IS 4453:1980 is the Indian Standard (BIS) for undisturbed sampling of soils. This code provides comprehensive guidelines and procedures for obtaining undisturbed soil samples from boreholes, trial pits, and excavations. It specifies sampler design criteria (such as area ratio, inside clearance, and outside clearance) to minimize mechanical disturbance, ensuring accurate laboratory assessment of soil strength and compressibility.
Lays down the procedure for obtaining undisturbed soil samples for laboratory testing purposes.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Area Ratio (Ar) | Should generally be less than 15%, ideally around 10%. | ≤ 15% for thin-walled tube samplers to achieve Sample Quality Category A. | ISO 22475-1 |
| Inside Clearance Ratio (Ci) | 1 to 3% for thin-walled open drive samplers. | 0.5% to 3% is recommended; can be higher (up to 5%) for very soft sensitive soils. | ISO 22475-1 |
| Outside Clearance Ratio (Co) | Should be small, generally between 0 and 2%. | Should be less than the Inside Clearance Ratio (Ci). Typical values are 0-3%. | ISO 22475-1 |
| Minimum Sample Diameter (for high-quality tests) | Recommends 75 mm and 100 mm sizes for laboratory testing. | ≥ 70 mm for Category A samples intended for tests like triaxial. | ISO 22475-1 |
| Standard Thin Tube OD | Specifies tubes such as 100 mm. | 3 in (76.2 mm) and 5 in (127 mm) are common standard sizes. | ASTM D1587 |
| Sample Sealing Medium | Molten wax. | Non-shrinking, flexible wax or special mechanical packers/caps. Recommends at least 25 mm (1 in) thickness of wax. | ASTM D1587 |
| Tube Material | Steel of adequate strength. | Carbon steel, stainless steel, or brass, with specified finishes (e.g., galvanized, lacquered). | ASTM D1587 |