Wet Preparation of Disturbed Soil Samples

Experiment No. 3 WET PREPARATION OF DISTURBED SOIL SAMPLES 1. Objective(s): The activity aims to impart an alternative method for preparation of disturbed soil samples. 2. Intended Learning Outcomes (ILOs): The students shall be able to: • prepare disturbed soil samples for future laboratory experiments. • distinguish standard practices in preparation of soil samples 3. Discussion: The method of wet preparation of soil samples is an alternative method used to prepare soil samples in various laboratory experiments such as moisture content determination, particle size analysis and in determination of Atterberg limits. For cases wherein removal of fine-grained soil that are attached to coarse particles is difficult, wet preparation is more appropriate than dry preparation. This is also applicable for coarse-grained particles of the sample are soft and pulverize readily. 4. Resources: 1. Digital Weighing Scale.

2. Oven.

3. Pans with at least 300 mm f and 75 mm deep.

4. Standard Sieves #10 and #40.

5. Filter Paper

5. Procedure: 1. Allow the soil sample recovered from the field to dry thoroughly on room temperature. Using a mortar and pestle, break up the aggregations thoroughly.

2. Select about 120 grams of the sample for the conduct of particle size analysis. For the determination of Atterberg limits, set aside the soil fraction passing Sieve No. 4 and weigh about 150 grams of the sample. Select a portion of about 50 grams for the determination of moisture content.

3. Separate the material set aside for the Particle size analysis into two portions using Sieve #10. Set aside the portion passing Sieve #10 as washing is to be performed on the portion retained

4. The portion retained is to be soaked in a pan until particle aggregations become soft. Place the Sieve #10 on a clean pan. Allow the soaked soil with water to flow to the sieve until the height of the water is about 12.7 mm above the mesh of the sieve. Crumble any lumps observed on the sieve using the thumb or the fingers. Transfer the washed material on a clean pan before placing another increment of soaked material into the sieve.

5. Dry the materials retained on Sieve #10 and add the material on Procedure no. 3. Set aside the material for use in the Particle size analysis. 6. Remove most of the water in the washings by allowing it to pass through a funnel fitted with a filter paper. Remove the moist soil in the filter paper and allow to dry at a temperature not exceeding 60oC. Combine the soil with material obtained in Procedure No. 3.

Course: SOIL MECHANICS Group No.: 2 Name:

Experiment No.: 3 Section: Date Performed: July 4, 2015 Date Submitted: July 11. 2015 Instructor:

6. Data and Results: Sample #

Weight (g)

1 2

Purpose Particle Size Analysis

Description

Soil Constants

7. Conclusion: In this experiment we have learned that separating the soil from the pieces of rocks retained in Sieve No. 10 is by washing it in the water and the separation of the soil from the water is by filtration. This experiment is essential when we needed to conduct a soil analysis for their properties. We have concluded that rock particles contains several amount of soil that are needed for some experiment. 8. Assessment (Rubric for Laboratory Performance): CRITERIA

BEGINNER 1

I. Laboratory Skills Members do not Manipulative demonstrate needed Skills skills. Experimental Set-up Process Skills Safety Precautions II. Work Habits

ACCEPTABLE 2

PROFICIENT 3

Members occasionally Members always demonstrate needed demonstrate needed skills. skills Members are able to Members are able to set-up Members are unable to set-up the materials with the material with minimum set-up the materials. supervision. supervision. Members do not Members occasionally Members always demonstrate targeted demonstrate targeted demonstrate targeted process skills. process skills. process skills. Members follow safety Members do not follow Members follow safety precautions most of the safety precautions. precautions at all times. time.

SCORE

Time Management / Conduct of Experiment

Members do not finish Members finish ahead of time Members finish on time on time with incomplete with complete data and time with incomplete data. data. to revise data.

Members do not know their tasks and have no Cooperative and defined responsibilities. Teamwork Group conflicts have to be settled by the teacher.

Members have defined responsibilities most of the time. Group conflicts are cooperatively managed most of the time. Clean and orderly Messy workplace during workplace with Neatness and and after the occasional mess during Orderliness experiment. and after the experiment. Members require Members require Ability to do supervision by the occasional supervision independent work teacher. by the teacher. Other Comments/Observations:

Members are on tasks and have defined responsibilities at all times. Group conflicts are cooperatively managed at all times. Clean and orderly workplace at all times during and after the experiment. Members do not need to be supervised by the teacher.

Total Score (Total Score) Rating= ×100 24

9. References Murthy, V.N.S. (2011). Textbook of Soil Mechanics and Foundation Engineering. Singapore: Alken Company American Society for Testing and Materials (1999). Wet Preparation of Soil Samples for Particle-Size Analysis and Determination of Soil Constants (D-2217). Pennsylvania: ASTM International