Anchor Pile Load Test
ANCHOR PILE LOAD TEST AS PER IS 2911 PART-4 2013
In pile load testing using the anchor method, a test pile is subjected to a load, and the reaction force is transferred to anchor piles or rock anchors placed around it. This method is often used when a large reaction force is needed, or when other methods like kentledge are impractical. The test involves applying a compressive load to the pile through hydraulic jacks, with the load transmitted to the anchor piles which go into tension during compression tests.
Anchor Test Methods
Anchor Test can be performed by 2 arrangement procedure
By Girder: In this procedure 15.2 mm/12.7 mm Ht strands will cut to required length as per the design provide by client then make the Ht strands profiling and after that anchor bores are done horizontally to the pile as per IS 2911 Part IV.
By Crown: In this procedure 15.2 mm/12.7 mm Ht strands will cut to required length as per the design provide by client then make the Ht strands profiling and after that anchor bores are done Surrounded to the pile as per IS 2911 Part IV.
Step 1: Installation and Setup
- Test Pile: A pile is installed in the ground where its load-carrying capacity is being tested.
- Anchor Piles/Rock Anchors: Anchor piles or rock anchors are installed around the test pile, typically at a distance of three times the pile diameter to minimize interference.
- Reaction Beam: A reaction beam is placed on top of the anchor piles, providing a platform for the hydraulic jacks.
- Hydraulic Jacks: Hydraulic jacks are positioned to apply compressive load to the test pile, while the anchor piles resist the force.
Step 2: Loading and Measurement
- Load Application: Loads are applied to the test pile in stages, with the hydraulic jacks gradually increasing the pressure.
- Reaction Force: The load applied to the test pile is resisted by the anchor piles, which go into tension.
- Measurements: Dial gauges or other instruments are used to monitor the movement of the test pile as the load is applied.
- Load-Settlement Curve: A load-settlement curve is typically plotted to analyze the pile's behavior and determine its load-carrying capacity.
Step 3: Analysis and Interpretation
- Ultimate Load: The ultimate load is the maximum load the pile can withstand before significant settlement or failure. The load-settlement curve provides insights into the pile's behavior under load, including its stiffness, resistance, and potential for settlement.
Advantages of the Anchor Method
- Large Test Loads: The anchor method can handle larger test loads compared to methods like kentledge, especially when rock anchors are used.
- Reduced Footprint: The anchor arrangement often requires a smaller footprint than kentledge, making it suitable for sites with limited space.
- Flexibility: The method can be used for both compression and tension pile load tests.