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lab report on sieve analysis of soil...

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UNIVERSITI MALAYSIA SARAWAK FACULTY OF ENGINEERING CIVIL ENGINEERING DEPARTMENT

KNS 2591 CIVIL ENGINEERING LABORATORY 3

Code & Title

KNS 2591 / CIVIL ENGINEERING LABORATORY 3

Lecturer Group Name and matric no.

1K 1. AHMAD HAZWAN BIN ROSLI (64591) 2. JOANNA NELSON OKIONG (64800) 3. MUHAMMAD LUQMAN HAKIM BIN AMER SAIFUDE (64955) 4. NURHAFIZZAH BINTI MOHD ALDAH (67293)

FACULTY OF ENGINEERING KNS 2591 Civil Engineering Laboratory 3 Laboratory Report

TABLE OF CONTENT CONTENT

PAGE

1.Title

3

2.Introduction

3

3.Objective

4

4.Apparatus and Materials

4

5.Procedure

4-5

6.Results and Calculation

6-8

7.Discussion

9-10

8.Conclusion

11

9.Reference

11

10.Appendix

Page 2

FACULTY OF ENGINEERING KNS 2591 Civil Engineering Laboratory 3 Laboratory Report

Title L1- Sieve Analysis Introduction Soils are complex mixtures of minerals, water, air, organic matter, and countless organisms that are the decaying remains of once-living things. In the other words, soil is considered as fine earth which covers land surfaces as a result of the in-situ weathering of rock materials or the accumulation of mineral matter transported by water, wind, or ice (Northcliff, 2012). Soils consist of grains such as mineral grains and rock fragments with water and air in the voids between grains. The water and air contents are changed by changes due to the conditions and location. Soils can be unsaturated or perfectly dry (have no water content), or be fully saturated (have no air content), or be partially saturated (with both air and water present). Although the size and shape of the granular content rarely changes at a given point, they can vary considerably from point to point (Davison, 2000). In the engineering field, it is important to understand the significance of particle size, shape and composition, and of a soil's internal structure or fabric to design a strong foundation of a structure. There are several engineering soil classification systems such as Unified Soil Classification System (USCS) and AASHTO Soil Classification System. According to USCS, there are some tests that are being tested to identify the physical characteristics of soil. According to USCS, sieve analysis test and Atterberg’s limits test are used to classify the soil. This test method is performed in according to ASTM D422.Sieve analysis is a method of a sample of soil that operates by dividing that sample into fractions. Each of them consists particles of the same size between some definite limits, these being the openings of standard test sieves. Before sieving, the soils were air dried to avoid lumps of fine particles and also to prevent clogging of the finer sieves. Grading curves with the ordinates representing cumulative percentage passing and the abscissa the sieve opening to logarithmic scale can be drawn to study the results of sieve analysis of soil. By using these curves, it is possible to see whether the grading of a given sample conforms to that specified or is too course or too fine, or deficient in a particular size.

Page 3

FACULTY OF ENGINEERING KNS 2591 Civil Engineering Laboratory 3 Laboratory Report

Objectives 1. To determine the percentage of different grain sizes contained within a soil sample according to ASTM D422: Standard Test Method for Particle-Size Analysis of Soils 2. To generate a semi-logarithmic plot that displays the particle size distribution of the soil

3. To identify the grading of the soil using the data points on the graph.

Apparatus 1. Sieve shakers 2. Dry oven 3. Soils 4. Sieve shacks

Procedure

1. A soil sample was prepared and was put in oven dry for at least 24 hours. The soil was weight before entering the oven dry and the mass was recorded. 2. A set of clean sieve shacks ranging from size 14.000mm, 10.000mm, 6.300mm, 5.000mm, 2.360mm, 2.000mm, 1.180mm, 0.600mm, 0.425mm, 0.300mm, 0.212mm, 0.150mm, 0.063mm and bottom pan (passing 0.063mm) was prepared in ascending orders. 3. The empty clean sieve shack was weight and the mass was recorded before conducting the experiment. 4. The sieve shack was stacked in ascending order starting from 14.000mm on the top until 0.063mm and finally a pan was put on the bottom part of the shacks. 5. The soil sample was poured carefully on the top of the stacked sieve and the top was covered with a sieve cap.

Page 4

FACULTY OF ENGINEERING KNS 2591 Civil Engineering Laboratory 3 Laboratory Report

6. The stack of sieve shack was then put on the mechanical shaker and starts the machine leave the soil sample for at least 10 minutes. 7. After 10 minutes, the stack was allowed to rest and the lightweight particle soil was allowed to settle before continuing the experiment. 8. The sieve was carefully removed from the stack and the mass was recorded according to the corresponding masses. 9. The obtain mass of each sieve plus soil was subtracted with the mass of empty sieve in order to obtain the mass of soil passing. 10. The percentage error of the initial mass of the soil sample was computed to the sum of the soil sample retained. 11. The percentage passing or percentage finer was calculated starting from 100 percent and was subtracted with the percentage retained on each sieve as a cumulative procedure. 12. A semi logarithmic plot of grain size versus percentage of finer was plotted. 13.

Page 5

and

was computed for the soil.

FACULTY OF ENGINEERING KNS 2591 Civil Engineering Laboratory 3 Laboratory Report

Data and result

Diameter

Mass of empty Mass

(mm)

sieve (g) 471 477 520 519 548 397 487 392 367 368 374 350 330 373

14.000 10.000 6.300 5.000 2.360 2.000 1.180 0.600 0.425 0.300 0.212 0.150 0.063 Pan (passing

of Soil

Percentage

Percentage

sieve + soil retained (g)

retained (%)

passing (%)

retained (g) 471 477 555 558 688 414 584 463 405 385 393 360 340 378

0.0 0.0 7.0 7.8 28.0 3.4 19.4 14.2 7.6 3.4 3.8 2.0 2.0 1.0

100.0 100.0 93.0 85.2 57.2 53.8 34.4 20.2 12.6 9.2 5.4 3.4 1.4 0.4

0 0 35 39 140 17 97 71 38 17 19 10 10 5

0.063) Total weight

Calculation Percentage error = % error = Page 6

= 0.4%

498

FACULTY OF ENGINEERING KNS 2591 Civil Engineering Laboratory 3 Laboratory Report

Since the error for trial above is below the accepted value of 2.0%, the trials were both accepted.

The cumulative percent retained in each sieve are also computed as follows:

While perfect finer is computed as:

=100%

-

96.6%

= 3.4% Particle size distribution graph is then obtained by plotting the sieve opening size on the xaxis versus the percent passing on the y-axis as presented below:

Particle Size Distribution 100 90

Percentage Passing (%)

80 70 60 50 40 30 20 10 0 100

10 D60 D30

1 Soil Sample Sieve Opening Size (mm) D30

0.1 Linear (Soil Sample) D10

0.01 D60 D10

Graph 1: Particle Size Distribution of Soil

In order to classify the grading of the soil sample, the coefficient of uniformity and curvature were calculated as follows: Page 7

FACULTY OF ENGINEERING KNS 2591 Civil Engineering Laboratory 3 Laboratory Report

Where in and

is the coefficient of uniformity,

,

,

are particle diameters at 60% , 30% , and 10% passing. Using equation above, we

computed the coefficients as:

Discussion

Page 8

is the coefficient of curvature, and

FACULTY OF ENGINEERING KNS 2591 Civil Engineering Laboratory 3 Laboratory Report Sieve analysis is one of the common methods used to find soil particle size distribution, where the soil sample is shaken through a set of sieves with progressively smaller opening. It is expressed as a percentage of the total dry weight. Based on the experiment that we have done, we used a total of 13 sieves in a set with the opening of 14mm, 10mm, 6.3mm, 5mm, 2.36mm, 2mm, 1.18mm, 600μm, 425μm, 300μm, 212μm, 150μm and 63μm respectively. The generated particle size distribution graph which can be obtained from performing sieve analysis can be used in various ways including finding out the soil grading as well as percentage content of coarse and fine material in the soil sample. We manage to determine whether the soil is uniformly graded or not by calculating the coefficient of uniformity and curvature as shown in the calculation section above and comparing the coefficient with the Unified Soil Grading Criteria as shown in the Table A below : -

Criterion

Material Gravel Uniformity Cu >4 Curvature 1< Cc 6 1< Cc...