Engineering Properties and Field Classification
Of Collected Soil Sample
1.0 Introduction
The objectives of the labs and the application/relevance they have in relation to construction.
1.1 Lab 1
The purpose of the Soil Collection Lab is to have the students collect a soil sample offsite from the Niagara College campus. The Moisture Content, Wet Unit Weight and Dry
Unit Weight of the soil sample will be determined in the Lab [1]. The soil sample was
taken on September 9TH, 2013, at 4536 Sixth Ave. Niagara Falls, ON, during a partly
cloudy weather condition with 20°C and 515 km/h winds. The tests performed to the soil
sample are relevant in order to determine what type of soil is underneath our future
building; cohesionless or cohesive. And then, be able to design accordingly the
proposed infrastructure or correct the soil deficiencies.
1.2 Lab 2
The students will learn and apply techniques which are suitable for field use to classify
soils. The soil collected in Lab 1 will be classified according to the Unified Soil
Classification System (USCS) [2]. The soil sample collected in Lab 1 was used in lab 2,
where it was classified according to the USCS by means of field-based techniques and
lab-based techniques to determine if the soil sample was poorly graded sand (SP),
Poorly Graded Sand with Silt (SP-SM), Silty Sand (SM), Lean Clay (CL), or Silt with
Sand (ML).
2.0 Theory
In this section, technical or theoretical background is provided to assist in the understanding of
the report.
2.1 Soil
Soil is made up of: air, solid particles, and water or other fluids [3]. Each component is
assigned weights and volumes for evaluating the sample, see Figure 2.1, on page 2.
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Figure 2.1 [4:10]
2.2 Coarse-grained or Fine-grained Soil
Soil types are classified into gravel, sand, silt, and clay, by their particle size. A coarse
grained soil particle is 0.075 mm and larger (depends on classification system used). A
coarse grained soil contains more than 50% particle sizes of 0.075 mm and greater. A
fine grained soil particle is smaller than 0.075 mm (depends on classification system
used, see Appendix C, page 21). A fine grained soil contains more than 50% particle
sizes less than 0.075 mm [4].
2.3 Size ranges for gravel, sand, fine soil particles
Particle size ranges for gravel, sand, silt, clay are different based on the soil
classification systems used. See Table 2.1 below, for an example of Unified Soil
Classification System.
Unified soil clasification system
Clasification
Inches
mm
Boulders
> 12
> 305
Cobbles
≤ 12, > 3
≤ 305, > 75
Coarse Gravel
≤ 3, > 3/4
≤ 75, > 19
Fine Gravel
≤ 3/4, > 0.19
≤ 19, > 4.76
Coarse Sand
≤ 0.19, > 0.08
≤ 4.76, > 2.0
Medium Sand
≤ 0.08, > 0.017
≤ 2.0, > 0.42
Fine Sand
≤ 0.017, > 0.003 ≤ 0.42, > 0.075
Fines (Silt & clay)
≤ 0.003, > 0
≤ 0.075, > 0
Table 2.1 [4:16]
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2.4 “Clean” gravel/sand versus a gravel/sand with fines
A “clean” gravel/sand is when less than 5% of the material is smaller than a No. 200
sieve size (0.075 mm). A gravel/sand with fines is when more than 12% of the material
is smaller than a No. 200 sieve size (0.075 mm) [3:176].
2.5 Well graded versus a poorly graded gravel/sand
A well graded gravel/sand has a wide range of particle size and substantial amounts of
intermediate particle size. A poorly graded gravel/sand has mostly one size particle or a
range of sizes with missing intermediate particle sizes [3:176].
2.6 Field based classifications
Field based classifications start with visual observations of soil sample. The amount of
particles visible to the eye determines classification. Organic soils are determined by
colour and smell. A dilatancy, dry strength, and toughness test is performed on fine
grade soils to complete classification group (see Appendix B, page 14).
3.0 Procedure
This section will make reference to directions outlined in the resource material, and/or test
standards.
3.1 Lab 1
See Appendix A, page 8
3.2 Lab 2
See Appendix B, page 14
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4.0 Observations
This section will detail the observations and results of the labs.
4.1 Lab 1
Observations of the soil collected are listed below (see Table 4.1).
Lab 1 – Soil Collection Observations
Location
4536 Sixth Ave., Niagara Falls, ON (see Figure 4.1a + b )
Date
Sept. 9, 2013 7:00 PM
Weather
Partly cloudy, 200°C, Wind 15 km/h, 74% Humidity
Ground conditions
Damp
Depth from which soil sample was taken
0.46 m ( see Figure 4.2a, page 5)
Depth of hole
16 cm
Width of hole
24 cm ( see Figure 4.2b, page 5)
Length of hole
22 cm ( see Figure 4.2c, page 5)
Volume of hole
8448 cm³
Mass of soil sample + garbage bag
16.20 kg
Mass of garbage bag
138.8 g
Mass of moisture can
23.35 g
Mass of moisture can with wet soil sample
176.83 g
Mass of moisture can with oven dried sample 148.59 g
Mass of moisture evaporated from sample
28.24 g
Mass of oven-dried soil sample
125.24 g
Table 4.1
Figure 4.1a
Figure 4.1b
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FIGURE 4.2a
FIGURE 4.2b
FIGURE 4.2c
The calculated soil mass index relations are listed below (see Table 4.2).
Soil Mass Index Relations
Properties
Metric
Imperial
Moisture Content, ω %
22.55%
22.55%
Wet Unit Weight, γT
1911.90 kg/m³ 119.36 lb/ft³
Dry Unit Weight, γD
1560.10 kg/m³ 97.39 lb/ft³
Table 4.2
For calculation details see Appendix A, page 13.
4.2 Lab 2
The following are the observation results of field classification of soils in accordance
with the Unified Soil Classification System (USCS):

98% of the soil (by weight) was not visible to the naked eye, indicating that the
sample was a fine grained soil.

The soil was found to be inorganic; it did not have a smell and the colour was a
dull brown.

The following tests were performed with the following results:
o Dilitancy Test - showed no reaction, no water appeared when a small amount of
the sample was flattened and shaken around in hand.
o Dry Strength Test - very high and did not break between thumb and hard
surface.
o Toughness Test - it had some stiffness and started cracking at 6 mm.
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5.0 Discussion of Results
In this section, observations and results from the labs will be discussed.
5.1 Field Classification of Soils
98% of the soil not being distinguishable to the naked eye resulted in it being a fine
grained soil according to the Field Classification of Soils chart (see appendix B). The
lack of colour and the fact it did not smell contributes to it being inorganic matter as
organic matter has an earthy smell, this resulted in it being a silt or inorganic clay (see
appendix B). Three tests were performed to determine which type of soil it is. The
Diltancy test identifies the character of the fines in a soil through how quickly the water
appears and disappears if at all; the test showed no reaction resulting in it being clay
[3:182]. The Dry Strength test measures the character and quantity of the colloidal
fraction contained in the soil [3:182]. Its crushing characteristics were very high and did
not break between the thumb and hard surface, which is a characteristic of clays in the
CH group. The Toughness test shows the consistency of soil near its plastic limit
[3:183]. The results were that of a medium stiffness as it started cracking at 6mm which
led to the indication that the soil had the characteristics of CH – Inorganic Clay (C) with
High plasticity (H).
6.0 Conclusions
This section contains statements that will give clear answers to the objectives in the
Introduction.
6.1 Lab 1
It was determined, after the calculations were made from the soil sample, that it had the
following engineering properties:
Moisture Content – ω% = 22.55%
Wet Unit Weight – γT =
1911.90 kg/m³
119.36 lb/ft³
Dry Unit Weight – γD =
1560.10 kg/m³
97.39 lb/ft³ Table
6.2 Lab 2
It was determined through field testing, using the soil sample acquired in Lab 1, that the
sample was clay according to the Unified Soil Classification System (USCS) [2]. Further
testing using the Diltancy test, the Dry Strength test, and the Toughness test
determined that the sample was cohesive and was concluded that the soil was CH –
Inorganic Clay (C) with High plasticity (H).
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References
[1] Materials II, CIVL 1356, “Lab 1 – Soil Collection Lab.” [On-Line]. Available:
https://niagara.blackboard.com/bbcswebdav/pid-1532729-dt-content-rid-3837949_1/xid3837949_1 [Sep., 2013].
[2] Materials II, CIVL 1356, “Lab 2 - Field Classification of Soils.” [On-line]. Available:
https://niagara.blackboard.com/webapps/blackboard/execute/content/file?cmd=view&content_i
d=_1532734_1&course_id=_107607_1 [Sep., 2013].
[3] P. F. Boles et al. Pearson Construction Technology – CIVL 1256/1356, Materials I,
Materials II (Soils). Boston, MA: Pearson Learning Solutions, 2011, pp.153-189.
[4] Materials II,CIVL 1356 “Week 2 PowerPoint Notes.” [On-line]. Available:
https://niagara.blackboard.com/bbcswebdav/pid-1532732-dt-content-rid-3859450_1/xid3859450_1 [Sep., 2013].
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