Specific Gravity Of Soil Solids 6f554a

Abu Dhabi Campus

College of Engineering & Computer Science

Course Name: Geotechnical Engineering Laboratory Course Code: CIV 324L Laboratory Report Section 1 Specific Gravity of Soil Solids Experiment Number – 2

Date: February 21, 2013 Submitted By: March 7, 2013

Done By 1. Student Name: Waleed Nabil Ablan

ID: 1011045

Instructor’s Name: Engr. Akram A. Saif

INTRODUCTION The specific gravity of a substance, designated as Gs, is defined as the ratio of the density of that substance to the density of distilled water at a specified temperature. Since it is a ratio, the value of Gs does not depend on the system of units used and is a numerical value having no units. In soil mechanics, the specific gravity of soil solids is an important a factor in many equations involving weight-volume relationships.

that the specific gravity of soil solids refers only to the solid phase of the three phase soil system, it does not include the water and air phases present in the void space. For soil solids, Gs may be written as (ME 420L/ME 506L: Soil Mechanics Laboratory):

G s=

unit weight (¿ density )of soil solids only unit weight (¿ density )∨water

Or G s=

W s /V s Ws = ρ2 V s ρw

Where, W = mass of soil solids (g). V = volume of soil solids (cm3). Pw = density of water (glcm3). The procedure for determination of specific gravity, G" described here is applicable for soils composed of particles smaller than 4.75 mm (No.4 U.S. sieve) in size.

APPARATUS 1) 2) 3) 4) 5) 6) 7) 8) 9)

Volumetric flask (500 ml) Thermometer graduated in 0.5 C division scale Balance sensitive up to 0.01 g Distilled water Bunsen bummer and a stand (and/or vacuum pump or aspirator) Evaporating dishes Spatula Plastic squeeze bottle Drying oven

EXPERIMENTAL PROCEDURE 1. Determine and record the weight of the empty clean and dry flask, W1. 2. Place 10g of a dry soil sample (ed through the sieve No. 10) in the flask. Determine and record the weight of the flask containing the dry soil, W2. 3. Add distilled water to fill about half to three-fourth of the flask. Soak the sample for 10 minutes. Apply a partial vacuum to the contents for 10 minutes, to remove the entrapped air. 4. Fill the flask with distilled water to the mark; clean the exterior surface of the flask with a clean, dry cloth. 5. Determine the weight of the flask and contents, W3.

6. Empty the flask and clean it. Then fill it with distilled water only to the mark. Clean the exterior surface of the flask with a clean, dry cloth. 7. Determine the weight of the flask and distilled water, W 4. Where, W1 = Weight of the empty flask W2 = Weight of the flask containing the dry soil W3 = Weight of flask filled with water and soil W4 = Weight of flask filled with water

CALCULATION Sample Number W1 = Weight of the empty flask W2 = Weight of flask filled with

Trial 1 28.80 131.08

water W3 = Weight of flask filled with water

137.40

and soil Ws = Weight of the dry soil

10.21

G s=

G s=

Ws W s+(W 2−W 3 )

10.21 =2.62 10.21+(131.08−137.40)

DISCUSSION & CONCLUSION

As can be seen, the change due to the correction factor is minimal, due to the fact that? Is only one onethousandth different from 1.000? But the factor is noted, as it did change the value slightly, and the values of Gs? Are considered the more accurate value for this experiment. This brings us to the evaluation of the final answers. Since it is already known that one sample is sand, values from well-established tables can be used to compare with the calculations conducted here (Wade). Based on the accuracy of the test with sand, it can be assumed that this value is also very accurate; it is most likely accurate enough to wager a guess as to what type of soil it is. Having minimal experience in dealing with soils on a scientific level, I cannot confidently hypothesize as to which it is nor why. The color of the sample will probably make it easier to decide between the two, but as of now, my experience does not allow me to pick which type of soil it could be. Future tests on this sample will be done which will allow me to identify the soil. Fortunately, this experiment has narrowed the choices, assuming that there was as little error in this iteration of the experiment as there was with the sand (Wade).

Bibliography ME 420L/ME 506L: Soil Mechanics Laboratory. (n.d.). Retrieved March 6, 2013, from http://infohost.nmt.edu: http://infohost.nmt.edu/~Mehrdad/ME420/assets/pdf/SpecificGravity.pdf Wade, M. (n.d.). Laboratory Experiment 1 Specific Gravity of Soil Solids. Retrieved March 6, 2013, from http://student.seas.gwu.edu: http://student.seas.gwu.edu/~mattwade/SchoolStuff/SoilsLab/Lab1.pdf