IS 2911:2021 Part 4 is the Indian Standard (BIS) for design and construction of pile foundations - load test on piles. This standard provides the methodology and criteria for conducting initial and routine load tests on pile foundations. It details the setup, procedure, and safe load evaluation criteria for vertical compression, lateral load, and pull-out (uplift) tests to validate foundation design and execution.
Specifies the procedures for conducting various types of load tests on piles to determine their carrying capacity.
Key values for pile load testing including test loads, acceptance criteria for vertical, lateral, and pull-out tests, and equipment specifications.
| Reference | Value | Clause |
|---|---|---|
| Initial Test Piles (min)— For projects with >200 piles, min 2 tests are required. | 0.5% of total piles, min 1 | Cl. 5.1.1 |
| Routine Test Piles (min)— Percentage depends on pile type and strata variability. | 0.5% to 2% of total piles | Cl. 5.1.2 |
| Min Concrete Age for Testing— Or when concrete achieves its specified 28-day strength. | 28 days | Cl. 5.3 |
| Hydraulic Jack Capacity | ≥ 1.25 × Max Test Load | Cl. 6.2.1 |
| Dial Gauge Least Count— For measuring pile movement (settlement/deflection). | 0.01 mm | Cl. 6.2.2 |
| Datum Bar Support Distance— D is pile dia. Use the greater value from test pile edge. | ≥ 3D or 2.5 m | Cl. 6.2.3 |
| Initial Test - Max Test Load— Or load causing settlement of 10% of pile diameter. | 2.5 × Safe Load | Cl. 7.1.1 |
| Initial Test - Load Increment | 20% of Safe Load | Cl. 7.1.2 |
| Initial Test - Holding Time (Final Load)— Or until settlement rate is < 0.1 mm/30 min. | 24 hours | Cl. 7.1.2 |
| Initial Test - Acceptance (Settlement @ 1.5x Safe Load)— For single piles. | ≤ 12 mm | Cl. 7.1.5.1 a) |
| Initial Test - Acceptance (Net Settlement)— After removing the test load. | ≤ 6 mm | Cl. 7.1.5.1 b) |
| Initial Test - Acceptance (Settlement @ Safe Load)— Alternate criterion from load-settlement curve. | ≤ 6 mm | Cl. 7.1.5.2 |
| Routine Test - Max Test Load | 1.5 × Safe Load | Cl. 7.2.1 |
| Routine Test - Holding Time (Final Load)— Or until settlement rate is < 0.1 mm/30 min. | 12 hours | Cl. 7.2.1 |
| Routine Test - Acceptance (Total Settlement)— At 1.5 times the safe load. | ≤ 12 mm | Cl. 7.2.2 |
| Lateral Test - Max Test Load | 2 × Safe Lateral Load | Cl. 8.1 |
| Lateral Test - Acceptance (Deflection @ Safe Load)— Or as specified in the design. | ≤ 5 mm | Cl. 8.2.1 a) |
| Lateral Test - Acceptance (Net Deflection)— After removing the test load. | ≤ 20% of total deflection | Cl. 8.2.1 b) |
| Pull-out Test - Max Test Load | 2 × Safe Uplift Load | Cl. 9.1 |
| Pull-out Test - Acceptance (Displacement @ Safe Load)— Or as specified in the design. | ≤ 5 mm | Cl. 9.2.1 a) |
| Pull-out Test - Acceptance (Net Displacement)— After removing the test load. | ≤ 2 mm | Cl. 9.2.1 b) |
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Under-ream / Bell Diameter Ratio (Du/D) | Typically 2.5. Can be up to 3.0 in special cases with permission. | No prescribed ratio; commonly up to 3.0 times shaft diameter, based on design requirements. | ACI 336.3R-14 |
| Vertical Spacing Between Bulbs | 1.25 to 1.5 times the under-ream diameter (Du). | Not specified, as multi-bell piers are uncommon. Design would be based on shear analysis between bells. | ACI 336.3R-14 |
| Factor of Safety on Bearing Capacity (from soil properties) | 2.5 to 3.0 | Generally 3.0 for end bearing and 2.0 to 3.0 for side resistance. | ACI 336.3R-14 |
| Factor of Safety on Bearing Capacity (from load test) | 2.5 for initial test; 2.0 for routine test. | Typically 2.0. | ACI 336.3R-14 |
| Minimum Longitudinal Reinforcement | 0.4% of pile stem cross-sectional area. | Typically 0.5% to 1.0% of the gross cross-sectional area (references ACI 318). | ACI 336.3R-14 / ACI 318 |
| Bell Slope Angle (from horizontal) | Not explicitly defined; formed by the cutting tool geometry. | Recommended to be at least 45° to 60° for stability, depending on soil type. | ACI 336.3R-14 |
| Concrete Slump (for Tremie/Underwater Placement) | 150 - 200 mm | 175 - 225 mm (7 - 9 inches) | ACI 336.1-19 |