cara SPT (Standard penetration test)

Summary

This video tutorial explains the proper technique for conducting Standard Penetration Tests (SPT) during soil drilling projects. The presenter emphasizes the importance of correct equipment setup, such as installing the split spoon and ensuring the hole is clean before performing the test. The depth and interval of the SPT are aligned with project contracts, and proper measurements and hammering techniques are discussed to ensure accurate data. Additionally, safety precautions, such as checking the integrity of threads and using the right tools, are highlighted to avoid errors in the testing process.

Takeaways

• 😀 Ensure that the hole for the SPT is clean and free from any debris before starting the test to ensure accurate results.
• 😀 Proper depth is crucial for an effective SPT. Ensure the test is conducted at the correct depth as specified in the contract, typically at intervals like 2 meters or 1.5 meters.
• 😀 The split spoon should be installed at the bottom of the pipe to act as the anchor during the test.
• 😀 Always check the cleanliness of the hole to avoid contaminating the sample and impacting the test data.
• 😀 The correct use of threads is important—avoid using defective threads (such as dol threads) to ensure safety and accuracy during the SPT.
• 😀 During the test, the hammer (62 kg) should be used properly to penetrate the soil. Monitor the number of blows to assess soil resistance.
• 😀 Mark the casing pipe every 15 cm to track penetration depth and keep accurate records of the number of blows at each depth.
• 😀 Follow the contractual intervals for testing, such as 2-meter or 1.5-meter depths, to maintain consistency and meet project requirements.
• 😀 The process involves repetitive insertion of pipes to reach the desired test depth and is done carefully to ensure precision.
• 😀 Monitoring the behavior of the soil during the test is important. If the soil isn't hard enough, the penetration may not provide accurate data.

Q & A

What is the primary topic of the video?

The video focuses on the proper procedure for conducting Standard Penetration Tests (SPT) in geotechnical drilling.

What should be checked before performing an SPT?

Before performing an SPT, the hole should be cleaned to ensure there is no dirt or debris, and the depth should be accurately measured to ensure it aligns with the required depth.

Why is it important to ensure the hole is clean before the SPT?

If the hole is not clean, the test results may be inaccurate, as the hammer could hit debris or other material that would not reflect the true soil conditions.

How should the depth of the SPT be managed during the test?

The depth should be measured precisely, ensuring that the SPT is conducted at the correct depth as specified in the contract, such as 20 meters in this case.

What is the significance of the interval when performing SPT?

The interval refers to the depth increments at which the SPT is performed. The contract specifies intervals, which could be 1.5 meters or 2 meters, and tests should be conducted at each of these intervals.

What should be done when installing the casing pipe for the SPT?

The casing pipe should be installed carefully, ensuring that the split at the bottom of the pipe is properly positioned for stability and accurate readings.

What role does the hammer play in the SPT process?

The hammer is used to drive the split spoon sampler into the soil. The number of blows it takes to drive the sampler a certain distance is used to estimate the soil's resistance and density.

What should be monitored when installing the hammer during the SPT?

It's important to monitor the installation of the hammer and ensure that the thread is in good condition. Using damaged threads can be dangerous, as the hammer may not function properly.

Why is it important to mark 15 cm increments on the casing pipe?

Marking 15 cm increments helps in measuring the penetration of the sampler. These marks are used to count the number of hammer blows and track how deep the sampler has penetrated.

What is indicated when the soil appears not to be hard after several blows?

If the soil does not show resistance after several blows, it suggests that the soil may be soft or unconsolidated, which can affect the interpretation of the SPT results.