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
3. 3
Walls should be proportioned to satisfy strength and drift limit
requirements of ASCE 7, unless an alternative approach is approved.
According to ASCE 7, walls are designed for load combinations in which
seismic forces, E, are determined using a force reduction factor, R. The
value of R depends on whether the wall is part of a Dual System (R = 7),
a Building Frame System (R = 6), or a Bearing Wall System (R = 5).
To qualify as a Dual System, the special structural walls must be
combined with special moment frames capable of resisting at least 25 %
of prescribed seismic forces.
If it does not qualify as a Dual System, then it can qualify as a Building
Frame System if it has an essentially complete space frame providing
support for vertical loads, with structural walls providing seismic force-
resistance.
If there is not a complete space frame providing support for vertical
loads, the system must be designed as a Bearing Wall System.
5. 5
-Shear walls in buildings must be symmetrically
located in plan to reduce ill-effects of twist in buildings
They could be placed symmetrically along
one or both directions in plan.
-Shear walls are more
effective when located along exterior perimeter of the
building – such a layout increases resistance of the
building to twisting.
7. 7
2-اﻟﻨﮫﺎﻳﺎت ﻓﻲ اﻋﻤﺪة واﺿﺎﻓﺔ اﻟﻤﻄﺎوﻋﺔ ﻟﺰﻳﺎدة اﻹﺟﺮاءت اﺗﺨﺎذ وﻳﺠﺐ
ﻓﻲ اﻟﻀﺎﻏﻄﺔ اﻟﺸﺎدة اﻟﻘﻮى ﻟﻤﻘﺎوﻣﺔﻓﻲ ﺣﺘﻰ اﻟﻤﻘﺎوﻣﺔ اﺳﺘﻤﺮار واﻣﻜﺎﻧﯿﺔ اﻟﻨﮫﺎﻳﺎت
اﻟﻠﺪو ﻣﺮﺣﻠﺔﻧﺔ
3-اﻟﺘﻮازﻧﯿﺔ اﻟﻨﺴﺒﺔ ﻋﻠﻰ اﻟﻤﺤﺎﻓﻈﺔ ﻳﺠﺐ اﻟﻤﻄﺎوﻋﺔ ﻋﻠﻰ ﻟﻠﻤﺤﺎﻓﻈﺔ ھﺬا وﻋﻠﻰ
اﻟﻀﻌﻂ ﻓﻲ
ﺑﯿﻦPU & P0----0,50P0-pu= 0.35ﻓﻲ اﻟﺘﺴﻠﯿﺢ ﺗﺮﻛﯿﺰ ﻳﺠﺐ ذﻟﻚ ﻋﻦ زادت واذا
ﺿﺎﻏﻄﺔ ﺷﺎدة ﻗﻮى اﺳﺎس ﻋﻠﻰ اﻟﺠﺪار ﻧﮫﺎﻳﺎت
walls Plasticityshear
The reason is the low plasticity walls loaded with high axial load and up to
zero and plasticity decreases with increasing vertical load due to the
increase in the curvature of the yield, which reduces plasticit
1 - with increased axial loads applied to the shear walls and virtually no
exposure at the walls, at least 50% - plasticity shear strength pressure up
to the Great axial force allowed applied to the wall.
2 - in the boycotted shear walls with regular reinforcement less plasticity
with an increase rate of reinforcement.
3 - remain, in excerpts of shear walls with hidden columns plasticity
stable with the increase in the proportion of armament in these columns.
4 - plasticity less clearly with the increase in the length of the walls so it
prefers to use multiple short walls, snipping at each of the main directions
of the building where it can.
1. 5- it recommended a review of the force applied to the permitted
2. shear walls that contribute to resist loads, seismic in the Syrian Arab
code and do not let axial strongly make compliant few wlls
unacceptably.
6 - ً◌ also recommended must take factors that affect the compliance of
rotation and move to shear walls.
12. 12
Modeling Beam and Wall Properties Elastic analysis is sufficient to
determine a theoretical degree of coupling for a coupled wall structure
and thus the distribution of internal forces in the walls and beams. Local
inelasticities at the beam-wall interfaces, redistribution of forces between
coupling beams and from the tension wall to the compression wall and
strain hardening effects all contribute to reducing the theoretical degrees
of coupling.
Reduced section properties, accounting for cracking and loss of stiffness
due to cycling can be used to determine a more appropriate value for the
theoretical degree of coupling. Table 2 shows the reduced stiffness values
suggested by the current ACI, CSA and NZS standards. ACI 318-99
recommends the use
16. 16
lingkShear walls buc
Figure 6: Details of the compression failure in the walls of the
Building, including buckling of the longitudinal rebar
Figure 3: Buckled longitudinal rebar in structural wall of building
37. 37
Figure :1 Schematic elevations and plans for structural systems
in reinforced concrete: a) moment-resisting frame; b) bearing-
wall system; c) frame/shear-wall hybrid system.
Bearing Wall System
Figure :3 Bearing Wall System/ shear wall system
38. 38
Figure :4 Frame/Shear Wall Hybrid System
A frame/shear-wall hybrid system utilizes a complete 3-D space frame to
support gravity loads and shear walls to resist lateral loads (see Figure
1c).
39. 39
Use of a dual system has the advantage of providing the structure with
an
independent vertical load carrying system capable of resisting 25 percent
of the
design base shear while at the same time the primary system, either
shear wall orbraced frame, carries its proportional share of the design
base shear. For this
configuration, the code permits use of a larger R value for the primary
system hanwould be permitted without the 25 percent frame system
40. 40
.
The G1 reinforcement consists of the clearly defined
reinforcement of the three members that comprise the
compound element, the two orthogonal columns and the shear
wall’s main body.
47. 47
1• shear walls that do not requir to form elastic hinges ,
where the entire resist base shear force in the field of flexibility plasticity
zone
2• - factor (R) in excess of the resistance gives her on the basis of
elasticity And plasticity in the flexible deformation field where the entire
resist shear strength
Baseband without detailed born constitutes or dissipating energy factor
(R) range (4 - 4.5)
3• - Due to the field of resistance in the elastic plastic regions is one of
the sulfides Section property of others cracked uncracked section where
the cracks are limited to the elements of structural and can be processed
without the need to evacuate the population .
to reduce the amount of inertia (Ig) and range from
(0.7 - 0.8) for Walls
4• - resist shear forces by concrete section and the longitudinal,
horizontal reinforcement
5• must be secured plasticity plasticity adequate reinforcement ratios
Minimal equilibrium to the presence of columns endings on the outskirts
of the walls
6• calculated as regular columns and walls collapse achieve elastic
counted Rather fragile and sudden curves, according to curved
interaction curve where the horizontal and transverse reinforcement to
resist shear forces horizontal and vertical resist vertical loads.
52. 52
walls bucklingShear
Figure 6: Details of the compression failure in the walls of the
Building, including buckling of the longitudinal rebar
53. 53
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
54. 54
calculated resistance after the plastic hinge area
5 - Provide plasticity. Elacticity of sufficient reinforcing ratios
Minimal and equilibrium to the presence of special columns in
the endings the edges of the walls (Boundary condition) and
achieve the requirements of the code as well as the
resistance and dimensions
6 - calculated walls and columns and to achieve flexible
collapse calculated rather fragile and sudden, according to a
curved interaction
7- preferred calculate (Buckling) in columns endings special
presence compression tension on the edge of the wall