Nylon fibre was used to reinforce the expansive soil specimens. Correlation between swelling index of bentonite clay and the. Standard test method for expansion index of soils1. In many cases, the shrinking and swelling of expansive clays in response to mois. Im just not sure how you convert free swell into a design value for the foundation. Differential free swell index is the increase in volume of soil, without any external constraints, only on submergence in water. Engineering correlations for the characterisation of. Definition free swell index is the increase in volume of a soil, without any external constraints, on submergence in water. Pdf on feb 19, 2019, rakesh kumar dutta and others published prediction of free swell index for the expansive soil using artificial neural. Prediction of swelling characteristics of remoulded and. In this method, which is a standard method of practice specified by the bureau of indian standards is. Both caking and free burning coals can be burned without difficulty in pulverized coalfired boilers. Classification procedures for expansive soils citeseerx.
Free swell index test of soil, fsi test of soil asper is. Remoulded compacted soil, when soaked in water, absorbs water and swells. The amount of certain clay minerals that are present, such as montmorillonite and smectite, directly affects the shrinkswell capacity of soil. Subbituminous coals and lignite are classified as freeburning coals. Key aspects that need identification when dealing with expansive soils include. Expansive soil of a high free swell index fsi was used in the experimental study. Engineering properties of bentonite stabilized with lime. Swell test apparatus is designed to determine the swelling pressure developed by soil specimens moulded to desired densities at known moisture content. Another additive that as been found to be quite promising in reducingh the swelling characteristics and improving the engineering behavior of expansive soils is fly ash.
Mar 05, 2018 determination of free swell index of soils 1. Methodology swelling tests in model tank the soil sample of height 80 mm was compacted corresponding to maximum dry density and optimum moisture content in a mould of dia 150 mm and height of 180. Free swell index, yes we will learn this important soil test in this video, for more detail visit our website follow us o. Swellconsolidation characteristics of fibrereinforced. The shrinkswell index of clay refers to the extent certain clay minerals will expand when wet and retract when dry. Prediction of swelling behavior of expansive soils using. If the free swell index of a soil is more than 100, the soil may be expansive.
For the soil samples index properties are calculated and soils are classified accordingly. In an effort to extend the knowledge about the mechanical behavior of clays in this part of barranquilla, this. The modified free swell index is shown to bear unique correlations with liquid limit volume basis and percent swell of oedometer specimens compacted to proctor optimum conditions. D653 terminology relating to soil, rock, and contained fluids d698 test methods for laboratory compaction characteristics of soil using standard effort 12 400 ftlbfft3 600. Oedometer swell test the time versus swell response of the soils was obtained. Crucible swelling index, also known as free swelling index, in coal assay. To realize foundaiton distress, the swell pressures have to exceed the foundation stress. It consists of pouring slowly 10 cm3 of oven dried soil passing a 425mm sieve into a 100 cm3 measuring jar. Im just not sure how you convert free swell into a. The free swell is then reported as the increase in the volume of the soil expressed as a percentage of the.
Free swell index soil applied and interdisciplinary physics scribd. No doubt, the free swell test will give you some measure that the soil is prone to swell. Atterberges limits, free swell index, swelling pressure, c. Bentonite swell index astm d5890 global synthetics. Data required for modeling were collected f rom the literature 312. The process began with the selection of input parameters and the output parameter. Swelling properties of expansive soils treated with. Estimation of swell index of fine grained soils using. The determination of free swell index also known as differential free swell of soil helps to identify the potential of a soil to swell which might need further detailed investigation regarding swelling and swelling pressures under different field conditions. Characterization of the swelling properties of highly plastic. Definition soil swelling is a term generally applied to the ability of a soil to undergo large changes in volume due to increased moisture content. Expansive soil, swelling potential, methylene blue test, modified. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. Subbituminous coals and lignite are classified as free burning coals.
Free swell is 2720 part 201977 experimentation all experiments were carried out from engineering point of view to identify the reduction in free swell index and to improve the engineering properties of black cotton soil. Free burning coals do not have the same swelling characteristic free swelling index of 0. Free swell index fsi indicates the potential expansiveness of a soil. Prediction of fsi value by using hyperbola method international. Engineering correlations for the characterisation of reactive soil behaviour for use in road design a dissertation submitted by. The swelling index stays constant after addition of 8. In this method, the free swell index is defined by the eq. There is still a great necessity for civil and geotechnical engineering practice in the city to deepen the understanding of the mechanical properties of the soils in this zone of the city. Traditional freeswell testing to achieve the same level of characterization required approximately 30 days for the highly plastic clay evaluated in the study. The level of the soil in the distilled water cylinder shall be read as the free swell level.
The timeswell response of soils follow rectangular hyperbola. In order to determine the relationship with the highest regression coefficient between the index parameters and swell index, regression analyses were performed between w n, ll, e 0, g n, g d and swell index. The free swell index of the soil shall be calculated as follows. May 20, 2018 free swell index, yes we will learn this important soil test in this video, for more detail visit our website follow us o. The possibility of damage to structures due to swelling of expensive clays need be identified, at the outset, by an investigation of those soils. Standard test methods for onedimensional swell or collapse. Determination of free swell index of soils slideshare. Equipment apparatus oven1050c to 1100c, min balance 0. Parameters such as cbr swell, shrink swell index, soil suction, weighted plasticity index, swelling pressure, weighted linear.
Correlation between swelling index of bentonite clay and. Engineering properties of bentonite stabilized with lime and. What is the procedure for free swell index test of soil. They concluded that the soil clusters became larger and that binding with ohled to formation of floccules resulting in the. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to.
The level of the soil in the kerosenegraduated cylinder shall be read as the original volume. The test results indicate that, the free swell index linear variation with the non swelling residual soil. Free swell index is the increase in volume of a soil, without any external constraints, on submergence in water. In this method 10 grams of ovendried soil sample passing. Freeburning coals do not have the same swelling characteristic free swelling index of 0. The content of the lime and phosphogypsum varied from 0 to 10 %. Free swell is the increase in volume of a soil, without any external constraints, on submergence in water. If the free swell index is lower than 100, the soil may be treated as nonexpansive.
Free swell index test is conducted by taking 10g of oven. Objective for determination of free swell index of soils reference standard is. In this video we will learn how to determine the free swell index of soil. Determine free swell index of soil civil engineering. Standard test method for expansion index of soils1 this standard is issued under the. The plots were drawn for the training and the testing data of the ann model and were shown in fig. If a soil does not contain any clay fraction, it cannot be expansive.
The soil samples, kerosene being a nonpolar liquid does not cause swelling of the soil. Procedure soil sample upto 500 gram is taken from desired site and kept in oven for 24 hours at 1001100c, so that sample becomes. Free swell index test of soil, fsi test of soil asper is code. Free swell will overstate the extent of the swelling. Soil with a high shrinkswell capacity is problematic and is known as shrinkswell soil, or expansive soil. Atterberg limits, grain size distribution, optimum water content, maximum water content, swelling pressure, methylene blue value mbv, vi modified free swell index mfsi and swell potential of the mixtures were assessed. Artificial neural network the methodology used for modeling the prediction of the free swell index of the expansive soil using a neural network has been presented in this section. The maximum swelling index of 16ml2g occurred after the addition of 9. The measure of swell used by the corps of engineers is termed the free swell index. The swelling pressure increases as the free swell index increases.
Input parameters for the artificial neural network model were plasticity index and shrinkage index, while the output was the free swell index. The swell index or free swell test procedure is used to determine the general swelling characteristics of sodium bentonite clay. Engineering properties such as compaction, unconfined compressive strength, consistency limits, percentage swell, free swell index, the california bearing ratio and the consolidation of bentonite stabilized with lime and phosphogypsum are presented in this paper. Free swell or differential free swell, also termed as free swell index, is the increase in volume of soil without any external constraint when subjected to submergence in water. The expansive soil specimens were prepared in the laboratory by mixing kaolinite and bentonite at different percentages. As the clay percentage in a soil increases, it exhibits more swelling pressure and free swell index. Swelling index may refer to the following material parameters that quantify volume change. The purpose of this study is to compare the performances of widely used empirical swell index equations and to develop new empirical equations and a neural network based estimation technique for swell index by using the results of conventional oedometer and index test results. The index properties of the soil are presented in table 1. In this paper, a nondimensional modified free swell index is proposed, which removes the uncertainties present in the holtz and gibbs method. Pdf prediction of free swell index for the expansive. This method allowed for the characterization of the swelling properties of the soil within 24 hours of the start of testing. Determine free swell index of soil civil engineering portal. May 14, 20 objective for determination of free swell index of soils reference standard is.
Experience has shown that the plasticity index pi is an excellent indicator of. A number in parentheses indicates the year of last reapproval. Swelling properties of expansive soils treated with chemicals. The loadinduced strains after wetting from test method c can be used to estimate stressinduced settlement following.
Plasticity index pi, free swell index fsi%, swell potential and. Characterization of the swelling properties of highly. Prediction of free swell index for the expansive soil using. Another additive that as been found to be quite promising in reducingh the swelling characteristics and improving the engineering behavior of expansive soils. To determine the free swell index of soil as per is.
Modified free swell index for clays astm international. Expansive soil was collected at a depth of 1 m from the ground level from the town of amalapuram, ap, india. For highly plastic soils the nature of curve of free swell index versus swelling pressure is upward concave while for low plasticity soils it is downward concave. Soil shrinkage characteristics in swelling soils 477 methods for assessing soil swellshrink potential a coefficient of linear extensibility, cole it characterizes the variation of soil volume from atm water retention i. Free swell index test, swelling pressure test, swell percent. Prediction of the free swell index of the expansive soil using artificial neural network has been presented in this paper.
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