Praktikum Geoteknik - MODUL 15 KUAT TEKAN BEBAS

Summary

This video explains Module 15, focusing on the free compression test of soil according to SNI 36-38:2012. It details the purpose of the test, which is to measure the soil's unconfined compressive strength and determine its sensitivity under external disturbances. The video introduces essential tools, including the free compression apparatus, cylinder molds, piston, calipers, scale, oil, extruder, wire saw, stopwatch, and wrench, and explains their functions. Step-by-step procedures are demonstrated, from preparing and molding soil samples to measuring dimensions, applying load, recording deformation, and repeating tests. The video provides a clear guide for conducting soil strength tests accurately and effectively.

Takeaways

• 😀 The video explains Module 15, which covers the free compression strength test of soil according to SNI 36-38:2012.
• 😀 The purpose of the test is to measure the soil's free compression strength until cracking occurs and to determine soil sensitivity.
• 😀 Soil sensitivity indicates how the soil's properties change when disturbed or subjected to external forces.
• 😀 The main tools used include a free compression testing device, cylinder mold, piston, caliper, scale, oil, extruder, wire saw, stopwatch, and wrench.
• 😀 The materials used in the test are disturbed soil and undisturbed soil samples.
• 😀 The first step is to prepare all necessary tools and materials for the test.
• 😀 Cylinder molds are oiled to facilitate soil sample removal after molding.
• 😀 Soil samples are extracted using an extruder, weighed, and measured for diameter and height with a caliper.
• 😀 Samples are placed in the free compression testing device, and deformation readings are recorded as load is applied.
• 😀 If deformation readings stop increasing, the test is halted, the sample is crushed, and the procedure is repeated for additional samples.
• 😀 The step-by-step procedure ensures accurate determination of both soil free compression strength and sensitivity.

Q & A

What is the main purpose of the free compression strength test described in the video?

The main purpose is to measure how much pressure the soil can withstand before cracking and to determine the resulting deformation. This helps in understanding the soil's sensitivity to external disturbances.

Which standard is referenced in the video for conducting the free compression strength test?

The test follows the Indonesian National Standard SNI 36-38 of the year 2012.

What is the significance of measuring soil sensitivity in this test?

Soil sensitivity indicates how the soil behaves under external disturbances or loading, helping to predict potential failures or changes in soil properties during construction or natural events.

Name the primary tools used in this practical test and their functions.

1) Free compression apparatus – tests the soil's free compression strength; 2) Cylinder mold – shapes soil samples for testing; 3) Piston – helps extract soil from the mold; 4) Vernier caliper – measures sample height and diameter; 5) Balance – measures soil weight; 6) Oil – facilitates removal of soil from molds; 7) Extruder – removes soil from sample tubes; 8) Wire saw – cuts soil samples; 9) Stopwatch – records time during the test; 10) Adjustable wrench – tightens bolts on the extruder.

What types of soil samples are mentioned for testing in this practical session?

The test uses undisturbed (intact) soil and disturbed soil samples.

What is the first step in preparing for the soil compression test?

The first step is to prepare all the necessary tools and materials for the test.

Why is oil applied to the cylinder mold in the preparation process?

Oil is applied to the cylinder mold to make it easier to remove the soil sample after it has been formed.

Describe the procedure for transferring soil from the sample tube to the cylinder mold.

First, use the extruder to push the soil out of the sample tube, tighten the bolt with an adjustable wrench, then turn the extruder's handle until the soil completely fills the cylinder mold.

How is the soil sample measured before testing on the free compression apparatus?

After removing the soil from the mold using the piston, its weight is measured using a balance, and its height and diameter are measured using a vernier caliper.

What is the procedure if the dial deformation does not increase during the test?

If the dial deformation does not increase, the experiment should be stopped, as it indicates no further deformation is occurring under the applied load.

Why might a soil sample need to be re-cast and tested again?

A soil sample is re-cast and tested again to ensure consistency and reliability of the test results, especially if initial testing shows anomalies or incomplete deformation.