Seminar abstract non seismic walls -مقاومة قوى الزلازل بالإطارات فقط واهمال ج...Dr.Youssef Hammida
Can we neglect reinforce concrete walls like stairwells, ele
vator shafts and so forth?
*And what are the behavior of these walls during the yielding
point for the steel in work stress stage uncracked section
[Elastic Response Parameters] and after the yielding point in
Plastic stage cracked section (Ultimate strength) since
*(Plastic Hinges) will occur in the Frames during plastic
stage And the frames shall peer all the entire seismic loads
And what are these Condition and arrangements to keep
the section walls in safety during plastic stage
so they can carry just the ordinary(D+L) axial loads.
Dose reinforcement for axial ordinary loads enough for these
walls from collapsing?
All these answers you will get it when you look at the Dis
sertation
Effect of non Seismic Walls
On Moment Resisting Frames in buildings.
Can we neglect reinforce concrete walls like
(stairwells, elevator shafts and so forth)?
*And what are the behavior of these walls during the yielding
point for the steel in work stress stage uncracked section
[Elastic Response Parameters] and after the yielding point in Plastic stage cracked section (Ultimate strength) since
*(Plastic Hinges) will occur in the Frames during plastic
stage And the frames shall peer all the entire seismic loads
And what are these Condition and arrangements to keep
the section walls in safety during plastic stage
so they can carry just the ordinary(D+L) axial loads.
Dose reinforcement for axial ordinary loads enough for these walls from collapsing?
All these answers you will get it when you look at the Dissertation
Comparative Study of Seismic Analysis of Building with Light Weight and Conve...Dr. Amarjeet Singh
In recent decades, the lightweight materials are used
in construction instead of conventional material. Lightweight
construction is considered to be favourable due to the saving
in construction cost and materials. AAC block is a lightweight
structural material with excellent acoustic and thermal
insulation properties. Due to the use of lightweight material in
construction in seismic zone reduce the percentage of
damages. In this paper the attempt has been made to carry out
the project comparative study of seismic analysis of building
with lightweight and conventional material. Structural model
of multi storey building (G+3) and analysis is carried out in
STAAD-Pro by RSM (Response Spectrum Method). Building
using infill AAC (Autoclaved aerated concrete) block and
conventional clay brick masonry are designed for the same
seismic hazard in accordance with the applicable provisions
given in Indian codes. The analytical results of the buildings
will be compared. The project is also aimed at getting
familiarity with STAAD-Pro.2008.
Seminar abstract non seismic walls -مقاومة قوى الزلازل بالإطارات فقط واهمال ج...Dr.Youssef Hammida
Can we neglect reinforce concrete walls like stairwells, ele
vator shafts and so forth?
*And what are the behavior of these walls during the yielding
point for the steel in work stress stage uncracked section
[Elastic Response Parameters] and after the yielding point in
Plastic stage cracked section (Ultimate strength) since
*(Plastic Hinges) will occur in the Frames during plastic
stage And the frames shall peer all the entire seismic loads
And what are these Condition and arrangements to keep
the section walls in safety during plastic stage
so they can carry just the ordinary(D+L) axial loads.
Dose reinforcement for axial ordinary loads enough for these
walls from collapsing?
All these answers you will get it when you look at the Dis
sertation
Effect of non Seismic Walls
On Moment Resisting Frames in buildings.
Can we neglect reinforce concrete walls like
(stairwells, elevator shafts and so forth)?
*And what are the behavior of these walls during the yielding
point for the steel in work stress stage uncracked section
[Elastic Response Parameters] and after the yielding point in Plastic stage cracked section (Ultimate strength) since
*(Plastic Hinges) will occur in the Frames during plastic
stage And the frames shall peer all the entire seismic loads
And what are these Condition and arrangements to keep
the section walls in safety during plastic stage
so they can carry just the ordinary(D+L) axial loads.
Dose reinforcement for axial ordinary loads enough for these walls from collapsing?
All these answers you will get it when you look at the Dissertation
Comparative Study of Seismic Analysis of Building with Light Weight and Conve...Dr. Amarjeet Singh
In recent decades, the lightweight materials are used
in construction instead of conventional material. Lightweight
construction is considered to be favourable due to the saving
in construction cost and materials. AAC block is a lightweight
structural material with excellent acoustic and thermal
insulation properties. Due to the use of lightweight material in
construction in seismic zone reduce the percentage of
damages. In this paper the attempt has been made to carry out
the project comparative study of seismic analysis of building
with lightweight and conventional material. Structural model
of multi storey building (G+3) and analysis is carried out in
STAAD-Pro by RSM (Response Spectrum Method). Building
using infill AAC (Autoclaved aerated concrete) block and
conventional clay brick masonry are designed for the same
seismic hazard in accordance with the applicable provisions
given in Indian codes. The analytical results of the buildings
will be compared. The project is also aimed at getting
familiarity with STAAD-Pro.2008.
Effect of Seismic Joint in the Performance of Multi-Storeyed L-Shaped BuildingIOSR Journals
The choices of building shapes and structural systems have significant effect on their seismic performance. While symmetrical buildings result in a fairly uniform distribution of seismic forces throughout its components. Unsymmetrical buildings result in highly indeterminate distribution of forces making the analysis and prediction more complicated. L-shaped buildings are among those unsymmetrical structures which are most commonly found in practice in the form of school, office, commercial buildings. In this work three dimensional models of L-shaped buildings are investigated for their seismic performance, varying bay length and storey height. These models were analysed for three conditions viz with gap, with seismic joint and with neither of these. The modeling of structures analysis is carried out using STAAD Pro V8i, also the performance is analysed providing brick infill and compared with, without infill condition. Performances is measured in terms of displacements, axial forces, bending moments, shear forces and compared for those conditions mentioned in the identified column viz., corner, intermediate and interior
Evaluation of the Seismic Response Parameters for Infilled Reinforced Concret...IOSRJMCE
RC frames with unreinforced masonry infill walls are a common form of construction all around the world. Often, engineers do not consider masonry infill walls in the design process because the final distribution of these elements may be unknown to them, or because masonry walls are regarded as non-structural elements. Separation between masonry walls and frames is often not provided and, as a consequence, walls and frames interact during strong ground motion. This leads to structural response deviating radically from what is expected in the design. The presence of masonry infills can result in higher stiffness and strength and it is cheap and built with low cost labor. Under lateral load, Masonry walls act as diagonal struts subjected to compression, while reinforced concrete confining members (Frames) act in tension and/or compression, depending on the direction of lateral earthquake forces. The main objective of this research is to develop a realistic matrix for the response modification factors for medium-rise skeletal buildings with masonry infills. In this study, the contribution of the masonry infill walls to the lateral behavior of reinforced concrete buildings was investigated. For this purpose, a five, seven and ten stories buildings are modelled as bare and infilled frames. The parameters investigated were infill ratio, panel aspect ratio, unidirectional eccentricity, bidirectional eccentricities. A Parametric study was developed on the behavior of medium rise infilled frame buildings under lateral loads to investigate the effect of these parameters as well as infill properties on this behavior
Under repeated impact composite domes subjected 6 J energy, changes locally with
increasing drop height. The action of the dynamic load generates reactions at the
support and bending moments at points on the surface of the composite. The peak loads
were noted to increase and stabilise about some mean value; and the 150mm diameter
shell was more damage tolerant compared to the 200 mm diameter one.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparative Study on Dynamic Analysis of Irregular Building with Shear WallsEditor IJCATR
South East Asia including Myanmar is situated in secondary seismic belt. Therefore, it is necessary to pay special attention of the
effect of earthquake in designing the high-rise building. Shear walls are very common in high rise reinforced concrete building. In this study,
comparative analysis of high-rise reinforced concrete irregular building with shear walls are present. The frame type of proposed building is
used the special RC moment resisting frame. It belongs to seismic zone 4. This is why, seismic forces are essentially considered in the analysis
of this building and shear walls are also provided to resist seismic forces. Structural members are designed according to ACI Code 318-02. The
structure is analysed by using ETABS v 9.7.1 software. Load consideration is based on UBC-97. All necessary load combinations are
considered in shear walls analysis and frame analysis. In addition wind load, seismic load is considered as external lateral load in the dynamic
analysis. In dynamic analysis; Response Spectrum method is used. In this project, study of 14 storey building is presented with some
investigation which is analyzed by changing various location of shear wall for determining parameters like storey drift, storey shear and storey
moment .
Effect of Seismic Joint in the Performance of Multi-Storeyed L-Shaped BuildingIOSR Journals
The choices of building shapes and structural systems have significant effect on their seismic performance. While symmetrical buildings result in a fairly uniform distribution of seismic forces throughout its components. Unsymmetrical buildings result in highly indeterminate distribution of forces making the analysis and prediction more complicated. L-shaped buildings are among those unsymmetrical structures which are most commonly found in practice in the form of school, office, commercial buildings. In this work three dimensional models of L-shaped buildings are investigated for their seismic performance, varying bay length and storey height. These models were analysed for three conditions viz with gap, with seismic joint and with neither of these. The modeling of structures analysis is carried out using STAAD Pro V8i, also the performance is analysed providing brick infill and compared with, without infill condition. Performances is measured in terms of displacements, axial forces, bending moments, shear forces and compared for those conditions mentioned in the identified column viz., corner, intermediate and interior
Evaluation of the Seismic Response Parameters for Infilled Reinforced Concret...IOSRJMCE
RC frames with unreinforced masonry infill walls are a common form of construction all around the world. Often, engineers do not consider masonry infill walls in the design process because the final distribution of these elements may be unknown to them, or because masonry walls are regarded as non-structural elements. Separation between masonry walls and frames is often not provided and, as a consequence, walls and frames interact during strong ground motion. This leads to structural response deviating radically from what is expected in the design. The presence of masonry infills can result in higher stiffness and strength and it is cheap and built with low cost labor. Under lateral load, Masonry walls act as diagonal struts subjected to compression, while reinforced concrete confining members (Frames) act in tension and/or compression, depending on the direction of lateral earthquake forces. The main objective of this research is to develop a realistic matrix for the response modification factors for medium-rise skeletal buildings with masonry infills. In this study, the contribution of the masonry infill walls to the lateral behavior of reinforced concrete buildings was investigated. For this purpose, a five, seven and ten stories buildings are modelled as bare and infilled frames. The parameters investigated were infill ratio, panel aspect ratio, unidirectional eccentricity, bidirectional eccentricities. A Parametric study was developed on the behavior of medium rise infilled frame buildings under lateral loads to investigate the effect of these parameters as well as infill properties on this behavior
Under repeated impact composite domes subjected 6 J energy, changes locally with
increasing drop height. The action of the dynamic load generates reactions at the
support and bending moments at points on the surface of the composite. The peak loads
were noted to increase and stabilise about some mean value; and the 150mm diameter
shell was more damage tolerant compared to the 200 mm diameter one.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparative Study on Dynamic Analysis of Irregular Building with Shear WallsEditor IJCATR
South East Asia including Myanmar is situated in secondary seismic belt. Therefore, it is necessary to pay special attention of the
effect of earthquake in designing the high-rise building. Shear walls are very common in high rise reinforced concrete building. In this study,
comparative analysis of high-rise reinforced concrete irregular building with shear walls are present. The frame type of proposed building is
used the special RC moment resisting frame. It belongs to seismic zone 4. This is why, seismic forces are essentially considered in the analysis
of this building and shear walls are also provided to resist seismic forces. Structural members are designed according to ACI Code 318-02. The
structure is analysed by using ETABS v 9.7.1 software. Load consideration is based on UBC-97. All necessary load combinations are
considered in shear walls analysis and frame analysis. In addition wind load, seismic load is considered as external lateral load in the dynamic
analysis. In dynamic analysis; Response Spectrum method is used. In this project, study of 14 storey building is presented with some
investigation which is analyzed by changing various location of shear wall for determining parameters like storey drift, storey shear and storey
moment .
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
1. SSUD13-311 Introduction To Structures
Answers:
Task 1 – Structural Design Principles
Question 1.1:
For each of the structural principles pictured, Figure 1, detail structural considerations
required for buildings during their design and service life. Please detail in your own words,
what each of these different structural principles are? And what they related to specifically,
using examples? Please use provided space as a guide for approximate word limit.
Figure 1: Structural Principles
Robustness- the term robustness means that any given structures should be able to
withstand an accidental or a territorial attack which may pop unreasonably.
A typical example is a case when the balcony glasses are made of brittle glass which shatters
into pieces in case of minor accidents, the user may live in fear in that he/she may thought
that every time the glass breaks there may be insecurities and may completely avoid using
the balcony.
Strength- strength of a material/structure is its ability to withstand any loading subjected to
it.
Example
Suppose the same balcony is designed to withstand a loading of 7 members of the family, it
would collapse when a house party is held and additional of 15 run towards the balcony.
This therefore means that strength is a key principle when making designs of structures.
Serviceability–this is basically the conditions in which the structure will be usable. An
appropriate design for structures should be at a position of performing a satisfactory
service loads. By doing this, it too shouldn’t cause any problem to the user due to cracking,
2. vibration etc.
Example
Basing a reference to the same balcony. Suppose the balcony has some visible cracks that
may have been caused by certain loadings, the user may completely avoid using the balcony.
By doing this, the balcony would have failed to serve the initial purpose it was constructed
for. Serviceability is therefore a key principle to be considered while developing structures.
Stability- the term stability is used when there is no rigid displacement or deformation to
the internal members of the structures. Stability can either be external or internal. Internal
stability is majorly concerned with the members of the structures while external stability
basically refers to with the members of the structures.
Example
Suppose the same balcony collapse when subjected to some loadings, the user may be afraid
to visit the balcony as it wouldn’t be stable any more. This would renders it weak and it
would have failed it purpose.
Question 1.2:
Define the following material properties
Ultimate stress
Ultimate stress is referred as the maximum stress that any given material can withstand
under the applied load
Hardness
Hardness- This is the resistance a material offers to a localized plastic deformation.
Harness to ranges from super hard materials to hard materials to soft materials. Super hard
materials include diamond and boron-carbide.
Question 1.3:
What happens to a material after it experiences a stress greater than its yield strength? Your
answer might benefit from the inclusion of a drawing.
In any case a yield strength is exceeded the stress-strain curve would continue to rise to a
maximum point. This maximum point is called the tensile strength point or the ultimate
3. stress.
If more loadings is again subjects to it wouldn’t reach the yield point and the curve would
returns to its original state.
Question 1.4:
Describe three (3) critical considerations related to material selection taking particular
consideration for the relevance to a project and the associated mechanical properties of the
material.
Mechanical properties. This include strength, ductility, hardness, fracture toughness and
also the impact resistance. In the design for a particular material, it should be able to
withstand any loadings. Therefore strength and stiffness is important
Wear resistance of the material.
Wear is problem that occurs at the point of contact between the materials. In material
selection, one should consider selecting material with a greater wear resistant.
Corrosion. Corrosion do occurs when a material reacts with moisture content. It is therefore
important to take note when making a selection and therefore select material that do not
easily corrodes.
Cost- cost is very important factor to be considered in in designing of materials. Costs in
Question 1.5:
A 3 meter long steel CHS (Circular Hollow Section) column, whose external diameter is 296
mm and has a wall thickness of 3 mm, is subjected to a tensile axial force F of 175kN.
Calculate the axial tensile stress due to the applied load?
Question 1.6:
Describe each of the following load types and detail two things that an engineer must
consider when determining the value/size of each load type
Permanent Loads (dead loads)
Dead loads are described as structural loads of constant magnitude over time. This loads
include the self-weight of structural members such as plasters, ceilings, beams, columns and
even floors. Dead loads also include loads of fixtures that are permanently attached to the
structure.
4. To determine the size of the dead loads, an engineer should ensure a repetition of member
sizes, and weights since a constant changes may be witnessed. The process is repeated till
the final member size is obtained.
Live loads
Live loads are temporarily or moveable loads attached to structure. This loads include loads
on a building created by the storage furniture and equipment, impact and also occupancy.
Wind loads
Wind loads is an example of environmental loads. They are pressure exerted on structures
by the flowing winds. Wind flows and directions do varies making it difficult to make
predictions on the exact pressures applied by wind on the existing structures.
Engineers therefore needs to know the relationship between the dynamic wind pressure
and wind velocity while designing of structures. This would enable them to known the
choice of structures to be built on different regions depending on the wind zone.
Question 1.7:
Limit state design is often referred to as a two-layered factor of safety approach. Explain
what this means, why it is done and how it is incorporated into the design and analysis
process?
Limit state design refers to design method used in the structural engineering.
It is done so that the capacity of load or the working load structure can be determined.
Limit state design is really important as it uses modern methods of design of structures
which also involves wide range of logical and technical considerations.
Question 1.8:
You are to design the size of a tensile cross bracing member. What must you know to be
able to determine the size of that member? You may provide an example to assist in
demonstrating your understanding.
To design the size of tensile across a bracing member, one must consider the corresponding
loadings on the structure on which the tension member forms part. Also the net area
required for the member.
5. Question 1.9:
A compressive member has a unique concern related to potential failure when compared to
tension members. Describe what this unique concern is? Then list four ways to increase the
compressive load capacity of a ‘long’ (or slender) column?
How to increase compressive load capacity
Reducing cement to water ratio
Altering the aggregates
Including admixture
By adjustment of cement type and quantity
Question 1.10:
A simplification of the structural process was detailed using the GLAD workflow. List and
describe each of the stages of the GLAD process for structural design
Question 1.11:
Describe two structural stability systems in detail including examples of their common
application in buildings?
Neutral equilibrium structure- this is a state by which the member remains in its initial
state while subjected to slight loading
Stable equilibrium structure. This occurs when a small perturbations do not cause large
movements as compared to that of a mechanisms.
Question 1.12:
Refer to the diagram of the 3D frame structure below. What would a suitable method be to
provide stability in the 3D frame from the load direction indicated at ‘A’? You may use
sketches to support your answer
Since the original frame’s support are hinged. The stability can be provided by the use of
braces which passes through the diagonals of the member as shown in the figure below.
Braces improves the stiffness of the member.
Task 2 – Reactions, Tributary Area And Beam Action
Question 2.1:
6. Find the reactions for the following simply supported beam.
Question 2.2:
Consider the concrete flat plate structure below. Respond to the following tasks:
Draw the tributary areas for each column.
What is the tributary area for C1, C5, C7 and C9?
What is the weight of the slab supported by column C9 (in kN)?
What is the weight of column C9 (in kN)?
What is the total weight of the structure?
Notes
Three story building
All dimensions are in meters.
Slab is 350mm thick
Floor to ceiling height is 3.4m – (the height of each column is 3.4m)
Columns are 400 x 400 mm
Unit weight is 25kN/m3
Question 2.3:
Consider the following beam which is experiencing a design load of 10kN. The beam is made
from a 290 x 35mm piece of timber with a Young’s Modulus of 9000MPa. The vertical
dimension of the timber beam is 290mm.
Equations:
What is the deflection of this beam?
a. Based on a deflection limit of span/300, is this acceptable? Justify your answer.
b. This deflection limit is not desirable as it causes visual distresses to the user of the
building and sometimes can lead to damage of parts of the building
c) If this rafter was not appropriate, what could the engineer do? Make three (3)
suggestions. For each suggestion, describe/detail how it would help with increasing the
beam’s performance. Then comment on which of the solutions would be the most viable and
justify your choice.
Question 3.1 (A)
Task 3 – Structural Systems
7. Question 3.1:
a. The diagrams below show the deformations of a simply supported concrete beam, a fixed
end concrete beam, a cantilever concrete beam and multi-span (or continuous) concrete
beam subject to point loads as shown.
Identify which parts of each beam are in tension and which parts are in compression. Label
these regions on the deflected shapes (on the right)
Draw on the beams (without deflection) where the steel reinforcement (for a normally
reinforced section) should be located for the loading given? The faint dotted line represents
the Neutral Axis of the beam.
Question 3.2:
Concrete can be designed to be under-reinforced or over-reinforced. What does this mean
and how does it influence the failure type?
Over-reinforced concrete do fails suddenly without any warning as a result of crushing the
concrete.
Under-reinforced concrete conditions occurs when the sections provides more warning
prior to the failure time.
Question 3.3:
Discuss the differences between a normal reinforced, pre-tensioned and post
tensioned concrete slabs. Consider the advantages, disadvantages, and construction
methodologies (6 marks)
Normal reinforced
Pre-tensioned
Post tensioned
Small sections constructed
8. Small sections are to be constructed
Size is not restricted
Whole concrete is useful in resisting external forces
Similar prestressed members are prepared
Products are changed according to structure
Question 3.4:
Why are the steel tendons in post-tensioned slabs usually draped so that they are close to
the top of the slab over supports and close to the bottom of the slab at the mid span?
Post tension slab is a combination of conventional slab reinforcement and additional
protruding high-strength steel tendons, which are consequently subjected to tension after
the concrete has set. This hybridizationov helps achieve the formation of a much thinner
slab with a longer span devoid of any column-free spaces
Question 3.5:
Discuss the structure presented below in relation to the system through which stability is
provided for both wind directions pictured. Provide detailed information for both the Cross
Wind and Longitudinal Wind. Please also comment on the ability for stability to be
“transferred” to other bays throughout the structure
9. Longitudinal wind
Question 3.6:
Inside any given structural system: a) list and describe three (3) potential causes of
vibration in the structure and b) list and describe three (3) potential solutions to vibration
within structures
Causes of vibration
- Structural resonance- this is a type of failure which occurs with smaller reciprocating
pumps or compressors.
- Dynamic forces generated by compressors
- Dynamic forces generated by pumps
- Dynamic forces generated by engines
To control vibration,
- The resonance need to be completely avoided
- By limiting vibrations of the structural member
Question 3.7: What Is Meant By Concrete Cover And Why Is It Important?
Concrete cover is referred to as the least distance between the surface of the embedded
reinforcement and the outer surface of the concrete.
Importance
Concrete cover do protects the steel from any harmful influences such as fire and aggressive
solutions.
Task 4 – Soil
Question 4.1:
a) A pad footing has to carry a design load of 450 kN and is founded in soil with a design
allowable bearing pressure of 200 kPa. What is the minimum required diameter of a
circular pad footing to resist this load? Show your workings.
First, area is to be calculated
10. b) During excavation to prepare the pad footing, unexpected material of lower strength is
encountered (100 kPa maximum). Describe two options that could be used to continue with
the preparation of a suitable footing. How would your proposed solution assist the
identified problem?
Question 4.2:
Illustrate (draw) three typical modes of failure mechanisms of retaining walls and describe
them in detail including potential causes of failure.
Overturning Failures
Causes of failure
-inadequate width of the base
-increase in the design loads as compared to that anticipated during the design.
-due to increase of the fill height with time
Sliding failures
11. Causes of failure
- The friction forces that exists between the base material and the rock
- Resistance that is provided by the cohesion in the rocks surfaces.
Bearing Failures
Causes of failures.
- Non-uniform pressure under the base of the walls.
- Soil stress under the base
- The vertical force acting on the soil.
Question 4.3:
Choose three (3) of the ground improvement techniques from the list below. Describe your
three chosen ground improvement techniques and give examples of their application.
12. Surcharge loading
Compaction
Soil mixing
Grouting
Soil reinforcement
Cement/lime stabilization
Surcharge loading- this type of loading results on the objects that add loadings to the
protective system. This loads are also referred to as vertical loads that is mostly used to
backfill the soil above the top of the walls.
Examples include live load ie, which results from highway and parking lot.
Compaction
Soil compaction basically occurs when the soil particles are pressed together therefore
reducing pores spaces present between them.
When the soil is compacted, there is a great reduction in for the rates of water infiltration
and drainage process.
Examples include; a typical example is compression of sediments in water bodies over a
period of time. This results to formation of sedimentary rocks.
Grouting
Grouting is the process of mixing sand, water and cement or chemical in order to fill the
gaps. This mixture is mostly used in filling gaps and repairs in the concrete crack. The
method is also used to seal and fill gaps purposely for waterproofing. Also for soil
stabilizations.
Question 4.4
Described and detail the composition of soil including detailing how different types of soils
are classified?
Clay soil- clay soil is composed of 60% clay minerals, 30% quartz and chert, 5% feldspar,
4% carbonates, 1% organic matter.
13. Sandy soil- sand soil is composed of 35% sand and less than 15% silt and clay. Sand is
basically small pieces of eroded rocks with some gritty texture.
Loamy soil- loamy soil is basically composed of almost equal amount of sand and silts with
little less clay.
Question 4.5
Described the two different types of foundation system (shallow and deep footings). What is
it that distinguishes between the two primary types of systems? Provide details of examples
of each? (3 marks)
Shallow foundation is a foundation which distributes loads from the buildings into layers of
the ground.
Deep footings- this is a type of foundation that transfers buildings loads to the earth farther
down from the surface then the shallow foundation does to a subsurface layer.
Shallow footings
Deep footings
Shallow foundation is considered cheaper
This types of foundation is more expensive than the shallow foundations
Depth is approximately 3 meters
Depth is greater than that of shallow foundations