Computers and Geomechanics: Slip Line Theory in Retaining Walls

This report provides an in-depth analysis of computational geomechanics, specifically focusing on the application of slip line theory to retaining walls and unsaturated soils. It explores the importance of numerical analysis in geomechanics and discusses the computational framework, numerical methods, and the suction method for soil analysis. The report examines the features of the computational framework, including experimental campaigns and numerical simulations, along with other methods like effective stress and soil interface models. It delves into governing equations and the retaining wall problem, comparing the suction method with other techniques, highlighting its advantages in terms of stability, convergence, and adaptability. The conclusion emphasizes the need for incorporating computational geomechanics and the importance of testing and proof testing methods to achieve accurate results, especially when using the suction method and other methods together, to find the best method for project managers. The report references various sources to support its findings.

Computers and Geomechanics following Slip line theory applied.

Computers and Geomechanics following Slip line theory applied.
Executive Summary
This report shows the major importance of Numerical analysis in Computational geomechanics with
computers in slip line theory applied that has been to a retaining wall–unsaturated. The process whereby
soil and rock mechanics use to investigate subsurface conditions and materials so that they can come up
with appropriate physical, chemical or mechanical composition of these materials is known as
computational geomechanics. The mechanics also use it, computational geomechanics, to check the
stability of slopes made naturally and those made by man. At the end, there will be an investigation of the
performance of numerical between one dimensional finite schemes and several mesh procedures with
time stepping algorithms.
The report will also describe the computational framework/numerical model proposed and its main
strength and limitations, the report will compare different numerical methods developed to study the same
computational geomechanics. At the end, there will be a comparison of the model done with other works
in literature.

Computers and Geomechanics following Slip line theory applied.
Table of Contents
Executive Summary.......................................................................................................................................2
Introduction....................................................................................................................................................4
Computational Framework/ Numerical Method............................................................................................4
Main features of Computational Framework.................................................................................................4
Other methods................................................................................................................................................5
Effective stress...........................................................................................................................................5
Soil and Interface model............................................................................................................................5
Governing Equations.................................................................................................................................5
Retaining wall Problem..............................................................................................................................5
Comparison of Suction method and other Methods......................................................................................6
Conclusion.....................................................................................................................................................7
References......................................................................................................................................................8

Computers and Geomechanics following Slip line theory applied.
Introduction
There is a need for Project Managers to properly understand different theories and analysis that are used
to evaluate soils and foundation designs. The extensive Computational geomechanics is a wide study that
helps mechanics in their day to day study of soil and rocks, learning their features and soil composition.
In this report, we are looking at a study of in geometric whereby slip line theory has been applied to a
retaining wall–unsaturated soil so that it can be applied to solve soil interaction problem. An extensive
study of soil and its behaviors, on unsaturated soil, whereby it is presented and applied to a rigid wall that
is rotating into unsaturated soils. A properly managed study of the phenomenon of slip line theory that
has been applied to solve the problem of to a retaining wall–unsaturated soil in soil suction, must have
effective results. There are many methods used to deal with earth pressure. However both methods are
good and give estimated results. The finite and domain. Computationally, Differential Equations governs
slip line theory. In this case the soil is in the unsaturated form. The method of Suction is then introduced
to the soil strength and stress state using the idea that is effective of stress. (Reddy, 2010)
Computational Framework/ Numerical Method.
According to (Hao, 2008)Computational framework is the basis of observing chemical processes
reactions in the soil. In the research method of slip line theory that has been applied to a retaining wall,–
unsaturated soil analysis of two phase saturated suction method, computational framework/numerical
model is suction. Suction in this case is influenced with different factors such as soil type and soil
structure. This method is usually used in engineering and mathematical physics to come up with solutions
of numeric. This approach have its own limitations. Since the soil is more rigid, the process of increment
and absolute strain ratios are usually the same. Also the level of assuming the non-coaxially, in case
additional kinematic constraint needs to be specified and therefore the displacement analysis might lead
to a higher complication. (Athanasios and Thomas, 2010)
Main features of Computational Framework.
One of the features of the suction is experimental campaign. This is where drafts are made and lab tests of
suction bucket foundation in sand. Many test experiments are carried out, then an estimate is chosen.
Another feature of the computational framework is using numerical model in suction. This is where
simulations sequences and Lagrangian and combined Lagrangian models are used. Specific results are
always obtained. No estimates. (Celebi, Goktepe and Karahan, 2012)
The third feature in the suction method is numerical simulation method.

Computers and Geomechanics following Slip line theory applied.
Other methods
Effective stress
In computational geomechanics, the force that keeps collection of particles is known as Effective stress.
Mostly it applies to most kind of soils namely sand, soil, or gravel. We see that the importance of
effective stress was discovered by Karl Terzaghi. (Lutz, 2007). This stress in the soil is passed through
small particles through the mass of the soil at the point of its contact. In other words, this is also known as
the inter-granular stress and denoted by σ’. Compression of the soil mass may be incurred when there is
greater resistance than the grain resistance, after soil has been loaded. This compression is usually caused
by the elasticity of the grains where there is physical or chemical connectivity or contact. Therefore,
effective stress best describes this load per unit area of the soil mass. The major advantages of effective
stress is the roles it plays in soil, namely shear strength of the soil and soil settlement.
Soil and Interface model
Mohr-Coulomb study is usually used in this model, here both unsaturated and saturated soil wall interface
are used. At soil model and interface model, there is assumption during calculations the friction of the
angle is mobilized at every point in the where there is unsaturated soil. Mostly the greatness of the friction
of the angle can be significally be greater.
Governing Equations
Governing equations is whereby, mass is conserved and energy too is conserved in fluid. In wave
propagation analysis, the porous media can be compressed with viscid fluids.
Infinite Element Formulation
This is where shape decays with distance and zero is reaches infinity. The shape functionality does not
matter a lot here. This methods consists of two main steps whereby, there is need of analytical
identification solution of the problem and derivation of the shape from it. This method in cooperates
several solutions.
I.D analytical approach is one of the solutions of the infinite element foundation whereby element
functions shapes are derived from it. Shape functions is another type of infinite element solution whereby
the shape functions are the key elements. Property functions is another approach whereby all directions
are shown. (Joonsang, 2012)
Retaining wall Problem
Retaining wall problem commonly have four parts, which are intense inspection, demonstration of the
results, testing and analyzing the findings. In inspection, the common methods used are usually the five
senses which are tasting, touching, seeing, smelling or olfactory. (Jien and Andrew, 2012)This is used to
identify the accuracy and efficiency of the in Suction during slip line theory that is usually applied to a
retaining wall–unsaturated soil analysis. Two experiment are carried out and then they are compared to
verify the similarities. Example, a problem with 1D problem that consists the form of saturated porous
media that has been subjected to a uniformly harmonic loading with frequent circular frequency. A
diagrammatically presentation of the task and the suction the near the immediate field is discretized using

Computers and Geomechanics following Slip line theory applied.
the formula of eight-node isoperimetric. A good example of RWP is a typical wall is that is used for
experiment. We are going to imagine that the wall is 5 m high, we have unsaturated soil and water is 10m
below.
Comparison of Suction method and other Methods
Theoretically suction method has more advantages compared to other methods on calculating unsaturated
soils. The most known advantage is stability. (Karl and Ralph, 2013). Moreover suction method is more
stable compared to the other methods and easy to establish. It is good to know prior so that one will not
use it unknowingly.
Convergence is another advantage of Suction because variation forms usually are consistent with
governing equations. The approximation of Suction usually follows from best approximate results.
The Suction is easily adaptable thus making adaptivity the third advantage of Suction over the others.
This is where you have to rely on indication and not estimation. The other method show where error
might be and not the exact place.
Computationally, Suction also has some advantages as listed below,
Hybridization this is where the mixed formulation method is used, where you use second order term as
systems of two first order terms.
Inhomogeneity this is when one used higher order quadrature rule in Sanction naturally.
Complex geometrics, this is where in Suction is used to solve problems theoretically given that one has a
good mesh generator, without changing a code.
Boundary conditions, this is whereby finite element method is used to resort conditions that are
considered weak.
With the above comparisons, of suction model of unsaturated soil, over the other methods, the advantages
make the method seem to be the most efficient method to use in the testing’s. (Delwyn and Murray, 2012)

Computers and Geomechanics following Slip line theory applied.
Conclusion
In conclusion, slip line theory that has been applied to a retaining wall–unsaturated problems of the soil
have been fully analyzed and it is seen that that have saturated the soils in great way. This includes
domains that are unbounded. Computational geomechanics should be incorporated more and many
approaches used to come up with an accurate answer or method. Application of the element is discussed
into length to show efficiency of the proposed element. The Suction may seem to be the best, but keeping
in mind the other methods too are all well perceived. The main aim is to come up with a better method
that will give accurate results irrespective of the shape of the soils or surfaces. To conclude, when the two
methods are in cooperated or used together, they tend to bring out accurate results, until when elements
are introduced and then the numerical results seems to disappear. For project managers to come up with
the best method, they need to test and proof test the method and finally use the one that does not strain, or
limit them in any way possible.

Computers and Geomechanics following Slip line theory applied.
References
Athanasios, P., & Thomas, B. (2010) Soil Engineering. Berlin: Heidelberg.
Braja, M. (2016) Principles of Foundation Engineering. Australia: Cengage Learning.
Celebi, E., Goktepe, F., & Karahan, N. (2012) Non-linear finite element analysis for prediction of seismic
response of buildings considering soil-structure interaction. Copemicus GmbH.
Delwyn, G., & Murray, D. (2012) Unsaturated soils mechanics in engineering. Hoboken, N.J: Wiley.
Hao, L. (2008). Diffraction of SH-waves by surface or sub-surface topographies with application to soil-
structure interaction on shallow foundations. Los Angeles: California.
Jien, H., & Andrew, J. (2011) Advances in geotechnical Engineering. Reston: VA
Joonsang, P. (2012) Wave motion in finite and infinite media using the thin layer method.
Karl, T., & Ralph, B. (2013) Soil Mechanics in Engineering practice. England: Read Books Ltd.
Lutz, L. (2007) Wave propagation in infinite Domains: with applications to structure interaction.
Dordrecht: Springer.
Reddy, R. (2010) Soil Engineering. New Delhi: GeneTech Books.
Rodney, L. (2013) Soil and Water conservation engineering. St. Joseph: Mich.
Sunjay, K. (2017) Fundamentals of Fibre-Reinforced Soil Engineering. Singapore: Springer Singapore.