Geotechnical Engineering Laboratory 1

1. 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

2. 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.

3. 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

4. II. MATERIALS AND METHODOLOGY
2.1 Materials
a.) Cling Wrap
b.) Zip lock
Plastic bags
c.) Plastic Storage Box
d.) Steel Tube

5. e.) Shovel
f.) Knife
g.) Crowbar
h.) Pick and Mattock

6. 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)

7. 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.

8. 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