Rearrangement of soil particles

Rearrangement of soil particles

Rearrangement of soil particles
Introduction:
Know your Rearrangement of soil particles since ancient times when mankind began to build a dam where the old Rearrangement of soil particles is the process of passing the soil of large numbers of workers and the animals soil broken multiple times. And the railway bridges in the beginning to leave the compaction of soil compaction for several years under the influence of the weight before placing the gravel layer above. And the methods used in ancient blood and soil mass approximate to that Proctor made his research in 1933 enter the scientific method in this area.
Definition compaction
Compaction is the rearrangement of soil particles to expel all the air spaces of the soil and is done by using mechanical means and the resulting decrease in the size of air spaces and an increase in the density of the soil. And compaction of different stiffness that the latter is the gradual expulsion of water from saturated soil using the constant stress and a concomitant decrease in size.
The importance of compaction application engineering
Earthen dams in the area of the blood soil reclamation in the dam increase immunity to the penetration of water, which reduces the amount of water leaked from it. The shear strength of the bridge Mdmuk a good help to the stability of the landfill and its resistance to sliding.
And in the field of roads and airports, these engineering capacity exceeding gestational If you created on the basis of Mdmuk well.
And in improving the properties of the soil in the replacement
Compaction of the most important processes required to stabilize the soil, whether an article was added or not added the installation.
Test compaction process
Test compaction process aims to create a situation in the Standard as a basis and guided to make the process of compaction at the site.
And there are many practical experiences that depend on the method and type of compaction, and compaction is divided into the following types:
- Dynamic compaction: where is the compaction by a hammer may fall from a certain height. - Compaction Bajn: where is the penetration and compaction by a multitude of soil and then some kneading occurs in the soil during compaction. - To carry static compaction: the compaction of soil under load in the form of static. - Compaction Shake: where is the blood of making the soil vibration.
Standard Proctor test
Dried soil sample after crushing so that the drying antenna in the range of 5 as the size passing sieve 20 mm, then add the amount of water according to the kind of experience so give the moisture content between 4% to 6% for the sandy soil and Zlatip and value ranging from 8% to 10% of the soil clay and alluvial then placed a sample on the three layers in the template component in a hollow cylinder diameter 10.2 cm and height of the internal 1.6 cm (giving a size of about 944 cm 3) and that this CD has over the top height of 6 cm and compaction of each layer of three layers by tapping 20 the accuracy of a hammer weighing about 2.5 kg and 5.1 cm in diameter and fall height of 30.5 cm and then removed the upper extension of the cylinder and settled the soil inside the cylindrical mold and then weighed to the content of the soil to calculate the density of the wet sample and its water content.
Proctor test average
Last American Federation of Government staff road improvement in the standard Proctor test included placing the sample on the 5 layers and weighing 4.5 kg hammer falling from the height of 45 cm and this shows that the more compaction effort, the largest dry density for the same soil is greater than the maximum and containing less moisture.
Theory of compaction
The results of the tests that compaction dry density increases when the blood with increasing soil moisture content under any effort blood
To inform the sample moisture maximum dry density and then decline after the increase in humidity at the maximum. There are many theories to explain this, including that if the moisture in the soil is low, the particle Tnglv a thin layer of water and air that separates these particles acquire an air pressure where the air is initially offline atmosphere. If Dmokt granules with each other to refrain air connection is located in the spaces, the air pressure of air trapped in the spaces more than the atmospheric pressure by depends on the degree of convergence of the granules from each other, and the volume of air trapped in pockets of the convergence of the resulting particles. And whenever a large volume of air trapped when the pressure was small and vice versa.
The case of extreme humidity resulting in a decrease in the proportion of trapped air and the remainder of the compaction effort until it fails to overcome the frictional resistance between the small particles resulting in an increase in the proportion of pores and thus a decrease in dry density and this process will continue with increasing moisture to the to reach moisture, it is then the proportion of air voids less as possible.
And if the humidity increased this limit, the trapped air is greater than the compaction effort, which fails to compress the air trapped or overcome the friction between the particles. And this result is a decrease in the density of dry soil and an increase in the proportion of pores and air voids.
And the foregoing it can be concluded that the pressure in the spaces Almtwald air during compaction is scientific, which plays a major role in the formation of compaction curve. - Factors affecting the compaction:
1 - water content: dry density than in increasing the water content until it reaches its content of soil water to the maximum value and then decreasing dry density increase of water content.
2 - the amount of compaction: Each soil has a certain type of proper compaction, and increase energy compaction increase the value of the maximum dry density and reduces the optimum water content and the general effort to increase the compaction or compaction energy to make the curve is moving north to the top.
3 - soil type: the maximum dry density depends on the type of soil. And coarse grained soils with a gradient to have a maximum dry density greater than those soils with a filler. And clay, have a less high density.
4 - Method of compaction: impact on the values of compaction and include the method of compaction whether parametric or ring on the weight of hammers and how to compaction (dynamic or static, kneading or mashed) and the time of compaction and exposed area of the blood.
5 - Add-ons: There are some additions that can be used to improve the qualities of compaction.
The impact of compaction on soil properties
- Increases the compaction of the soil shear strength. 2 - more than the carrying capacity of the soil. 3 - reduces the ability of the soil compression and landing. 4 - compaction reduces the permeability of the soil and thus decrease their ability to leak water.
Methods of compaction at the site
Blood performs soil at the site in the following ways: A - compaction Baherasat: There are machines mashing several types: - Mashers soft calf: and are known Behrasat three-wheel and there are different weights. - Mashers with windows blown under pressure: it is composed mashers him several small wheels with tires inflated and heavy weighs about 200 tons of them and stop the passage of this number Herasat and pressure caused by soil compaction on the degree and the required thickness of the soil.
- The Mashers sheep: it is composed of hollow steel cylinders with prismatic feet distributed on the surface of CDs and can be changed by the weight of cylinders filled with water.
B - compaction hammers: The compaction by tapping rods, hammer and weight ranges from 30 to 150 Kg, of which weigh up to one ton.
C - Shake compaction: is your blood soil using updated equipment for vibration. And some of which is a manual for small business and some are huge. And from these so-called float vibration, which contains a cylinder vibrating length 2 m and the external diameter of 43 cm and down the cylinder vibratory meet the soil by pushing water from the bottom and then displays the cylinder vibration Vtadmk soil around it and when it is rolling added soil again on the cylinder then remove the cylinder by 30 cm and then repeat the process again. And uses this type of blood depths of up to nine meters.