The Soil Materials Pore Spaces to Assess the Significant Porosity - Research Proposal Example

Determining Soil Bulk Density, Particle Density, And Total Porosity

Purpose

The purpose is to study the soil materials pore spaces to assess the significant porosity. To determine how soil bulk density, particle density, and total porosity change depending on particle, size, and shape.

Physical Lab Reports Procedures

Sample Collection

• Choose three sampling sites with different soils, i.e., sand, silt, and clay soils
• Ensure that the selected surfaces are moist.
• Use a spade to clear the surfaces and then push the steel ring into the soil gently.
• Collect soil around the ring and place it in a plastic bag.
• Follow similar procedures in all sites with the soils mentioned above.

Calculation of Bulky Density

Bulk Density (g/cm3) = Dry soil weight (g)/ soil volume (cm3)

Soil volume= ring volume

• Calculate the volume of the ring using the formula 3.14 x r2 x ring height.
• To calculate the dry weight of the soil, weight the empty cylinder in grams (W1)
• Remove the sampled soils from the bags into the cylinders and warm for ten minutes in the microwave.
• Weight the dried soil plus the cylinder (W2)
• Dry soil weight =W2 – W1
• Therefore, Bulky Density = (W2 – W1) grams/ soil volume (cm 3)
• Report the procedure for all three soils (sand, silt, and clay).
• Record results in a table

Calculation of Particle Density

Particle density = oven-dry soil weight/volume of soil solids

• Measure the mass and volume of the solid particles in the sampled soils.
• Put the sampled soils in a flask and add distilled water.
• Boil to remove all the air from the sampled soil.
• After cooling the boiled soil, add a specific volume of water.
• Measure the mass of the mixture (soil + water)
• The mass of the dry soil is calculated by subtracting the mass of the added water from the mass of soil plus water.
• The particle density is calculated from the mass of solid particles in a specified volume.
• Repeat the procedure in all samples.
• Record results in a table

Results

The effect of average particle size on total porosity of sand, silt, and clay is as follows: Porosity is that portion of the soil volume occupied by pore spaces. In the experiment, the total porosity percentage of sand is 37%; that of silt is 51%, while the clay is 65%. Therefore, the total porosity, depending on the average particle size, increases with the increase in pore spaces within the grain. For instance, porosity in the sand is higher, average in silt, and significantly reduces in clay. This is because sand contains many pores and hence has less water than silt and clay.

The effect of overall size uniformity on total porosity (nonuniform sand (concrete) vs. uniform sands) stands as follows; Total porosity tends to increase with the decrease in soil particles. Lowest porosity, therefore, exists in the sand since it contains the largest particles as compared to the rest of soils such as clay. Soils with the smallest particle, such as clay, on the other hand, tend to highest porosity. Lowest total porosities can, therefore, be observed in nonuniform sands as opposed to uniform sands.

The effect of particle shape on total porosity (round vs. angular sand) also depends on various variables. Soil porosity is dependent on the size, shape as well as the mixture of grains. Particle shape, for instance, influences some constructing properties such as permeability, internal friction angle, among others. Particles with round shapes can be compacted a lot more closely; hence, the porosity between such particles is low (Jaromír et al. 2018, 338). Round particles have fewer pore spaces between them, and the areas influence their ability to compact together hence lower total porosity and higher bulk densities. However, particles with the angular shape tend to contain higher total porosity and lower bulk densities as compared to round sands since the angular sands usually fall together irregularly. In the process, they, therefore, create larger pore spaces.

Some of the soils tested have organic matter present, and this is for some reason. Based on my review of the information and calculations done on the missing information, the conclusion is that the average porosity is lower in concrete sand compared to the other samples. The main reason for this conclusion is that concrete sand comprises particles with different sizes, which are likely to have fewer voids in the profile is calculated. The USGA sand contained better results as the very angular sand, which is expected to be in the middle range as opposed to round sand since it (USGA sand) has voids due to its angles.

Clay topped in the calculations with 65% porosity due to its more beautiful grains and a higher volume of open spaces. Permeability in clay is also usually low hence the ability to hold lots of water as compared to other particles such as sand in which water passes with ease. The best method of confirming the availability of any organic matter within the samples was to observe the weight lost after the samples were oven-dried. The technique is also known as 'lose on ignition' as the organic matter is burnt out. The information provided inhibits calculating the presence of the organic matter since the weight of soil before it was dried is not provided. The information provided is after the soil was baked.

The presence of organic matter in the sampled soils affects their particles density. Among the three samples, silt has a lot of organic matter, clay has an average organic matter, while sand has the lowest amount of organic matter. Soils with large amounts of organic matter have lower weight as compared to those with mineral matter, and this explains why silt has a lower weight compared to clay and sand.

Bulk Density

USGA sand

Very Round Sand

Concrete sand

Very Angular USGA sand

Silt loam Topsoil

Clay

List the 3 Samples in each box

1,2,3

1,2,3

1,2,3

1,2,3

1,2,3

1,2,3

Weight

151, 164, 166

160, 159, 166

173, 174, 167

148, 158, 155

155, 121, 128

77, 74, 64

Volume

96, 97, 95

96, 96, 96

96, 103, 96

97, 102, 97

98, 105, 101

100, 96, 102

Bulk Density

1.57, 1.69, 1.61

1.66, 1.65, 1.73

1.80, 1.69, 1.74

1.52, 1.55, 1.59

1.17, 1.55, 1.26

.77, .77, .62

Ave. Bulk Density

1.62

1.68

1.74

1.55

1.19

0.72

Particle Density

USGA Sand

Very Round Sand

Concrete Sand

Very Angular USGA sand

Silt Loam Topsoil

Clay

List the 3 Samples

in each box

1,2,3

1,2,3

1,2,3

1,2,3

1,2,3

1,2,3

Weight

51.7, 51.4, 49.7

50.7, 50.2, 49.2

48.5, 51.8, 48

48.5, 51.2, 48.1

49.2, 50.4, 52

50.2, 50.9, 50.9

Volume increase due to soil

19.9, 19.2, 18.6

19, 19.4, 19

19.6, 18.6, 18.9

19.2, 19.3, 18.9

20.7, 20.7, 21.10

25, 24,25

Particle Density

2.59, 2.67, 2.67

2.67, 2.58, 2.59

2.48, 2.78, 2.54

2.52, 2.65, 2.54

2.37, 2.43, 2.46

2.00, 2.12, 2.03

Average Particle Density

2.64

2.61

2.6

2.57

2.42

2.05

Average Total Porosity

Average Total Porosity

(Michael McAfee)

Average Total using Group Results

Difference %

USGA Sand

39%

39%

0.00%

Very Round Sound

36%

35.60%

0.40%

Concrete Sand

33%

33%

0.00%

Very Angular USGA sand

40%

39.20%

0.80%

Silt Loam Topsoil

51%

50.20%

0.80%

Clay

65%

65%

0.00%

Work Cited

Říha, Jaromír, et al. "Assessment of empirical formula for determining the hydraulic conductivity of glass beads." Journal of Hydrology and Hydromechanics 66.3 (2018): 337-347.