: Tube thickness may be increased for stiff clays or silty soils to minimize disturbance.

3. Reporting Format (Clause 5.1):

• Include project ID, dates, borehole number, location
• Surface elevation, drilling technique
• Sample ID, depth, penetration details, recovery ratios
• Sampler type and size, groundwater data
• Soil description and thickness
• Weather conditions and comments
• Follow format as per IS 2132-1972 Appendix A.

flowchart TD
    A[Begin Sampling] --> B[Select Tube Diameter]
    B --> C{Tube Size?}
    C -->|74 mm| D[Apply 74 mm Specifications]
    C -->|50 mm| E[Apply 50 mm Specifications]
    D --> F[Record Sampling Details]
    E --> F
    F --> G[Compile Report per Clause 5.1]
    G --> H[Process Complete]

IS 10108 Equipment Details and Requirements

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

2. Sampling Tube Advancement Apparatus (Clause 3.5)

• Must deliver smooth, continuous, and shock-free force.
• Recommended devices include hydraulic jacks, compressed air systems, or mechanical jacks.
• These ensure effective penetration without sample disruption.

3. Data to Record (Clause 5.1)

Include details such as:

• Project identification, dates, borehole numbers, and coordinates
• Drilling method, sample number, depth
• Sampler type, size, penetration method, recovery ratio
• Groundwater data, casing dimensions and depth
• Soil descriptions and layer thicknesses
• Weather and remarks

Sampling Tube Component Diagram

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

This ensures standardized and reliable sampling equipment as per the standard.

IS 10108 Sampling Methodology Overview

1. Dimensions of Sampling Tube (Clause 3.2.2)

2. Calculation of Gross Recovery Ratio (Clause 4.4.1)

[ \text{Gross Recovery Ratio} = \frac{\text{Sample Length Obtained}}{\text{Penetration Depth}} \times 100% ]

• A gross recovery ratio equal to or exceeding 95% indicates an undisturbed sample.

3. Labeling Samples (Clause 4.4.4)

Mark the sampling tube clearly with:

• Project name
• Borehole and sample numbers
• Sampling depth
• Date of sampling
• Indicate top and bottom ends of the sample

Refer to IS 1892-1980 for standardized label formats.

flowchart TD
    A[Begin Sampling] --> B[Use Sampling Tube per Specs]
    B --> C[Insert Tube to Desired Depth]
    C --> D[Retrieve Sample]
    D --> E[Measure Sample Length]
    E --> F[Compute Gross Recovery Ratio]
    F -->|≥95%| G[Accept Sample]
    F -->|<95%| H[Reject or Resample]
    G --> I[Label Sample Tube]
    I --> J[Store or Transport Sample]

This procedure ensures high-quality sampling and proper tracking as mandated by IS 10108.

IS 10108 Guidelines for Recording and Reporting

1. Sample Identification (Clause 4.4.4)

Mark on the sample tube:

• Project name
• Borehole and sample identifiers
• Sampling depth
• Date of collection
• Indicate top and/or bottom of sample

Use table formats as suggested in IS 1892-1980.

2. Gross Recovery Ratio Calculation (Clause 4.4.1)

Calculate following sample extraction:

[ \text{GRR} = \frac{\text{Sample Length}}{\text{Penetration Depth}} \times 100% ]

• A value of 95% or higher denotes an acceptable undisturbed sample.

3. Field Data Recording (Clause 5.1)

Use the proforma as per IS 2132-1972 Appendix A.

Sample Data Recording Table

IS 10108: Guidelines for Sample Handling and Precautions

• During Transportation (Clause 4.5.1):

  • Prevent mechanical shocks and impacts that could alter sample properties.
  • Avoid abrupt temperature variations.

• On-Site Storage (Clause 4.4.5):

  • Store samples away from direct sunlight and extreme heat or cold.

• Laboratory Storage (Clause 4.5.2):

  • Seal both ends of the sample tubes securely.
  • Organize samples in lots with clear labeling.
  • Maintain storage in dark, humid conditions to preserve moisture.

• Sample Extraction (Clause 4.6):

  • Follow standardized extraction methods to avoid damaging or contaminating samples.

Recommended Best Practices

flowchart TD
    A[Collect Sample] --> B[Transport Carefully]
    B --> C{Avoid Impact & Temp Shocks}
    C --> D[Store On-site in Shade]
    D --> E{Avoid Sunlight & Temp Fluctuations}
    E --> F[Laboratory Storage]
    F --> G{Seal Ends & Maintain Dark, Humid Environment}
    G --> H[Sample Extraction]

Summary: Proper sealing, controlled environmental conditions, and gentle handling are essential to maintain sample integrity.

IS 10108: Key Recommendations for Transporting and Storing Soil Samples

Transportation (Clauses 4.5 & 4.5.1)

• Handle samples gently to avoid mechanical shocks.
• Prevent significant temperature fluctuations during transit.
• Use protective packaging to reduce vibration and impact.

Storage (Clauses 4.4 & 4.4.5)

• Avoid direct sunlight and extreme temperature changes during temporary storage.
• Maintain storage in shaded, dry areas with stable temperatures.
• Minimize handling to reduce risk of damage or contamination.

Summary Table

Practical Advice:

• Utilize insulated containers for temperature-sensitive samples.
• Employ foam or padding to cushion samples.
• Avoid stacking heavy items on top of samples.

flowchart LR
    A[Prepare Sample] --> B[Package Securely]
    B --> C[Transport Carefully]
    C --> D[Temporary On-site Storage]
    D --> E[Laboratory 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

These steps help maintain sample integrity following IS 10108 protocols.

IS 10108: Important Aspects of Field Observations

1. Groundwater Level Recording (Clause 4.3)

• Document groundwater levels, water loss elevations during drilling, and artesian pressures.
• Measurement timings:
  • Sandy soils: Record immediately after casing removal and again after 30 minutes.
  • Silty soils: Measure after 24 hours.
  • Clay soils: Accurate water level measurement is usually not possible unless pervious layers exist; still record 24-hour level.
• When drilling mud is used, employ perforated casing and remove mud before measuring water levels at 30 minutes and 24 hours.

2. Marking Sampling Tubes (Clause 4.4.4)

• Indicate project name, borehole and sample numbers, sampling depth, date, and sample ends clearly.
• Follow IS 1892-1980 for standardized labeling.

3. Recording Field Data (Clause 5.1)

Log details include:

• Job ID, borehole dates, number, and location
• Surface elevation, drilling technique
• Sample number, depth, sampler details, penetration and recovery ratios
• Groundwater levels, artesian head, timing of readings
• Casing size and depth
• Soil description, layer thickness
• Weather conditions and remarks

Use IS 2132-1972 Appendix A format.

Timing for Water Level Measurements

flowchart TD
    A[Begin Drilling] --> B[Record Water Table Data]
    B --> C{Soil Type}
    C -->|Sandy| D[Measure Immediately]
    C -->|Sandy| E[Measure After 30 Minutes]
    C -->|Silty| F[Measure After 24 Hours]
    C -->|Clay| G[Measure After 24 Hours if Applicable]
    D --> H[Log All Observations]
    E --> H
    F --> H
    G --> H

IS 10108: Guidelines for Sampler Maintenance and Inspection

Inspection and Maintenance (Clause 4.2.1)

• Prior to use, check for:
  • Loose components
  • Proper operation of piston rod locking
  • Any deformation or damage to sampling tubes
• Repair or replace faulty parts before deployment.
• Measure outer diameter of sampling tube at 30, 40, and 80 cm from the edge.
• Verify maximum and minimum inner diameters for compliance.

Sampling Tube Specifications (Clause 3.2.2)

Operational Recommendations

• During extraction, loosen piston vent to avoid disturbing the sample (Clause 4.2.8).
• Use spring-leaf core catchers in loose sand zones beneath the water table to prevent sample loss.
• Hydraulic jacking is advised to reduce disturbance and prevent overdriving (see Fig. 8).

Handling Procedures (Clause 4.2.7)

• Rotate sampler base gently before lifting.
• Allow 10 to 20 minutes after penetration before withdrawal to allow friction and adhesion to develop.

flowchart TD
    A[Inspect Sampler] --> B{Check for Loose Parts}
    B -->|Yes| C[Repair or Replace]
    B -->|No| D[Measure Tube Dimensions]
    D --> E[Confirm Compliance]
    E --> F[Prepare for Sampling]

IS 10108 Annexures and Appendices Overview

• Appendix A of IS 2132-1972 provides a recommended format for recording field sampling data including:

  Data Item	Description
  Project Identifier	Name or code for the project
  Boring Dates	Start and end dates of boring
  Borehole Number & Location	Coordinates and borehole identification
  Surface Elevation	Ground level data if applicable
  Drilling Method	Type of drilling technique used
  Sample Number & Depth	Identification and depth of each sample
  Sampler Information	Type, size, advancement method, penetration, recovery ratio, pressure
  Groundwater Data	Water table depth, artesian pressure, reading times
  Casing Details	Size and depth of casing
  Soil Description	Visual assessment and layer thickness
  Weather Conditions	Conditions during sampling
  Additional Observations	Remarks or unusual events

• Sample Marking (Clause 4.4.4):

  • Record project name, borehole and sample numbers, sampling depth, date, and sample ends on the tube.

• Refer to IS 1892-1980 for standard sample marking tables.

Example Field Data Recording Table