LANIBA, Roger Jr. C. Date Conducted: June 27, 2014

CE 55A- Geotechnical Engineering I (Soil Mechanics) Lab. Date Submitted: July 02, 2014

Wednesday (10:00-1:00 P.M)

Group 6

ACTIVITY # 1

COLLECTION OF DISTURB AND UNDISTURB SOIL SAMPLE

I. INTRODUCTION

Studying the behavior of earth materials is a vast subject that includes the study of soil

properties, foundations, slopes, risk mitigation, and ground improvement methods. The

following topics will guide you through much of the terminology and theory of geotechnical

engineering and soil mechanics.

Before any construction work can start, we need to study the behavior of soils. This is

covered in soil mechanics and includes the study of mineralogy, soil composition and types, and

the shear properties of soils. Soil mechanics provides knowledge about the characteristics and

the behavior of the underlying soil, which is important in the design and construction of

structures such as bridges, buildings, highways, and dams. Soil properties, in fact, determine

the type of structure to be built.

The study of the chemical and physical properties of soil helps in managing resources

while working with a particular kind of soil. Not all soils have similar properties, and working

with them requires understanding soil properties in detail.

Understanding the chemical and physical properties of soil means understanding the

soil behavior under different temperature and pressure conditions. Soil mass is always

subjected to changing temperature and pressure forces and, depending upon the chemical and

physical properties of the soil mass, the necessary actions will be taken. For agricultural and

construction purposes, soil properties need to be studied to increase the productivity of soil

and to improve the workability of the soil mass, so knowing soil behavior inside out is very

important.

Geotechnical engineers and geologists collect soil samples to learn about the properties

of the strata below the land surface. To collect the samples, scientists often use drill rig or hand

augers and special sample collection tools to gather both disturbed and undisturbed soil

samples. The type of test that the geologist or engineer must run will dictate the sample

collection method.

In connection to this, an activity was conducted last June 27, 2014 regarding the collection of

disturb and undisturbed soil sample. This activity was made and done at the mini-forest beside

the Sunrise Residence hall.

Objectives:

To collect disturb and undisturbed soil sample

To observe its properties and difference

To observe the workability of soil mass

To understand the soil behavior under temperature and pressure

II. MATERIALS AND METHODOLOGY

2.1 Materials

a.) Cling Wrap

b.) Zip lock

Plastic bags

c.) Plastic Storage Box

d.) Steel Tube

e.) Shovel

f.) Knife

g.) Crowbar

h.) Pick and Mattock

2.2 Description of Sampling Area

The laboratory activity was conducted at the mini-forest beside the Sunrise Residence

Hall. This location is covered with grass and different kinds of trees. It is where any kind of

woody plant vegetation growing in and around human settlements. The kind of soil where it is

located is best for vegetation and production of other plants and trees. This is the location

where they can unwind and gives refreshment to the people for its green color. The presence of

trees reduces stress, and trees have long been seen to benefit the health of urban dwellers.

2.3 Soil Sampling (How to conduct the activity)

How to obtain disturb soil samples?

Obtain necessary sampling and monitoring equipment.

Decontaminate or pre-clean equipment, and ensure that it is in working order.

Look for a location where to conduct the collection of disturb and undisturbed soil

sample.

Clear the area to be sampled of any surface debris (e.g., twigs, rocks, litter).

Disturbed samples are taken from cuttings produced by the drilling process.

The soil should be dig to its desired depth, approximately 0.5 meters that is enough to

see the other portion of the soil to be observed. Use the crowbar, pick and mattock and

shovel in digging the soil.

After removing some portion of the soil, obtain first the disturb soil sample (at least 3

samples are required) and put in a zip lock plastic bags.

Use the plastic storage box for the obtained disturbs soil samples.

NOTE: Do not step on the dig portion, in order to avoid applying pressure on it.

How to obtain undisturbed soil sample?

In obtaining the undisturbed soil sample, use the steel tube (where the height is 2 times its

diameter).

Obtain at least 3 samples of undisturbed soil.

Carefully lower the tube sampler down the borehole. Gradually force the tube sampler into the

soil. Do not scrape the borehole sides. Avoid hammering the rods as the vibrations may cause

the boring walls to collapse.

Remove the tube sampler from the ground. Use the knife in removing the tube.

Use the cling wrap to cover the removed steel tube.

Use the plastic storage box for the obtained undisturbed soil samples.

III. OBSERVATION/FINDING/RECOMMENDATION

During the activity, it was observed that the activity takes time in order for it to finish. It

is better to choose a location that is far from trees in order to make the activity not time

consuming and complicated. It should be ensured that the roots are properly removed before

collecting the soil samples.

IV. REFERENCES

http://geotechengineeringsoftware.wordpress.com/2013/06/12/geotechnical-engineering-

the-difference-of-disturbed-and-undisturbed-soil-sampling/

http://www.ehow.com/info_8747582_disturbed-vs-undisturbed-soil-sampling.html

http://www.civilengineeringterms.com/soil-mechanics-1/soil-sampling-disturbed-and-

undisturbed-soil-samples/

http://www.brighthubengineering.com/geotechnical-engineering/124477-soil-mechanics