This presentation discusses conceptual design considerations for earthquake-resistant structures. It emphasizes the importance of simplicity, symmetry, ductility, and a continuous load path in seismic design. Specific recommendations include using regular shapes without re-entrant corners in plan, avoiding soft or weak stories, maintaining uniform strength and stiffness, and designing horizontal members to fail before vertical members. The presentation also covers topics like structural materials, framing systems, the effects of non-structural elements, and the importance of flexibility versus stiffness. Overall, the conceptual design phase requires thorough consideration of form, shape, materials and structural behavior to avoid failure during earthquakes.
Progressive collapse is the result of a localized failure of one or two structural elements that lead to a steady progression of load transfer that exceeds the capacity of other surrounding elements, thus initiating the progression that leads to a total or partial collapse of the structure. The present study is to evaluate the behavior of G+8 reinforced concrete building subjected to potential collapse. The reinforced concrete structure is analyzed by Pushover Analysis using ETABS Software. It shows the maximum storey displacement and a maximum storey drift values of the components are studied. And the potential of the progressive collapse is determined.
Progressive collapse is the result of a localized failure of one or two structural elements that lead to a steady progression of load transfer that exceeds the capacity of other surrounding elements, thus initiating the progression that leads to a total or partial collapse of the structure. The present study is to evaluate the behavior of G+8 reinforced concrete building subjected to potential collapse. The reinforced concrete structure is analyzed by Pushover Analysis using ETABS Software. It shows the maximum storey displacement and a maximum storey drift values of the components are studied. And the potential of the progressive collapse is determined.
A report format presentation of earthquake-resistance construction techniques, stressing upon the relevance of such techniques in the architecture industry.
This presentation elucidates the seismic behaviour of beam-column joint and some methods to improve the resistance of beam-column joints to seismic loads to avoid disasters.
Dhruvin Goyani
M.Tech Structural
This PPT is For All the Civil Engineering Students and Specially for M.tech Students Who Trying To Learn Something New on Earthquake and its Resisting Methods and also For Seismic Analysis
Study of shear walls in multistoried buildings with different thickness and r...eSAT Journals
Abstract This paper investigates the effect of different thickness and corresponding reinforcement percentages required for shear walls on multi-storied buildings. Building models with shear walls are developed using ETABS. The location of the shear walls are kept same and a comparative study is done for different thickness of the shear wall for different height of the building (5 storied, 10 storied and 15 storied). In each of the cases corresponding reinforcement percentages required are found out. It is observed that for a constant thickness of shear wall, reinforcement percentage increases with increase of both seismicity and number of stories. It is also observed that for all zones, the reinforcement percentage increases if the shear wall thickness increases for a certain range of thickness and then decreases for a certain range of thickness. Thus the results indicate that increase of shear wall thickness is not always effective for earthquake resistant design. Keywords: Shear Wall, ETABS, earthquake resistant design.
A report format presentation of earthquake-resistance construction techniques, stressing upon the relevance of such techniques in the architecture industry.
This presentation elucidates the seismic behaviour of beam-column joint and some methods to improve the resistance of beam-column joints to seismic loads to avoid disasters.
Dhruvin Goyani
M.Tech Structural
This PPT is For All the Civil Engineering Students and Specially for M.tech Students Who Trying To Learn Something New on Earthquake and its Resisting Methods and also For Seismic Analysis
Study of shear walls in multistoried buildings with different thickness and r...eSAT Journals
Abstract This paper investigates the effect of different thickness and corresponding reinforcement percentages required for shear walls on multi-storied buildings. Building models with shear walls are developed using ETABS. The location of the shear walls are kept same and a comparative study is done for different thickness of the shear wall for different height of the building (5 storied, 10 storied and 15 storied). In each of the cases corresponding reinforcement percentages required are found out. It is observed that for a constant thickness of shear wall, reinforcement percentage increases with increase of both seismicity and number of stories. It is also observed that for all zones, the reinforcement percentage increases if the shear wall thickness increases for a certain range of thickness and then decreases for a certain range of thickness. Thus the results indicate that increase of shear wall thickness is not always effective for earthquake resistant design. Keywords: Shear Wall, ETABS, earthquake resistant design.
Journal of Construction Engineering Technology & Management vol 6 issue 3STM Journals
Journal of Construction Engineering, Technology and Management (JoCETM) is a Journal focused towards the rapid publication of fundamental research papers on all areas of Construction Engineering, Technology and Construction Management.
Focus and Scope Covers
Planning and Management of the Construction of Structures
Design of Temporary Structures
Quality Assurance and Quality Control
Building and Site Layout Surveys
On Site Material Testing,
Safety Engineering, Materials Procurement, Budgeting & Cost Engineering
Concrete Mix Design
Dual Systems Design Shear wall-Frame InterAction تصميم الجملة القصية الثنائية...Dr.Youssef Hammida
Dual systems These systems are the result of combining the two latter systems to resist the lateral load, in these systems the shape of the deformations will differ from those in frames and walls systems, where e... more abstract
Structural Engineering
There are some circumstances, however, where the rigid diaphragm assumption may not be appropriate: floors with numerous openings, roof diaphragms of metal decking without concrete fill or of plywood sheathing, etc. Long, narrow diaphragms may be considered rigid in one direction but not in the other. For structures with multiple wings, such as L- or C-shaped buildings where the ends of the wings can drift independently of each other, the rigid diaphragm analysis may not be appropriate since it would lock the ends of the wings together, constraining them to move in unison
Seismic analysis and design
Special shear walls + ordinary shear walls ACI - 318 - جدران القص الخاصة - P...Dr.Youssef Hammida
Specifications of Special
shear walls
• 1- to form a plastic hinge and wall work in the plastic area
distracting section of the quake, where increasing energy transfer and nonlinear distortions
With firmness despite rising resistance section loads base shear forces
Detailed plastically shaped at the bottom of the wall up the foundation base point
Where the forces of bending moment and shear baseband is greatest
• 2 - have a long high hinge plastically area along the height of the wall
And almost equal to the rise in the wall / 6, H / 6 or along the plan length L
• 3 - the region where the plastic hinge cracked consider (cracked section) and the reduction of inertia (Ig) = (0.35 - 0.5) according to the local code
But after the hinge ductile shear wall treats ordinary wall
area (un cracked section) = (0.7 - 0.8)
• 4 - neglecting the resistance of concrete to resist shear forces
and reinforcing longitudinal and horizontal
In the area and the plastic hinge along only
Desain dinding geser beton bertulang menggunakan software ETABSAfret Nobel
Desain dinding geser beton bertulang menggunakan software ETABS adalah langkah-langkah dalam mendesain dinding geser / shear wall menggunakan software etabs.
A technical approach to designing earthquake resistant buildings. Contains a brief overview of why a structure fails, building foundation problems and what are the possible solutions
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
Conceptual design
1. PRESENTATION ON
CONCEPTUAL DESIGN
Made By:
NAGMAALAM
M.TECH.-EARTHQUAKE ENGINEERING
3RD SEMESTER, 2016-17
DEPARTMENT OF CIVIL ENGINEERING
JAMIA MILLIA ISLAMIA
SUBJECT: EARTHQUAKE RESISTANT
DESIGNOF STRUCTURES
(DR.AKIL AHMAD)
2. CONCEPTUAL DESIGN
While conceiving a new construction project, an architect should give
thorough thought to the form, shape, and material of the structure, as
well as the functional and cost requirements, to avoid a critical failure
during earthquake.
Often, architects conceive wonderful and imaginative forms and
shapes to create an aesthetic and functionally efficient structure. But
the architect should interact with the structural engineer to conceive
most appropriate and seismically safe structure.
The basic factors contributing to proper seismic behaviour of a
building are simplicity, symmetry, ductility, and transfer of the lateral
loads to the ground without excessive rotation.
The behaviour of a structure during an earthquake depends largely on
the form of the superstructure and on how the earthquake forces are
carried to ground. For this reason the overall form, regular
configuration, flow of loads, and the framing system of the building
may be serious concern if not taken care of the first stage of planning.
4. OVERALL FORM
While planning a structure, the guiding principles should be
kept in mind are as follows-
Be simple and symmetric.
Not be too elongated in plan or elevation i.e, size should
be moderate.
Have uniform and continuous distribution of strength,
mass and stiffness.
Have horizontal members which form hinges before
vertical members.
Have sufficient ductility.
Have stiffness related to the sub-soil properties.
5. SIMPLICITY AND SYMMETRY
A square and circular shape will have the greatest chance to survive
due to following reasons –
a) The ability to understand the overall EQ behaviour of a structure.
b) The ability to understand the structural details.
c) Uniformity in plan improves dynamic performance of a structure
during an EQ by suppressing torsional response.
Buildings with regular plan and elevation and without re-entrant
corners display good seismic behaviour.
Buildings with re-entrant corners, such as U, V, T and + shapes in
plan, may sustain significant damage during EQ and should be
avoided.
H-shapes, although symmetrical, should not be encouraged either.
The geometrical plan of typical buildings are shown in next slide.
7. The probable reason for the damage is the lack of proper detailing at the corners, which is
complex. To check the bad effects of these interior corners in plan, the building can be
broken into parts using a separation joint at the junction. There must be enough clearance at
the separation joints so that the adjoining portions do not pound each other. Some cases of
elongated, L-shaped and H-shaped buildings are shown below.
BROKEN LAYOUT CONCEPT
8. ELONGATED SHAPES
If different parts of the building is shaken out, incalculable stresses
are being imposed which increases with size.
Buildings which are too long in plan may be subjected to different
EQ movements simultaneously at the two ends, which may separate
the building into no. of square buildings.
Buildings with too large plan area (warehouses) may subjected to
excessive seismic forces that will have to be carried out by the
columns and walls.
In buildings with large height-to-base ratio (λ=4) horizontal
movement of floors during ground shaking is large.
More slender a building, worse the overturning effects of the EQ.
10. STIFFNESS AND STRENGTH
Strength is the property of an element to resist force. Stiffness
is the property of an element to resist displacement.
On the basis of stiffness, the structure may be classified as
brittle and ductile.
A brittle structure having greater stiffness proves to be less
durable during EQ, while a ductile structure performs well in
EQ.
Uniformity of strength and stiffness in elevation helps to
avoid formation of soft and weak storey.
A sudden change of lateral stiffness of a building is not
acceptable due to following reasons –
a) Even with most sophisticated and expensive computerized
analysis, the EQ stress can not be determined adequately.
b) The structural detailing poses practical problems.
11. • Buildings with vertical setback cause a sudden jump of
EQ forces at the level of discontinuity
12. • Buildings that have fewer columns or walls in a particular
storey or that have unusually tall storey are prone to damage
or collapse.
13. • One of the most common form of discontinuity occurs in
vertical elements when shear walls that are present in upper
floors are discontinued in the lower floors which results in
frequent formation of soft storey that concentrates damages.
14. • The unequal height of columns causes twisting and damage
to the short columns of the building. It is because shear force is
concentrated in relatively stiff short columns which fails before
the long columns.
15. • Buildings with columns that hang or float on beams at an
intermediate storey have discontinuities in load transfer path.
16. HORIZONTAL AND VERTICAL
MEMBERS
In a framed structure, horizontal members i.e., beams and slabs should
fail prior to the vertical members i.e., columns.
Beams and slabs generally do not fall down even after sever damage
whereas columns collapse rapidly under the vertical loading.
Continuous beams on weak columns are not appreciated in EQ prone
region and weak-beam--strong-column arrangement should be the choice.
Following are the reasons for having weak-beam—strong-column
a) Failure of column means collapse of the entire building.
b) In a weak-column structure, plastic deformation is concentrated in a
particular storey and a relatively large ductility factor is required.
c) in both shear and flexural failure of columns, degradation are greater than
those in yielding of beams.
18. TWISTING OF BUILDINGS
Twist in buildings cause different portions at the same
floor level to move horizontally by different level.
Irregularities in mass, stiffness and strength in a building
can result significant torsional response.
Torsion arises from eccentricity in the building layout—
when the centre of mass of the building does not
coincide with its centre of rigidity.
The recommended plan configuration of buildings to
avoid torsional moments due to distribution of mass and
stiffness of elements shown in next slide.
24. DUCTILITY
Ductility is the capacity of building materials, systems, structures, or members to
undergo large inelastic deformations without significant loss of strength of
stiffness.
Ductility refers to the ratio of the displacement just prior to ultimate displacement
or collapse, to the displacement at first damage or yield.
The vibration produced by EQ, as well as the accompanying deflection, is reduced
by the energy that is absorbed by the large inelastic deflections of a ductile
structure.
Buildings constructed of ductile materials, such as steel and adequately reinforced
concrete, wood (having reserve capacity) tend to withstand EQ much better than
those constructed of brittle materials such as unreinforced masonry.
Way to achieve ductility—
In RCC members, the amount and location of steel should be such that the failure
of the member occurs by steel reaching its strength in tension before concrete
reaches its strength in compression. This is known as ductile failure.
The failure of a beam causes localized effects. The failure of a column can affect
the stability of the whole building. Therefore, it is better to make beams ductile
rather than columns. Such method is known as strong-column—weak-beam
design method.
25. • For the entire structure to be ductile, the following requirements must be
met :
a) Any mode failure should involve the maximum possible redundancy.
b) Brittle-type failure modes, such as overturning, should be adequately
safeguarded so that ductile failure occurs first.
Types of brittle failure—
26. FLEXIBLE BUILDING
The ground shaking during an EQ contains a group of many sinusoidal
waves of different frequencies having periods in the range of 0.03 to 33 s.
The building oscillates back and forth horizontally and after some time
comes back to the original position.
The time taken (in seconds) for one complete back and forth motion is
called the fundamental natural period , T, of the building.
The higher the flexibility , the greater the value of T.
A flexible structure with moment resisting frames (beam and column) is
built so that non-structural elements such as partitions and infill walls are
isolated from the frame movements. This is necessary because a flexible
structure tends to exhibit large lateral deflections, which induce damage in
non structural members.
For flexible structure, materials like masonry are not suitable and steel
work is the usual choice.
27. In a stiff (rigid) building, every part moves by the same amount as the ground.
For greater stiffness, diagonal braces or RCC shear wall panels may be incorporated in
steel frames, Concrete can be readily used to achieve almost any degree of stiffness.
The differences between Flexible structure and Stiff structure are shown below.
28. FRAMING SYSTEM
The ability of a multi-storey building to resist the lateral forces
depends on the rigidity of the connections between the beams and the
columns.
When the connections are fully rigid, the structure as a whole is
capable of resisting the lateral forces.
If the strength and stiffness of a frame are not adequate, the frame may
be strengthened by incorporating load-bearing walls, shear walls,
and/or bracings.
Shear wall and bracings are also capable of preventing the failure of
non-structural members by reducing drift.
Shear walls which are made of RCC, steel, composite, and masonry
are situated in advantageous positions in a building that can
effectively resist lateral loads.
For buildings taller than about forty stores, the effect of lateral forces
becomes increasingly intense, and tube systems become economical.
30. FRAMED TUBE
• Closely spaced columns are tied at each floor level by deep spandrel beams,
thereby creating the effect of a hollow tube, perforated by openings for windows.
• This system represents a logical evolution of the conventional framed structure,
possessing the necessary lateral stiffness with excellent torsional qualities, while
retaining the flexibility of planning.
31. TRUSSED TUBE
• It is an advancement over the framed-tube system.
• The diagonal members, along with girders and columns,
form a truss system that imparts a great deal of stiffness to
the building.
32. TUBE-IN-TUBE
• It consists of an exterior tube that resists the bending
moment due to lateral forces and an interior slender tube,
which resists the shear produced by the lateral forces.
33. BUNDLED -TUBE
• It is made up of a number of tubes separated by shear
walls.
• The tubes rise to various heights and each tube is
designed independently.
34. EFFECT OF NON-STRUCTURES
Non structural elements such as in-fill walls, partition walls, etc.
Interfere with the free deformation of the structure and thus become
structurally very responsive in EQ.
If the material used in construction is flexible, the non-structures
will not affect the structure significantly.
If the materials used are brittle, then it affect the overall behaviour of
structure in the following ways:--
a) The natural period of vibration of the structure may be reduced and
may cause a change in the intake of seismic streeses of the structure.
b) the lateral stiffness of teh structure may redistribute, changing yhe
stress distribution.
c) The structure may suffer pre-mature failure, usually in shear or by
pounding.
d) Non-structures may suffer excessive damage due to shear forces or
pounding.
35. CHOICE OF CONSTRUCTION
MATERIALS
Some of common construction materials in use are clay, bricks,
stones, timber, cement-concrete, and steel.
Brick or stone masonry is strong in compression but weak in
tension, and the same is true for cement-concrete.
Reinforced masonry is relatively superior with regard to the
strength-to-weight ratio, degradation, and deformability, and it is also
less expansive.
Steel, though expansive, is the ultimate choice to make a building
ductile.
RCC structures are inferior to steel structures with respect to
strength-to-weight ratio, degradation, and deformability.
Prestreesed concrete structures, the introduction of prestressing
adversely affects the deformability and hence the seismic
characteristics of the building.
37. For the purpose of EQ resistance, construction materials should have the
following desirable properties :
a) High ductility : High plastic deformation capacity can enhance the load
carrying capacity of the members.
b) High strength-to-weight ratio: Since the inertial force is a function of
mass of the structure, it is advantageous to use light and strong materials
or structural systems.
c) Orthotropy and Homogeneity: The basic physical model in seismology
is that of a perfectly elastic medium in which the infinitesimal strain
approximation of a elastic theory is adopted. Anisotropy imperfections in
elasticity and inhomogeneities modify the response predicted by simpler
theories and thus are undesirable.
d) Ease in making full strength connections: Since both ductile and
brittle members can result from a combination of,e.g., brittle concrete and
ductile steel, performance of structural elements cannot be evaluated by
materials alone. Further, the structural continuity at connections is of
great importance in evaluating the behaviour of an entire system.
e) Cost: A building plan is often discarded because of high cost despite its
superior physical quality. The cost of the overall structure should be
reasonable.