1.1 A. SOIL SAMPLING, LABELING, AND STORAGE

Laboratory testing of soils is a fundamental element of geotechnical engineering.

Experiments should be well-planned to optimize the test data. A map of the sampling location

was secured. Necessary digging and sampling tools were used on the sample location. A

minimum of one (1) kilogram disturbed soil sample at every 0.5 meters from the ground level

was taken and placed on a sealed container to prevent moisture loss. An undisturbed soil sample

at a layer with soft soil consistency was taken using a sampler having four (4) inches diameter

and a depth of 10 inches. The sampler was then sealed with packaging tape. A disturbed soil was

taken on the ground level of about 10 kilograms and placed in an appropriate container.

1.1 B. DETERMINATION OF SOIL PROFILES

This lab will help engineers evaluate the subsoil which leads to safe design of foundations.

Pictures were taken with proper measurement on every changes of soil profile from ground level

down to 1.5 meters.

1.1 C. DRY PREPERATION OF DISTURBED SOIL FOR TEST

This lab is to separate soil samples to be used for different experiments. For sampling, we

referred to the Figure of “Minimum Sample Size for Soils Containing Aggregates” and

“Minimum Particle Size and Sample Size for Soil or Soil Aggregate Samples”. The first was for

sieve size and representative portion for tests when a coarse aggregate gradation is required

while the second was for tests with specified procedures.

1.1 D. DESCRIPTION AND IDENTIFICATION OF SOILS

This lab is to describe and identify soil samples clearly and accurately since soils have

different properties governed by their physical properties. The procedure involves inspection

with a few sample tests that can be performed to provide an initial appraisal of the naturally

occurring soil in a given area.

For soil sampling, it is important to have tools and equipment for digging such as shovel,

spade and trowel for fast and efficient in digging soil. Also, a sealed and closed container is

needed to store the samples.

The samples must be labeled properly. And the storage room must not direct to sunlight to

keep the moisture of the soil.

As we made an excavation, we encounter different layers of the soil and how it changes its

color and textures. The top layer of the soil is highly organic because we often found worms.

3.8 CLASSIFICATION OF SOILS FOR ENGINEERING PURPOSES

To further classify the soil, we used the AASHTO and USCS charts. AASHTO assigns a

group classification and a group index to the soil. The group classification ranges from A-1 (best

soils) to A-8 (worst soils). Group index values near 0 indicate good soils, while values of 20 or

more indicate very poor soils. USCS describes the texture and grain size of a soil.

Results from USCS are Sample Hibbeler and Pytel are clayey sand while Sample Fajardo

is silky sand. Errors may occur using the said chart which comes from the liquid limit and

plasticity index. Results from AASHTO are Sample Hibbeler and Pytel are A-2-7 (1) while

Sample Fajardo is A-2-7(2).