Geotechnical engineering issue — mishary Essay Example

GEOTECHNICAL ENGINEERING ISSUE-MISHARY. 13

Geotechnical Engineering Issue-Mishary.

Geomechanics in excavation and
foundation works.

Theinvestigation/ reviewtopic.
The
excavation of construction
phase helps
lay the
structural
foundations. However, various
soil geotechnical soil properties
influence the
excavation and
foundation work
and the
ultimate strength of the structure. The soil/rock
properties
influence the
extent and
type of excavation
required for
the specific
structures. Different
properties also
affect the
mechanisms of landslide
disasters in foundation and
excavation
works
.Theoutline of theprojectreport.

Geomechanics in excavation and
foundation
works
.The
soil properties that influence
the excavation
work and
the foundation
systems include
structure, texture, porosity and permeability. Additionally, other
soil properties that influence
the excavation
and the
foundation system
construction
include liquid
limit, plastic
limit, soil
densities and
shrinkage
characteristics. These factors
affect the lifespan of the
foundation
systems as well as the types of columns
suitable for
the specific
types of foundations
.Responsibilities of a geotechnical engineer In
.foundation and
excavation as well as building
construction, the
responsibilities of the geotechnical engineer
include
assistance of the displacement and
the resettlement activities
associated with the project. Besides, he/she should engage in the development of the sustainable engineering
designs. Moreover, he/she
acts as a player in the environmental management
Principles of sustainable design and development.
.The
principles of design and
development for
use in foundation
and excavation
work include
designing with an aim to create
durable
structures with manageable lifespan. Besides, designing and
development with the aim to create a sustainable project should also have
plans for
the structural
afterlife. Moreover, the
design/development
practice needs to embrace the
product
flexibility as well as agile
processes
.Suggested
investigation
areas
.The
suggested areas of research are the
classification of the types of foundations according to the
soil
properties
.Foundation
system of Prima Pearl Tower (ground
improvement, land
development, land
reclamation
work Prima Pearl Tower
)was
completed in June 2014, and the
foundation work
faced such
challenges as high water
table and
difficult soil
strata. The
ground
improvement of the foundation
system included
the construction of the retaining
walls as well as the use of jet grout columns
.Mechanism/cause of landslides in excavation works
and foundation
systems
.The
cause of landslides in excavation and
foundation
systems include
water, seismic waves and
mechanical
vibrations caused by the excavators. The
occurrence of landslides in excavation and
foundation works is more probable in sloppy
areas.
Mechanisms of failure of foundation
systems
.Failure of the foundation
systems is caused by high
rates of evaporation, low
soil drainage, poor ground
preparation as well as poor
soil compaction. It can also
result from leaky
plumbing. Failure of foundations
happens due to foundation
settlement, cracks and
gaps in the
system
.Remedies
for foundation
systems
failures
.The
foundation
failures can be remedied through watering, soil
testing prior to foundation
works, use of compressors to compact the
soil. Besides, it can be avoided by the employment of the standard
plumbing
practices
.Investigation report.

Geomechanics in excavationandfoundationworks.
Excavation is one of the
initial phases of both surfaces
and underground
structures. Excavation work
varies with the
type of oil
or rock
and their properties. Such geotechnical soil
properties that influence
excavation
include
structure, texture, porosity and permeability. Extra-fine soil
structure
characterizes the
clay soils, and the
excavation work
for that
class of soil
includes drainage
excavation before setting up a foundation system of the work (Handy & Spangler, 2007). Soil
structure
influences the
amount of empty
spaces in the
soil and
thus such
aspects as drainage, moisture content, and aeration. These aspects are important in engineering work as well as structure
foundation
systems. Soil permeability particularly
affects the
decisions abound
the foundation
systems because of the need to put up waterproofing mechanisms in highly
permeable soils in foundation
works as well as raising the
structural
columns (Hicher, 2012). On the
other hand, the porosity of the soil
influences the
soil mass’ strength. However, the porosity of the
soil is a product of the soil
structure, texture and
organic matter content.

The
index properties of the soil that influence
excavation works
and foundation
systems include
liquid limit, plastic limit, soil densities
and shrinkage
characteristics. These properties, also known as Atterberg Limits, are assessable in the
laboratories for
the fine-grained soil classes (Hicher, 2012). Other geotechnical aspects that influence
foundation
systems and
excavation works
include friction
angles of the
soil heaps
and soil
cohesion and
have effects on the safety
recommendations to be followed in civil
engineering works (Handy & Spangler, 2007). Foundation
systems affect
the size, as well as the lifespan of a structure
and engineers, has a requirement to determine
adequately the geotechnical as well as geomechanical soil
properties before putting up various
structures
(Preview: Geomechanics and Tunnelling 4/2015, 2015).Responsibilities of a geotechnical engineer. Geotechnical
engineers have a wide variety of social, cultural, global and environmental responsibilities
surrounding the
excavation as well as foundation works. Structures that
place a need
for displacement of persons from their settlements
also place a need for resettlement of the
same individuals (Lancellotta, 2009). Displacement of individuals to pave the
way for
structural
developments
cause a set of social
disruptions. The
engineering
community has a responsibility to facilitate the resettlement of these
individuals where
necessary. If
the displaced
individuals depend on the
soil for
specific cultural
practices, the
engineering
community need to come up with a list of soil
properties that is favourable to the communities’ cultural
practices as well as the influence of such aspects on the favourite resettlement locations.
The
most significant global responsibilities of the geotechnical engineers in the excavation
and the
foundation
systems include
the sustainable design and
development of the structures to increase their lifespan. In this
face, the
engineers need to interpret the
research finding to come up with suitable
recommendations
for the
specific
structures (Lancellotta, 2009). Besides, they need to be part of the
research
undertakings to investigate the
suitable options of sustainable structural
design and
development. From the environmental management point of view, the
engineer has a responsibility to report as well as make
recommendations about the
findings of project’s environmental investigations. This
responsibility is shared with the
project’s environmental managers. Besides investigating
the environmental impacts, the geotechnical engineers
also have
the
responsibility to collaborate with other experts to provide
remedies to the
identified environmental issues. Additionally, these
engineers are involved in drafting the
standard
operating
procedures for
use in the
work environment
in order to prevent environmental degradation. Furthermore, they
also provide
the necessary
technical support to the environmental litigation
and remediation projects, such as regulatory applicability and remediation system
design
(Lancellotta, 2009).Principles of sustainable design and development.
The traditionally developed
and designed
engineering works
do not have
effective
approaches to addressing all
facets of the
built industry
needs. However, most of the
engineering
projects
developed towards and in the 21st century have
consideration of the principles of sustainable development (American Society of Civil Engineers, 2004). One of the sustainable design
and development
approaches
necessary for
the excavation
and foundation
works is the guiding objective to establish a durable structure
rather than an immortal one. A
durable structure
lives to the targeted commercial
life without causing any
overwhelming set of environmental problems like bioaccumulation and
solid waste
disposal. If a structure is designed to have an immortal lifespan, it can result in the
accumulation of undesirable environmental hazards. A durable
structure allows
the employment of the minimal
techniques for
maintenance as well as the
introduction of minimal material to support the
foundation system (American Society of Civil Engineers, 2004).

The
second sustainable engineering
principle
applicable in the
excavation works
and foundation
systems are the
design for
the commercial
afterlife of the
structure. Since built environment
and engineering
practices are always changing, a point is reached where
the commercial
suitability of the structure
ends because of stylistic or technological obsolescence (National Concrete Masonry Association, 2010). At the end of the commercial
afterlife of the
structure, it is important to have a sound
plan to reuse the
remnants of the
obsolete
structure to enable sustainable development. Such a plan
reduce wastage of the remaining
valuable and
functional
component of the
structure. The
third principle of sustainable engineering
applicable to geotechnical engineers in excavation
works and
foundation
systems is the
product
flexibility and
the process
agility to meet
the need as well as minimize the excess (American Society of Civil Engineers, 2004). Besides, this principle
helps design with a consideration of the worst
case scenarios, modulate the
performance with an aim to address
the
unrealistic/extreme
conditions likely to be faced in the
project
.Suggestedinvestigationareas.
Foundation
systems’ success depends largely on
the soil
types, which influences the
type of the
foundation
constructed for
different
structures. That
notwithstanding, most of the
research work is diverted towards materials
and construction
methods of the
foundation
systems. It is, therefore, recommendable to commit
professional
resources in the
investigation of the soil in relationship to the types of foundation. The recommendable subsurface research
includes the
subsoil
conditions, number and
location of borings and the
suitable
properties for
specific
buildings. Besides, it is worthy
researching the
surface soil
properties and
classify them in terms of in terms of susceptibility to slides and water rise above the water
table (American Society of Civil Engineers, 2004). Finally, it is recommendable to establish a link between such soil
characteristics as compressibility and
plasticity to the
suitability of different types of foundation
systems
.Foundationsystem of Prima Pearl Tower (groundimprovement, landdevelopment, landreclamationwork)
The
technical
completion date of Prima Pearl Tower was June 30th, 2014. Prima Pearl seats in the precincts of Melbourne, Victoria. This
building has 72 levels and is 254 meters high
.The
foundation
system’s work and
the geotechnical aspects of the
building were
contracted to Frankipile Australia (Chapman & Stillman, 2014). This
building was
constructed in a challenging site, with high water
table and
poor soil
properties. The
soil composed of a large
deposit of soft
clay above a layer of basalt, stiff clay, sand and weathered siltstone at the bedrock. For the
contractor to lay
the foundation, a 10-meter deep
excavation below the water
table was
required to be propped by piles of the lift
core of the
structure. 22No 1800mm diameter
bored piles of 40m length
were used. In order to avoid
the collapsing of holes, the 1800mm span bored
piles were
penetrated under polymer (Chapman & Stillman, 2014).

Additionally, self-compacting tremie and
concrete
techniques were
applied to complete the
piles. For
the constructor to facilitate the
construction of the lift
core on the
project, the
jet grout columns (installed to as lateral base
slab) was
introduced, helping support
the secant load
wall cofferdam. At the depth of 20-22m, a 1-2m thick
stratum of Weathered Basalt placed a challenge but
heavy duty
augers and Fundex 3500 were
used to penetrate
the material. Other ground
improvement
methods used
for the
development of the Prima Pearl Tower’s foundation
system is the
construction of the retaining
walls within the
foundation to allow the
inclusion of the
basements, tanks, swimming pools
and retaining
walls (Chapman & Stillman, 2014).
Mechanism/cause of landslides in excavationworksandfoundationsystems.
Landslides are potential
risks in excavation and
foundation
systems’ work especially
if the
structure is to be constructed in sloppy
locations (Canuti & Sassa, 2013). Landslides
result in the
movement of rocks
and/or
soil due to gravitational pull
affecting the
natural slopes. The risk of landslides n foundation works as well as the
excavations
increases above normal in steep
locations with loose soil, seismic zones, intense weathering and
high rainfall, amongst others. As a result, landslides occur
because of the imbalanced relationship between the
external and
internal forces
acting on the
ground in such a way that
the destabilising
forces out-power the resistant
or stabilizing forces. In excavation and
foundation works, landslides happen in several
different
mechanisms. If
the foundation
system is to be erected in a rainfall-rich environment, the excavation
work and
water will work
together to cause
landslides (Canuti & Sassa, 2013). Excavation
work in wet
soil creates
soil instability
because of the
already existing
low friction
causing a downhill sliding of debris. If the
soil has fine
grains, a small
amount of water
increases
stability and
resistance to landslides. However, high
water content creates destabilization and a resultant landslide On
.the other
hand, if
the foundation
system is to be constructed in seismic zones, excavation works
increase the
risks of landslides. Earthquakes cause
the vibration of the earth’s crust, and
if the
crust already has weaknesses from excavations
any, the
friction
disruptions can cause a landslide can occur (Canuti & Sassa, 2013). Moreover, landslide can be caused by the
vibrations
emanating from the excavators. Some excavation
equipment cause high levels of vibrations
capable of causing local destabilization of the
crust. As a result, landslides can take place, and the
impact would depend on the
depth and
scale excavation. Such landslide
activities
associated with excavation
include sinkage
and subsidence. Sinkage happens in the
underground
cavities often without any
surface effect. In foundation
systems work, sinkage happens
if the
excavations
include
underground
tunnels. On the
other hand, the subsidence events involve
the slow sinkage of soils
because of the declining of the
water table as a result of the excavation
activities
.Mechanisms of failure of foundationsystems.
A
foundation system is designed to support the
surface
structures, and
it is a requirement to meet all the laid standards before announcing
the completion of the
foundation; otherwise it will fail to meet
the design expectations (National Concrete Masonry Association, 2010). There are several causes of foundation
failure and
if remedied
in a timely
manner success is achieved. One of the many
causes of failure in foundations
systems of buildings is evaporation. Evaporation is a result of hot
and dry
conditions that cause soil
particle to retract from the
foundation. Such
retraction causes
the imbalance of moisture of the foundation
and cracks may appear across the structure. Besides, if
the period of dryness is extended, there is soil shrinkage beneath the
foundation (National Concrete Masonry Association, 2010). As a result, gaps are created next to the
foundation. Foundation system
failure can also
result from plumbing leaks. Leaky plumbing
causes the
excessive water
and the
associated
erosion of the
soil that is supporting the
foundation. Besides, leaky
plumbing also
increases the
soil’s moisture content, and the
result may include
foundation
movement as well as the foundation
settlement. However, the
degree of foundation
movement is dependent on the
soil density as well as the
soil
type
.Foundation
failure can also
result from the
soil drainage. If the
soil is less well-drained, there is an associated
increase in the
moisture content as well as the resultant soil
erosion or
consolidation. Additionally, excessive
soil moisture may also cause
settlement or
upheaval. Poorly drained soil can also cause
soil oversaturation and
instability around the
foundation
systems (Brown, 2001). Foundation
failure due to poor drainage is irreversible
hence the
need to act proactively towards soil
drainage. Foundation
failure can also
happen as a result of poor
ground
preparation. Cut-fill practices that are widely
used when
building
structures can result in
poorly compacted soil underlying the foundation (National Concrete Masonry Association, 2010). The
failure
associated with poor soil compaction is caused by low soil
density and
soft soil. Besides, the
failure can also
result from the
water that seeps below the
foundation
because of lack of proper
diversion of water from the
structure. If
the building
site is poorly
prepared, the
soil is less
stable and
does not have
capabilities to stand any
unexpected
movements leading to foundation
settlement
.Remediesforfoundationsystemsfailures.
The
causes of foundation system
failure are widespread
creating a requirement for
the geotechnical engineers to have
remedial measures on standby. The
major cause of foundation
systems failure is evaporation (Brown, 2001). Evaporation due to extreme environmental conditions can be difficult to handle. However, some
practices can be applied to create
moisture balance in the soil
and reduce
soil shrinkage beneath the
foundation. One of the widely
applied practices is periodic watering of the
foundation system during the curing phase. It is recommended to assess the
soil for
such properties as porosity and
water retention to determine the
amount necessary to uphold the
soil moisture at the optimum levels to avoid
moisture over-saturation. After establishing
the water
retention
properties of the
soil, a watering program should be raised in order to
reduce the
creation of gaps
next to the
foundation (Brown, 2001). Nevertheless, building a structure in a soil that is capable of supporting the
optimum moisture levels is the
ultimate solution to the
evaporation
problems in the
foundation
systems
.The
failure of the
foundation
systems because of the leaky
plumbing can be mitigated through the use of technically high-quality plumbing
techniques. Apart from using high-quality plumbing
equipment, it is necessary to apply certified expertise. The
plumbing crew need use the
set standards to avoid leaky piping systems that can result in accumulation of water in the
faulty areas. The pipes
used in the
plumbing
activities should also be resistance to adverse
conditions of the
soil as well as have the
high durability to support a long leak-free life of the piping system (National Concrete Masonry Association, 2010).

On the other
hand, the
drainage causes of failure of the
foundation
systems can be remedied through drainage
excavation
especially if
the structure
borders a water
stream. This
practice reduces
the moisture content of the
soil surrounding
the structure. Remedies to soil
drainage need to be sought
earlier than the
commencement of the project
because they are inapplicable
if the
structure has been erected. Soil drainage
ensures that
foundation system
does not settle
because of the
soil over-saturation (Brown, 2001). Foundation
failures due to poor preparation of the building
site can be remedied through adequate soil stabilization before the
construction of the structure. Soil stabilization is achieved through compaction before using
the appropriate compressors. Finally, poor preparation of the ground can be remedied through soil grading to determine its structural
properties and
help establish
how to divert
water from the
structure.

References.

American Society of Civil Engineers. (2004). Sustainable engineering practice: An introduction. Reston, VA: American Society of Civil Engineers.

Brown, R. W. (2001). Practical foundation engineering handbook. New York: McGraw-Hill.

Canuti, P., & Sassa, K. (2013). Landslide science and practice: Volume 6. (Landslide science and practice.) Berlin: Springer.

Chapman, H., & Stillman, J. (2014). Melbourne then and now.

Handy, R. L., & Spangler, M. G. (2007). Geotechnical engineering: Soil and foundation principles and practice. New York, NY: Mcgraw-Hill.

Hicher, P.-Y. (2012). Multiscale geomechanics: From soil to engineering projects. London: ISTE.

Lancellotta, R. (2009). Geotechnical engineering. London: Taylor & Francis.

National Concrete Masonry Association. (2010). Design manual for segmental retaining walls. Herndon, Va: National Concrete Masonry Association.

Preview: Geomechanics and Tunnelling 4/2015. (August 01, 2015). Geomechanics and Tunnelling, 8, 4, 368.