Analysis of Soil Permeability Reduction Using Cement and Fly Ash

This project focuses on reducing the permeability of soil, particularly collapsible soils found in arid regions, by using cement and fly ash. The research involved collecting soil samples from Al Ain and Sharjah in the UAE, conducting grain size analysis, and performing constant head permeability tests. Different percentages of cement and cement-fly ash mixtures were added to the soil samples at varying densities to assess their impact on permeability. The study aimed to prevent structural damage, reduce soil shrinkage and swelling, minimize the space between soil particles, and decrease the settlement of structures. The project includes a literature review, detailed methodology, analysis of the results, and discussion of the applications and future work. The findings highlight the effectiveness of cement and fly ash in improving soil properties and enhancing the stability of construction projects in areas with problematic soil conditions. The project also includes cost analysis and provides a conclusion summarizing the key findings and their implications for civil engineering practice.

REDUCTION OF PERMEABILITY OF SOIL
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ABSTRACT
The knowledge of soil structure is very crucial as far as building and construction is
concerned. Engineers rely on this particular knowledge to facilitate erection of structural stable
buildings and infrastructure. This particular paper focused on the study of the collapsible soil
(sand) characteristics and how their property of permeability can be improved through fly ash
application as well as cement addition. When using this test then it was considered very
important to perform as many replicate experiments as possible so to ensure that the observed
effect was the real and could be the basis of drawing conclusion. The equivalent or the average
permeability coefficient of the sand deposit commonly abbreviated Keq, was found to entire rely
on the flow direction in relation to the bedding plane orientation. The study further indicated that
addition of the fly ash also improved the permeability of the sand soil and silt by decreasing the
ratio of the voids.

Contents
ABSTRACT....................................................................................................................................................2
INTRODUCTION...........................................................................................................................................3
Background..............................................................................................................................................4
PROJECT DETAILS.....................................................................................................................................6
Roles and Responsibilities.......................................................................................................................8
Project Risk Assessment......................................................................................................................9
LITERATURE REVIEW....................................................................................................................................9
METHODOLOGY.........................................................................................................................................17
CEMENT AND FLYASH ADDITION...............................................................................................................18
Cement..................................................................................................................................................18
Flyash.....................................................................................................................................................18
PROJECT ANALYSIS AND FEASIBILITY.....................................................................................................19
RESULTS ANMD DISCUSSION.....................................................................................................................20
Results...................................................................................................................................................20
Samples with added cements and flyash...........................................................................................20
Samples without Cement and Flyash addition...................................................................................21
Discussion..............................................................................................................................................21
APPLICATIONS...........................................................................................................................................22
FUTURE WORK...........................................................................................................................................24
COST ANALYSIS......................................................................................................................................24
CONCLUSION.............................................................................................................................................25
REFRENCES................................................................................................................................................26

INTRODUCTION
One of the most engineering properties of the soil is the capacity to allow for the passage
of different kinds of fluids via the interconnecting voids present in it. As far as the branch of
science called soil mechanics is concerned, the study of soil permeability is very crucial aspect.
It is through such kind of the studies that the quantity of the underground passage or seepage
under various hydraulic situations is uncovered. In such studies, one of the key factors that have
been targeted is the coefficient of permeability whose value is obtained by the permeability test
of constant head. The constant is use in the calculations of the stability, filtration drainage and
finally settlement determination (Milunović et al 2017).
The above highlighted challenges are very important aspect of the environment when it
comes to control of the slope stability, management of waste water as well as the failure of
structures in relation to settlement issue s of the ground. The water movement as well as drainage
in any fine-grained soil have been treated as the main primary vital as fat as the study of soil
science, geotechnical engineering and hydrology is concerned. In the geotechnical engineering
field, there is significance influence of the permeability on the soil consolidation characteristics
alongside mobilization of the soil shear strength. This is because it is a consequence of the soil
drainage. Also the study of the sand seepage, flow of groundwater, problems of the slope
stability and other relevant topics will always need reliable information of the fine-grain soils
permeability properties.

In the case of the layered system of the soil, the bedding planes of such kind of the layers
can be either in vertical or horizontal or in extreme cases inclined. When this happens, every
layer will be expected to have its own coefficient value of the permeability commonly marked as
constant, K. The equivalent or the average permeability coefficient of the stratified deposit
commonly abbreviated Keq, will entire rely on the flow direction in relation to the bedding plane
orientation. The possible flow to be identified include: A flow which is parallel to the direction
of the soil and flow which appears to be perpendicular to the layer.
The other geological problems which are common are the dispersion, expansion as well as
collapsibility of soil. This simply implies reduced or inadequate bearing capacity of such soils.
The moisture sensitive soils or collapsible soils are characterized by high moisture content to the
extent that very little introduction of water contributes to the destruction of the soil particle
structure. In fact such will start to fall even before they become saturated fully. Such poor
characteristics of the sand soil are associated with the destruction of the structures in certain parts
of the UAE. The soil is therefore refered to as problematic types of soils. This particular project
has tried to analyses the permeability of the soil in selected areas of Al Ain and Sharjah through
scientific research methods that which included the prescribed test before presenting the facts as
they were.
Background
One of the basic properties of sand which actually deserves proper investigation is permeability.
This particular property was investigated both in the field and through comprehensive laboratory
work. While solving some of the geotechnical problems, the accurate knowledge of the
permeability property is very crucial. This should be determined with economically margin of

the reliable safety. There has been recognition of at least three categories of the problems
terotechnology where the data on the permeability is very essential including:
 Water retaining structures and dams
 Earth structures settlements on the deposits of the soft sand and silt soil over the world
 Problems of the environment as related to the hazardous as well as toxic disposal of
wastes.
One such practical example considered crucial as identified by the scholars is the impact
that the structure has in the case of the newly generated dam. In such studies the dam is treated as
very unique features of the geography. It is usually characterized by the creation of the large
hydraulic gradient. The research that had been conducted on similar structure was clear in the
illustration of permeability reduction in the sections of the foundation especially in the ratio
approximated to be 102.
This process actually led to the development of the creation of the underground barrier to
the hydraulics. On this particular barrier, there was concentration of the seepage action which
contributed to the system failure. This failure was through sliding of the foundation of the dam
along the fault found under the structure .The large structures natural foundation as well bas
man-made rock slopes are usually subjected to the water flow which is subsurface. Such flows
are closely linked to the natural conditions of hydrological circumstances including rain.
Some of these conditions like the floods of the river are very dangerous in terms of the
consequences considering that they are usually hard in the prediction index. In similar cases, the
hydraulic gradients are usually small as compared to those which have been induced by the
constructed structure s like the dams. One of the important aspects of the operation of these kinds

of the processes is that they are responsible for the generation of the forces that have the same
order of magnitude. Such magnitude of forces nearly resembles those acting on the masses as a
result of the gravitational impact.
Although there is a requirement of the proper analysis of the hydraulic barrier beneath the
structures on sand or silt soil, the results should be used for the future analysis of the impacts of
the properties of the soil when constructions are to be done.
PROJECT DETAILS
Goals and Objectives of the project
Aims and scope of the Research
The research work had the following general aims:
 To reduce swelling and shrinking of the soil samples under study
 To effectively prevent structure damage
 To achieve space reduction between soils which is collapsible
 To achieve crack reduction in the boundary walls which are consequences of
shrinking
Scope Definition
 Undrained Shear
There was considering of a single type of sand soil which had permanent water. This was
followed by the adoption of various experimental procedures in setting up the testing of
permeability starting from the form of slurry. The recent years has been characterized by several
attempts of the permeability testing. These testing have been artificial. They have involved the

use of liquid wastes as permeants besides traditional techniques of using water. The use of
different types of permeants on the soil samples subjected to the multitude histories of stress was
in attempts to duplicate the possible conditions of the silt and sand. Unlike other types of soil, the
permeability data of sand is expected to be greater than 1x10-7m/s for the effective establishment
of reliable decision of the support.
Constraints
 Accessibility to specific sites with unique soil characteristic was one of the major
challenges
 Project was relatively expensive
This particular research is actually concerned with the permeability measurement of the samples
of the silt and sand to properly investigate permeability development.
Project Management Approach
The project employed the synthesis approach whereby every stage or step was allocated its
sufficient period for the delivery.
Project Timeline

March
2019
April
2019
May
2019
June
2019
July
2019
August
2019
September
2019
Research and Preliminary Studies
Literature review
Proposal Writing
Class Presentation
School Presentation
Material Acquisition
Experimental work
Set up and Testing
Additional modification
Final Report Write Up
Final Presentation
Roles and Responsibilities
Provision of the most effective manner of soil permeability study

Project Risk Assessment
LITERATURE REVIEW
The technique in which the water flows past a porous soil material is very vital in the study of
soil mechanics and it:
 Includes the total volume of flow of the water past the soil particles, that is, the sand and
silt dam leakage determination.
 Includes the foundation settlement rate
 Includes the strength, that is, determining safety embankment issues
The flow of water in the soil does not follow any given formula from point to point with the
velocity being constant but in various directions of the soil pores. Bernoulli in his equation stated

that the sum of velocity head, elevation head and pressure head gives the total head at a
particular point of the flowing water(Lara et al 2017).
Where Pw/y= the fluid pressure head of a given unit length
V2/2g= fluid kinetic or the fluid velocity head of a given unit of length.
Due to the small velocities of the flowing water, the elevation head and the pressure head re also
small and therefore velocity head can be assumed.
Z= elevation head with regard to arbitrary datum. This is the measure of distance between the
datum and the head. in case the point appears to be under the datum, the value is negative and is
positive when the datum is below the point. This results into the formula below:
In which i= gradient of the hydraulic
L= length of flow past which head loss occurs
Darcy's Law:

The law mainly covers the flow velocity discharge in a saturated soil and can be expressed in the
formula below;
V=Ki
In which K is the coefficient of permeability in cm/s and V is the superficial or discharge
velocity.
Usually in determining the discharge velocity, it is assumed that;
-there is no friction between the joints
-the saturation of the soil is at its maximum
-the fluid is in laminar type of flow in which the number of Reynolds is less than one
In which v is the velocity of discharge
D10 is the effective diameter of the soil
~s is the water dynamic velocity
The flow of water past the molecules of the soil results into seepage forces or the drag forces on
the grains which alters the flow direction and at the same time alters the pressure of the pore
water and soil effective stress.
The value K which is the coefficient of permeability is determined by;
 shape of the soil particle