How do you measure soil compaction on field?

Asked By: Brenton Ayadi | Last Updated: 18th April, 2020
Category: business and finance environmental services industry
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Determination of adequate compaction is done by determining the in-situ density of the soil and comparing it to the maximum density determined by a laboratory test. The most commonly used laboratory test is called the Proctor compaction test and there are two different methods in obtaining the maximum density.

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Just so, how do you measure soil compaction?

Soil compaction occurs below the surface, so it's hard to spot. The best way to test is to probe the soil with a compaction tester to a depth of 36" to 48". The testing rod should move down through the soil with steady, even pressure, Hard, compacted soils resist penetration with the rod.

Also, what does it mean to have 95% compaction? 95% compaction means that in-situ soil will be compacted to 95% of the maximum dry density by means of roller of different kinds (depending on the soil characteristics). Usually we do proctor compaction test to find out the maximum dry density(MDD) and optimum moisture content (OMC) of a soil.

Besides, how is a compaction test done?

Press the soil into the Proctor soil compaction mold in three to five layers (lifts) using the straight edge and soil compaction hammer/drop weight. Then weigh the sample. Oven dry the mold and weigh the sample again.

How do you calculate compaction?

Divide the volume of the loose trash by the volume of the compacted trash to achieve the compaction ratio. As an example, 16 cubic feet of loose trash compacted into a 4 cubic feet volume would have a ratio of four, or four to one.

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How do you fix soil compaction?

Make compost or buy it at a lawn and garden store. The organics are broken down by organisms such as earthworms that aerate the soil. For badly compacted soil, add a 50% compost blend to regular soil and 25% in sandier soils. Avoid amending soil with inorganic material such as sand if possible.

How is soil depth measured?

The depth of a soil is measured by how far below the surface plant roots can extend before being stopped by barriers, such as rock, sand, gravel, heavy clay, compacted dirt, or cement. Below the topsoil (usually only a few inches deep) lies another layer called subsoil.

How can we prevent soil compaction?

To prevent soil compaction, avoid wheel traffic and tillage of wet soils; use wider tires, dual tires, or tracks; minimize tractor weight; maintain the minimum tire inflation pressure needed for an acceptable tire life; avoid using oversized equipment; try to combine field operations to make fewer passes over the field

What is SPT value?

The Standard Penetration test (SPT) is a common in situ testing method used to determine the geotechnical engineering properties of subsurface soils. of penetration is reported as SPT blowcount value, commonly termed "standard penetration resistance" or the "N-value".

How do I get 95 compaction?


For example, specifications often require compaction to be 95 percent of Standard Proctor. This means the on-site soil density must be equal to 95% of the maximum achievable compaction. Compaction is achieved by applying three basic types of force to the soil mass. the soil particles.

How do you measure soil strength?

Perhaps the most widely used device to measure soil strength in the field is the cone penetrometer.

What is MDD of soil?

Optimum moisture content/maximum dry density (OMC/MDD) – when placing soils as fill materials, it is important to achieve suitable compaction, primarily in order to reduce the susceptibility of a soil to settlement.

Why is soil compaction needed?

Compaction is the application of mechanical energy to a soil to rearrange the particles and reduce the void ratio. The principal reason for compacting soil is to reduce subsequent settlement under working loads. This is important if the soil is being used to retain water such as would be required for an earth dam.

What is FDT test?

FDT which is acronym of Field Density Test is a Quality Control test carried out at site for knowing the increased density or compaction achieved at site on the soil layer.

What is MDD test?


The determination of maximum dry density and optimum moisture content of soil is a measure of compaction level of soils. This can be measured by mainly two methods standard Proctor Compaction Test and Modified Proctor Compaction Test.

Is light a compaction test?

? proctor test is also known as light compaction test as per BIS. ? AASHO developed a modified test to give a higher standard of compaction and is known as modified proctor test. The same is also known as heavy compaction test as per BIS.

How is CBR value calculated?

C.B.R. = (PT/PS) X 100
The C.B.R. values are usually calculated for penetration of 2.5 mm and 5 mm. Generally the C.B.R. value at 2.5 mm will be greater than at 5 mm and in such a case/the former shall be taken as C.B.R. for design purpose.

What is the zero air voids line?

Zero Air Voids. It means the soil is fully saturated, with the air is not present in the pores of the soil mass. It is obtained from the compaction test. The graph is plotted for dry density versus water content. To draw the zero-air void line, the dry density is to be calculated and that is expressed as below.

How much is a soils report?

The actual fee will very depending on project and site conditions. Typical soil report fees vary from about $2,700 to $4,000 for new projects, and about $3,800 to $6,000 or greater for forensic or relatively complicated existing projects. Soil reports are almost always bid on a lump-sum basis.

What is the purpose of compaction test?


The aim of the test is to establish the maximum dry density that may be attained for a given soil with a standard amount of compactive effort. When a series of samples of a soil are compacted at different water content the plot usually shows a distinct peak.

What are the different methods of compaction?

The method of compaction is primarily of four types such as kneading, static, dynamic or impact and vibratory compaction. Different type of action is effective in different type of soils such as for cohesive soils; sheepsfoot rollers or pneumatic rollers provide the kneading action.

How is compaction measured?

Compaction is achieved by applying a pre s s u re on the surface or by vibrating the soil mass. To find out how well a soil has been compacted we must measure the dry unit weight or dry density in pounds per cubic foot. Dry density is a measure of the weight of solid material present in a cubic foot of soil.