What is soil density index?
DEFINITIONS. Relative density or density index is the ratio of the difference between the void ratios of a cohesionless soil in its loosest state and existing natural state to the difference between its void ratio in the loosest and densest states.
What is dry density test?
Dry density is calculated by dividing the weight of the wet soil by its water content in percent. The percent compaction for the field density test is calculated by dividing the dry density of the soil by the maximum dry density from the proctor test.
What is maximum dry density?
• Optimum Moisture Content (OMC) is the water content at which the soil attains maximum dry density. • Maximum Dry Density (MDD) is the dry density of soil corresponding to Optimum Moisture Content.
What is the use of SPT N value?
The SPT (N) value provides information regarding the soil strength. SPT (N) value in sandy soils indicates the friction angle in sandy soils and in clay soils indicates the stiffness of the clay stratum.
What is bulk unit weight of soil?
Bulk Unit Weight (γ) This is typically 15 kN/m3 for many top soils but can vary between 11 kN/m3 for a loose dry soil to 18 kN/m3 for dense wet soils.
What is the formula for density index?
Explanation: The density index is defined as the difference between the voids ratio of the soil in its loosest state emax and its natural void ratio e to the difference between the voids ratio in the loosest and densest state. ID=\frac{(e_{max} – e)}{(e_{max}-e_{min})}.
What does it mean to have 95% compaction?
95 percent compaction means that the soil has been compacted to 95 percent of the possible density of the soil through compactive efforts. Maximum dry density, along with optimum moisture content, is determined in the laboratory and provides the target for field compaction.
How do you calculate wet density?
Remember that the mass of the wet soil needs to be expressed per the unit volume of the mold used. The mass of the wet soil in kilograms is multiplied by 66.22 to determine the wet density in lb/ft3.
How is OMC calculated?
6. To calculate the amount of liquid required per m3 to achieve OMC, multiply the answer in #5 (4grm) by 9000. Or, simply by a factor of 9. (4grm x 9 = 36ltr of liquid) This will give you the total amount liquid liters (36ltr) to achieve OMC.
What is the SPT for dense sand?
The standard penetration test (SPT) is an in-situ dynamic penetration test designed to provide information on the geotechnical engineering properties of soil….Correlation with soil mechanical properties.
| Relative density | SPT N value | Bulk density (kg/m3) |
|---|---|---|
| Medium | 11 – 30 | 1 750 – 2 100 |
| Dense | 31 – 50 | 1 750 – 2 245 |
What does SPT N60 mean?
N60 is what a safety hammer (cathead and rope) N value is estimated to be uncorrected. An auto hammer is estimated to be about 80% efficient. 1.333 times more than a safety hammer.
What is unit of weight density?
Density is commonly expressed in units of grams per cubic centimetre. For example, the density of water is 1 gram per cubic centimetre, and Earth’s density is 5.51 grams per cubic centimetre. Density can also be expressed as kilograms per cubic metre (in metre-kilogram-second or SI units).
What is the range of density index?
e = emax and hence ID = 0. When the natural deposit is in its densest state, e = emin and hence ID = 1. For any intermediate state, the density index varies between zero and one.
What is meant by 98% Proctor?
95% compaction is just 95% of the Proctor density, whereas 98% compaction is 98% of the Proctor density. If the Proctor density is 100 (let’s ignore units here), and the percent compaction is 95, that means that the soil that was just packed has a density of 95. 95/100 = 95% = 95% compaction!
How do you get 98 compaction?
98% compaction is simply the result of the comparison between field values and lab values for a specific soil. 98% compaction just means that the density of the material placed on site is 98% of the maximum density determined in the lab.
What is wet density?
A quantity of soil or soil and aggregate mixture is prepared at a determinable moisture content and compacted in a standard mold using a manual or mechanical rammer. The wet mass of this compacted sample is divided by the volume of the mold to determine the wet density.
What is the density of sand in lb/ft3?
Density of Sand, dry lb ft3 = 100.0095928812 lb/ft³. See density of Sand, dry in hundreds of units of density measurement grouped by weight.
What units are used to measure the density of sand?
See density of Sand, dry in hundreds of units of density measurement grouped by weight. grain per… gram per… kilogram per… long ton per… microgram per…
What is the density of sand when it is wet?
When the sand is wet, water is in the sand, also affecting the total matter in the volume. The mean density of the different conditions of sand are as follows: Loose Sand: 1442 kg/m 3. This is dry sand that has been moved or otherwise agitated to loosen the natural packing process.
What is specific density measured in SI units?
SI Unit of Density Each substance has a specific density. Generally, the density of water (which is approximately about 1 gram/cubic centimeter) is taken as the standard value for calculating the density of substances. However, the SI unit of Density is measured using kilograms per cubic meter (kg/m3).