This publication provides a concise compilation of selected rules in the Eurocode 8 Part 1 & 3, together with relevant Cyprus National Annex, that relate to the seismic design of common forms of concrete building structure in the South Europe. Rules from EN 1998-3 for global analysis, type of analysis and verification checks are presented. Detail design check rules for concrete beam, column and shear wall, from EN 1998-3 are also presented. This guide covers the assessment of orthodox members in concrete frames. It does not cover design rules for steel frames. Certain practical limitations are given to the scope. Due to time constraints and knowledge, I may not be able to address the whole issues. Please send me your suggestions for improvement. Anyone interested to share his/her knowledge or willing to contribute either totally a new section about Eurocode 8-3 or within this section is encouraged.

1. Design notes for seismic assessment
of existing structure in accordance
to EUROCODE 8-PART 3
VALENTINOS NEOPHYTOU BEng (Hons), MSc
REVISION 1: January, 2014

2. ABOUT THIS DOCUMENT
This publication provides a concise compilation of selected rules in the Eurocode 8 Part 1 &
3, together with relevant Cyprus National Annex, that relate to the seismic design of
common forms of concrete building structure in the South Europe. Rules from EN 1998-3
for global analysis, type of analysis and verification checks are presented. Detail design
check rules for concrete beam, column and shear wall, from EN 1998-3 are also presented.
This guide covers the assessment of orthodox members in concrete frames. It does not cover
design rules for steel frames. Certain practical limitations are given to the scope.
Due to time constraints and knowledge, I may not be able to address the whole issues.
Please send me your suggestions for improvement. Anyone interested to share his/her
knowledge or willing to contribute either totally a new section about Eurocode 8-3 or within
this section is encouraged.
For further details:
My LinkedIn Profile:
http://www.linkedin.com/profile/view?id=125833097&trk=hb_tab_pro_top
Email: valentinos_n@hotmail.com
Slideshare Account: http://www.slideshare.net/ValentinosNeophytou

3. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Limit state
Mean return
period in years
TR = 2475
(Vary Rare
Earthquake)
Near
Collapse (NC)
TR = 475
(Rare
Earthquake)
TR = 225
(Frequent
Earthquake)
Significant
Damage (SD)
TR = 2475
(Vary Rare
Earthquake)
FUNDAMENTAL REQUIREMENT – LIMIT STATE (LS)
(EN1998-3,cl.2.1)
Combination
Probability of
of action and
exceedance in
Description
performance
50 years
levels
The structure is heavily damaged, with low
2%
2475/NCS
residual lateral strength and stiffness,
although vertical elements are still capable
of sustaining vertical loads. Most non-
10%
475/NC
structural components have collapsed. Large
permanent drifts are present. The structure
is near collapse and would probably not
20%
225/NC
survive another earthquake, even of
moderate intensity.
The structure is significantly damaged, with
2%
2475/SD
some residual lateral strength and stiffness,
and vertical elements are capable of
sustaining vertical loads. Non-structural
TR = 475
(Rare
Earthquake)
10%
Valentinos Neophytou BEng (Hons), MSc
475/SD
components are damaged, although
partitions and infills have not failed out-of-
Page 3 of 61

4. Design notes for Seismic Assessment to Eurocode 8 - Part 3
plane. Moderate permanent drifts are
TR = 225
(Frequent
Earthquake)
present. The structure can sustain after20%
225/SD
shocks of moderate intensity. The structure
is likely to be uneconomic to repair.
TR = 2475
(Vary Rare
Earthquake)
The structure is only lightly damaged, with
2%
2475/DL
structural elements prevented from
significant yielding and retaining their
strength and stiffness properties. Non-
Damage
Limitation
(DL)
TR = 475
(Rare
Earthquake)
10%
475/DL
structural components, such as partitions
and infills, may show distributed cracking,
but the damage could be economically
TR = 225
(Frequent
Earthquake)
repaired. Permanent drifts are negligible.
20%
225/DL
The structure does not need any repair
measures.
Note 1: TR values above same as for new buildings. National authorities may select lower values, and require compliance with only two limitstates.
Note 2: The acceptable performance level for ordinary buildings of importance should be “Significant Damage” which is roughly equivalent with
the “No Collapse” in EN1998-1.
Note 3: The National Authorities decide whether all three Limit States shall be checked, or two of them, or just one of them.
Note 4: The performance levels for which the three Limit States should be met are chosen either nationally through the National Annex to this
part of Eurocode 8, or by the owner if the country leaves the choice open.
Valentinos Neophytou BEng (Hons), MSc
Page 4 of 61

5. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Performance Levels and Limit States
Valentinos Neophytou BEng (Hons), MSc
Page 5 of 61

6. Design notes for Seismic Assessment to Eurocode 8 - Part 3
PERFORMANCE REQUIREMENTS AND COMPLIANCE CRITERIA
(EN1998-1-1,cl.2.1)
Return-period ground motion in TR years
Value of the exponent, k
Importance factor based on
reference seismic action
k=3
−1/𝑘
𝛾𝐼 =
𝑇 𝐿𝑅
𝑇𝐿
𝑃𝐿
𝑃 𝐿𝑅
−1/𝑘
𝛾𝐼 =
Importance factor based on
reference probability of
exceeding the seismic action
Mean return period
EN19981-1,cl.2.1(4)
𝑇𝑅 = −
EN19981-1,cl.2.1(4)
𝑇𝐿
𝑙𝑛 1 − 𝑃 𝑅
EN19981-1,cl.2.1(4)
EN1998-1-1,cl.2.1(1)
Typical values and relationships of reference probabilities of exceedance and corresponding
return periods for a specific site.
Probability of exceedance PR
Time span TL
Mean return period TR
20%
10 years
45 years
10%
10 years
95 years
20%
50 years
224 years
10%
50 years
475 years
5%
50 years
975 years
10%
100 years
949 years
5%
100 years
1950 years
Valentinos Neophytou BEng (Hons), MSc
Page 6 of 61

7. Design notes for Seismic Assessment to Eurocode 8 - Part 3
REDUCED DESIGN LIFE OF THE BUILDING
(EN1998-1,cl.2.1)
By reducing the remaining
lifetime of the building is reduced
the design ground acceleration
Valentinos Neophytou BEng (Hons), MSc
Page 7 of 61

8. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Peak ground acceleration attenuation relationships for the European area proposed by
Ambraseys et al. (1996)
Valentinos Neophytou BEng (Hons), MSc
Page 8 of 61

9. Design notes for Seismic Assessment to Eurocode 8 - Part 3
SEISMIC ZONATION MAP
(CYS NA EN1998-1)
The seismic building code of Cyprus includes seismic zonation based on ground acceleration values
with 10% probability of exceedance in 50 years, i.e., 475years mean return period. Five zones (1-5)
are defined with PGA ranging from 0.075g to 0.15g. In a recent revision of the code (2004), three
seismic zones are defined.
Valentinos Neophytou BEng (Hons), MSc
Page 9 of 61

10. Design notes for Seismic Assessment to Eurocode 8 - Part 3
REQUIRED INPUT DATA – CHECK LIST
(EN1998-3,cl3.1, 3.2 & Annex A.2)
Check
Description of identification
Parameter
Results/Comment
tick
√
I
II
Identification of “new” importance class
III
IV
Does the building design using any the
Prior 1994
previous seismic code?
After 1994
Construction date of building
Date
Column
Present of peeling cracks
If YES, provide
Beam
Wall
Valentinos Neophytou BEng (Hons), MSc
Page 10 of 61

11. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Slab
Sign of steel
Physical condition of reinforced concrete
deterioration
Column
Beam
elements and presence of any degradation,
Wall
due to carbonation, steel corrosion, etc.
Slab
Vertical at mid-span
Beams
Diagonal at ends
Are there any significant cracks on
structural members
Diagonal at ends (joints)
Columns
Mid-span
Diagonal at ends (joints)
Walls
Mid-span
Measure crack width of basement walls
Settlement of structure due to weak
foundation
Valentinos Neophytou BEng (Hons), MSc
If YES provide the crack width
If YES provide which side of the building have been settled
Page 11 of 61

12. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Are there any presents of cracks of infill
walls at the connection points
Is there any present of strengthening to the
structural members
If YES provide where
If YES provide where
Regular in plan
Identification of the structural regularity
Regular in elevation
Continuity of load paths between lateral
resisting elements.
Column supported on beam
Missing any structural member
Frame system
Dual system
Frame-equivalent dual system
Type of structural system
Wall equivalent dual system
Torsionally flexible system
Inverted pendulum system
Identification of the lateral resisting system
Valentinos Neophytou BEng (Hons), MSc
Moment frame/wall system in X direction
Page 12 of 61

13. Design notes for Seismic Assessment to Eurocode 8 - Part 3
in both directions.
Moment frame/wall system in Y direction
Distribution of infill walls
Regular in plan
Identification of the type of building
Raft foundation
foundation
Pad foundation
Pile foundation
Strip foundation
Is there any building attached?
Attached YES/NO
If YES measure the gap between them
Change of existing usage.
Variable
If YES re-assess the variable load
Re-assessment if imposed
Installation of any further load (i.e.
actions/permanent load.
Permanent
antenna, board)
If YES re-assess the permanent load
Solid slab
Thickness/dimensions
Flat slab
Thickness/dimensions
Type of slab
Valentinos Neophytou BEng (Hons), MSc
Page 13 of 61

14. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Waffle slab
Thickness/dimensions
Ribbed slab
Thickness/dimensions
Beams
Depth and width of concrete elements
Columns
Walls
Width of flanges in T-beams
Possible eccentricities between beams and
columns axes at joints.
Is there any asymmetric setbacks at all
storeys
Is there any effects of short columns
Is there any structural member run with
interruption from their foundation to top?
If exist, measure the width
If eccentricities exist check if YES provide the distance (check
if e ≤ bc / 4).
If YES provide the distance from the previous storey
YES / NO
YES / NO
Is the ground floor is soft storey (pilotis)
YES / NO
Identification of the ground conditions.
A
Valentinos Neophytou BEng (Hons), MSc
Page 14 of 61

15. Design notes for Seismic Assessment to Eurocode 8 - Part 3
B
C
D
E
Column
Beam
Amount of longitudinal steel in beams,
Slab
columns and walls.
Wall
Valentinos Neophytou BEng (Hons), MSc
Page 15 of 61

16. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Column
Beam
Amount and detailing of confining steel in
critical regions and in beam-column joints.
Slab
Valentinos Neophytou BEng (Hons), MSc
Page 16 of 61

17. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Wall
Amount of steel reinforcement in floor
slabs contributing to the negative resisting
bending moment of T-beams.
Column
Seating and support conditions of
Beam
horizontal elements.
Slab
Valentinos Neophytou BEng (Hons), MSc
Page 17 of 61

18. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Wall
Column
Beam
Depth of concrete cover.
Slab
Wall
Valentinos Neophytou BEng (Hons), MSc
Page 18 of 61

19. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Column
Beam
Lap-splices for longitudinal reinforcement.
Slab
Wall
Concrete strength.
Column
Beam
Valentinos Neophytou BEng (Hons), MSc
Page 19 of 61

20. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Slab
Wall
Column
Beam
Steel yield strength, ultimate strength and
ultimate strain.
Slab
Wall
Valentinos Neophytou BEng (Hons), MSc
Page 20 of 61

21. Design notes for Seismic Assessment to Eurocode 8 - Part 3
DEFINITION OF KNOWLEDGE LEVEL
(EN1998-3,cl.3.3.2)
Knowledge level KL2
The overall structural geometry and
The overall structural geometry and
member sizes are known either:
member sizes are known either:
member sizes are known either:
(a) from survey or
(a) from an extended survey or
(a) from a comprehensive survey or
(b) from original outline
(b) from outline construction
(b) from the complete set of outline
construction drawings used for both
drawings used for both the original
construction drawings used for both the
the original construction and any
construction and any subsequent
original construction and any subsequent
subsequent modifications.
Geometry
Knowledge level KL1
The overall structural geometry and
Factors
modifications.
modifications.
In case (b), a sufficient sample of
In case (b), a sufficient sample of
In case (b), a sufficient sample of both
dimensions of both overall geometry dimensions of both overall geometry
Knowledge level KL3
overall geometry and member sizes should
and member sizes should be
and member sizes should be checked be checked on site; if there are significant
checked on site; if there are
on site; if there are significant
discrepancies from the outline
significant discrepancies from the
discrepancies from the outline
construction drawings, a fuller
outline construction drawings, a
construction drawings, a fuller
dimensional survey is required.
fuller dimensional survey should be
dimensional survey is required.
performed.
The structural details are not known
The structural details are known either
from detailed construction drawings
either from extended in-situ
from comprehensive in-situ inspection or
and may be assumed based on
inspection or from incomplete
from a complete set of detailed
simulated design in accordance with
Details
The structural details are known
detailed construction drawings.
construction drawings.
Valentinos Neophytou BEng (Hons), MSc
Page 21 of 61

22. Design notes for Seismic Assessment to Eurocode 8 - Part 3
usual practice at the time of
In the latter case, limited in-situ
In the latter case, limited in-situ
construction;
inspections in the most critical
inspections in the most critical elements
In this case, limited inspections in
elements should be performed to
should be performed to check that the
the most critical elements should be
check that the available information
available information corresponds to the
performed to check that the
corresponds to the actual situation.
actual situation.
No direct information on the
Informationonthemechanicalproperti
Informationonthemechanicalpropertiesofth
mechanical properties of the
esoftheconstructionmaterialsis
econstructionmaterialsis available either
construction materials is available,
available either from extended in-
from comprehensive in-situ testing or
either from original design
situ testing or from original design
from original test reports. In this latter
specifications or from original test
specifications. In this latter case,
case, limited in-situ testing should be
reports. Default values should be
limited in-situ testing should be
performed.
assumed in accordance with
performed.
assumptions correspond to the actual
situation. Otherwise, more extensive
in-situ inspection is required.
Materials
standards at the time of construction,
accompanied by limited in-situ
testing in the most critical elements.
Valentinos Neophytou BEng (Hons), MSc
Page 22 of 61

23. Design notes for Seismic Assessment to Eurocode 8 - Part 3
KNOWLEDGE LEVELS
(EN 1998-3,cl.3.3.1)
Knowledge levels
(EN 1998-3,cl.3.3.1)
Geometry: The properties
of the structural system, and
of such non-structural
elements (e.g. masonry infill
panels) as may affect
structural response
Details: These include the amount and
detailing of reinforcement in reinforced
concrete, connections between steel
members, the connection of floor
diaphragms to lateral resisting structure,
the bond and mortar jointing of masonry
and the nature of any reinforcing
elements in masonry
Material: The mechanical
properties of the constituent
materials
Choose the
knowledge level
based on the
factors above
Limited knowledge
KL1
Normal knowledge
KL2
Full knowledge
KL3
DETAILS
DETAILS
DETAILS
Simulated design in
accordance with relevant
practice
and
From limited in-situ
inspection
From incomplete original
detailed construction
drawings with limited in-situ
inspection
or
From extended in-situ
inspection
From original detailed
construction drawings with
limited in-situ inspection
or
From comprehensive insitu inspection
MATERIALS
MATERIALS
Default values in
accordance with standards
of the time of construction
and
From limited in-situ testing
From original design
specifications with limited
in- situ testing
or
From extended in-situ
testing
Valentinos Neophytou BEng (Hons), MSc
MATERIALS
From original test reports
with limited in- situ testing
or
From comprehensive insitu testing
Page 23 of 61

24. Design notes for Seismic Assessment to Eurocode 8 - Part 3
LEVEL OF INSPECTION
(EN1998-3,cl.3.4.4)
YES
Is the Knowledge
level
KL1 ?
Details & Materials
Does the spot check agree
with the drawings/
assumptions ?
Note: if the masonry infill
walls are considered in
the model, certain
sampling and testing for
shear and compressive
strength and for Elastic
Modulus make sense
NO
NO
YES
Inspection: 20% detail
check
Testing: 1 sample per
floor (beam/column,wall)
Is the Knowledge
level
KL2 or KL3 ?
KL2
KL3
Details
YES
Details
Does the spot check agree
with the drawings/ Are the
drawing available?
Does the spot check agree
with the drawings/ Are the
drawing available?
NO
YES
Limited
Extended
Limited
Comprehesive
Inspection: 20% detail
check
Inspection: 50% detail
check
Inspection: 20% detail
check
Inspection: 80% detail
check
Materials
Material properties are
derived either from original
specification or through in
Specifictions
situ sampling
NO
Materials
Material properties are
derived either past test
reports or through in situ
sampling
Sampling
Test Reports
Limited
Extended
Limited
Comprehesive
Testing: 1 sample per
floor (beam/column,wall)
Testing: 2 sample per
floor (beam/column,wall)
Testing: 1 sample per
floor (beam/column,wall)
Testing: 3 sample per
floor (beam/column,wall)
Valentinos Neophytou BEng (Hons), MSc
Sampling
Page 24 of 61

25. Design notes for Seismic Assessment to Eurocode 8 - Part 3
SELECTED KNOWLEDGE LEVEL RELATED TO COST/PROCESS OF
INSPECTION
Low cost/process
LIMITED KNOWLEDGE LEVEL
Medium cost/process
NORMAL KNOWLEDGE LEVEL
High cost/process
FULL KNOWLEDGE LEVEL
SELECTED KNOWLEDGE LEVEL RELATED TO COST SAVING OF
RETROFITTING
High cost
LIMITED KNOWLEDGE LEVEL
Medium cost
NORMAL KNOWLEDGE LEVEL
Low cost
FULL KNOWLEDGE LEVEL
Valentinos Neophytou BEng (Hons), MSc
Page 25 of 61

26. Design notes for Seismic Assessment to Eurocode 8 - Part 3
VALUES OF CONFIDENCE FACTOR
(EN1998-3,cl.3.3.1)
CONFIDENCE FACTOR
(CF)
(EN1998-3,cl.3.3.1(4))
Limited knowledge
KL1
Normal knowledge
KL2
Full knowledge
KL3
CF=1.4
CF=1.2
CF=1.0
Note: If the existing member has been strengthened the “Confidence factor” (CF) is applied only on its old
material.
Note: The “Confidence factor” (CF) is applied to each old materials (steel, concrete, infill masonry).
ANALYSIS TYPE
(EN1998-3,cl.3.3.1)
ANALYSIS TYPE
(EN1998-3,cl.3.3.1(4))
YES
Lateral force (LF)
or
Modal Response Spectrum
(MRS)
(More conservative)
Valentinos Neophytou BEng (Hons), MSc
Is the Knowledge
level
KL1 ?
NO
Lateral force (LF)
or
Modal Response Spectrum
(MRS)
Or
Non-linear analysis
(Pushover/Time history)
(Less conservative)
Page 26 of 61

27. Design notes for Seismic Assessment to Eurocode 8 - Part 3
LATERAL FORCE ANALYSIS REQUIREMENTS (LFA)
(EN1998-1-1cl. & EN1998-3,cl.4.4.2)
HORIZONTAL ELASTIC RESPONSE SPECTRUM
(ΕΝ1998-1-1,cl.3.2.2.2)
0 ≤ 𝑇 ≤ 𝑇 𝐵: 𝑆 𝑒 𝑇 = 𝑎 𝑔 ∙ 𝑆 ∙ 1 +
𝑇
𝑇𝐵
∙ 𝜂 ∙ 2,5 − 1
(ΕΝ1998-1-1,Eq. 3.2)
𝑇 𝐵 ≤ 𝑇 ≤ 𝑇 𝐶 : 𝑆 𝑒 𝑇 = 𝑎 𝑔 ∙ 𝑆 ∙ 𝜂 ∙ 2.5
(ΕΝ1998-1-1,Eq. 3.3)
𝑇 𝐶 ≤ 𝑇 ≤ 𝑇 𝐷 : 𝑆 𝑒 𝑇 = 𝑎 𝑔 ∙ 𝑆 ∙ 𝜂 ∙ 2.5
𝑇𝐶
𝑇 𝐷 ≤ 𝑇 ≤ 4𝑠: 𝑆 𝑒 𝑇 = 𝑎 𝑔 ∙ 𝑆 ∙ 𝜂 ∙ 2.5
𝑇𝐶 𝑇𝐷
𝑇2
(ΕΝ1998-1-1,Eq. 3.4)
𝑇
(ΕΝ1998-1-1,Eq. 3.5)
Damping viscous: ξ=5%
Damping correction factor η: 𝜂 =
10/ 5 + 𝜉 ≥ 0.55
Design ground acceleration on type A ground: ag=γI*agR
Parameters of Type 1 elastic response spectrum (Large magnitude M>5.5Hz)
(CYS NA EN1998-1-1,table 3.2)
Ground
Type
A
B
C
D
E
S
TB (s)
TC (s)
TD (s)
1.0
1.2
1.15
1.35
1.4
0.15
0.15
0.20
0.20
0.15
0.4
0.5
0.6
0.8
0.5
2.0
2.0
2.0
2.0
2.0
Valentinos Neophytou BEng (Hons), MSc
Page 27 of 61

28. Design notes for Seismic Assessment to Eurocode 8 - Part 3
VERTICAL ELASTIC RESPONSE SPECTRUM
(ΕΝ1998-1-1,cl.3.2.2.3)
The vertical component of seismic action is taken into account if the design ground acceleration in the vertical
direction, avg, exceeds 0.25g, and even then only in the following cases:

for horizontal structural member spanning 20m or more,

for horizontal cantilever components longer than 5m,

for beams supporting columns,

in based-isolated structures.
0 ≤ 𝑇 ≤ 𝑇 𝐵 : 𝑆 𝑣𝑒 𝑇 = 𝑎 𝑣𝑔 ∙ 1 +
𝑇
𝑇𝐵
∙ 𝜂 ∙ 3,0 − 1
(ΕΝ1998-1-1,Eq. 3.8)
𝑇 𝐵 ≤ 𝑇 ≤ 𝑇 𝐶 : 𝑆 𝑣𝑒 𝑇 = 𝑎 𝑣𝑔 ∙ 𝜂 ∙ 3.0
(ΕΝ1998-1-1,Eq. 3.9)
𝑇 𝐶 ≤ 𝑇 ≤ 𝑇 𝐷 : 𝑆 𝑣𝑒 𝑇 = 𝑎 𝑣𝑔 ∙ 𝜂 ∙ 3.0
𝑇𝐶
𝑇 𝐷 ≤ 𝑇 ≤ 4𝑠: 𝑆 𝑣𝑒 𝑇 = 𝑎 𝑣𝑔 ∙ 𝜂 ∙ 3.0
𝑇𝐶 𝑇𝐷
𝑇2
(ΕΝ1998-1-1,Eq. 3.10)
𝑇
(ΕΝ1998-1-1,Eq. 3.11)
Damping viscous: ξ=5%
Damping correction factor η: 𝜂 =
10/ 5 + 𝜉 ≥ 0.55
Design ground acceleration on type A ground: ag=γI*agR
Design ground acceleration in vertical direction: avg = avg/ag*agR*γI
Note: the value of S is not used in the above expression cause the vertical ground motion is not very much
affected by the underlying ground condition
Parameters values of vertical elastic response spectra (Large magnitude M>5.5Hz)
(CYS NA EN1998-1-1,cl NA2.8)
Spectrum
avg/ag
TB (s)
TC (s)
TD (s)
Type 1
0.90
0.05
0.15
1.0
Valentinos Neophytou BEng (Hons), MSc
Page 28 of 61

29. Design notes for Seismic Assessment to Eurocode 8 - Part 3
COMBINATION OF SEISMIC MASS
(EN 1998-1-1,cl.3.2.4)
Storey
φ
Roof
1,0
Storeys with correlated occupancies
0.8
Independently occupied storeys
0.5
Type of Variable action
Categories A-C1
Categories A-F1
1.0
Category
Specific Use
ψ2
A
Domestic and residential
0.3
B
Office
0.3
C
Areas for Congregation
0.6
D
Shopping
0.6
E
Storage
0.8
F
Traffic < 30 kN vehicle
0.6
G
Traffic < 160 kN vehicle
0.3
H
Roofs
0
Snow, altitude < 1000 m
0
Wind
0
Values
References
𝜓Ei = 𝜙 ∙ 𝜓2i
ΕΝ1998-1-1,Eq. 4.2
Requirements
Combination coefficient for variable
action
Combination of seismic mass
Requirements
Gk,j +
𝜓Ei Qk,i
Values
ΕΝ1998-1-1,Eq. 3.17
References
ST = 1.0 (S = S * ST)
If γI > 1.0 (i.e. III & IV)
Amplification factor
for Slopes <15o
EN1998-5, Annex A
Cliffs height <30m
ST = 1.2 (S = S * ST)
Valentinos Neophytou BEng (Hons), MSc
EN1998-5, Annex A
Page 29 of 61

30. Design notes for Seismic Assessment to Eurocode 8 - Part 3
If γI > I (i.e. III & IV)
for Slopes 15o ≤ slope ≤ 30o Cliffs
height <30m
ST = 1.4 (S = S * ST)
If γI > 1.0 (i.e. III & IV)
for Slopes slope > 30o
EN1998-5, Annex A
Cliffs height <30m
(Bisch etal, 2011 – Lisbon)
Requirements
Values
References
YES / NO
ΕΝ1998-1-1,table 4.1
Regular in elevation
YES
ΕΝ1998-1-1,table 4.1
Ground acceleration
0.10-0.25g
Regular in plan
Spectrum type
TYPE 1
(Large magnitude M>5.5Hz)
CYS NA EN1998-1-1:Seismic
zonation map
EN1998-1-1,cl.3.2.2.2(2)P
A,B,C,D,E
Ground type
Normally type B or C can be used
EN1998-1-1,cl.3.1.2(1)
normal condition
Lower bound factor for the horizontal
λ = 0.85 if T1 ≤ 2TC and more than 2
design spectrum
storey
EN1998-1-1,cl.4.3.3.2.2(1Ρ)
λ=1.0 in all other case
Damped elastic response spectrum
Fundamental period
Valentinos Neophytou BEng (Hons), MSc
ξ = 5%
T1≤4Tc
T1≤2,0s
EN1998-1-1,cl.3.2.2.2(1)P
EN1998-1-1,cl.4.3.3.2.1(2)
Page 30 of 61

31. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Accidental eccentricity
See table below
Fb=Sd(T1).mass.λ
Base shear
Horizontal seismic forces (according
EN1998-1-1,cl.4.3.2
(EN1998-1-1,cl.4.3.3.2.2)
Fi = Fb ∙
to height of the masses)
zi ∙ mi
zj ∙ mj
(EN 1998-1-1:2004, Eq. 4.11)
𝐹𝑖 = 𝛿 ∙ 𝐹𝑖
(Fi see above)
Accidental torsional effects
3D
EN1998-1-1,cl.4.3.3.2.4(1)
Where:
𝛿 = 1 + 0.6
If the accidental torsional effects as
𝑥
𝐿𝑒
𝑀 𝑎𝑖 = ∓𝑒 𝑎𝑖 ∙ 𝛿𝐹𝑖
shown in table below (EN199811,cl.4.3.2(1)P) is not taken into
Where:
2D
𝑒 𝑎𝑖 = ∓0.10𝐿 𝑖
(regular in plan)
Where
account the following rules can be
use
𝛿 = 1 + 1.2
EN1998-1-1,cl.4.3.3.2.4(2)
𝑥
𝐿𝑒
Accidental torsional effect
(EN1998-1-1,cl.4.3.2)
Asymmetric distribution of
Percentage of accidental
eccentricity
Geometry of model (3D/2D)
mass
(i.e. infill walls)
(Regular/Irregular)
5%
3D
Regular
10%
3D
Irregular
20%
2D
-
Requirements
Values
References
Torsional moment
Valentinos Neophytou BEng (Hons), MSc
𝑀 𝑎𝑖 = ∓𝑒 𝑎𝑖 ∙ 𝐹𝑖
For eai see the table above
EN1998-1-1,cl.4.3.3.3.3(1)
Page 31 of 61

32. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Load case name
Direction and Eccentricity
% Eccentricity
EQXA
X Dir + Eccen. Y
As above
EQYA
X Dir – Eccen. Y
As above
EQXB
Y Dir + Eccen. X
As above
EQYB
Y Dir – Eccen. X
As above
Reference structure
Period T1
Exact formula for Single Degree of Freedom Oscillator. Mass M lumped at
top of a vertical cantilever of height H. Cantilever mass MB = 0.
T1 = 2π
Exact formula for Single Degree of Freedom Oscillator. Vertical cantilever
of height H and of total mass MB.
T1 = 2π
Exact formula for Single Degree of Freedom Oscillator. Mass M lumped at
top of a vertical cantilever of height H and of total mass MB.
T1 = 2π
MH 3
3EI
0.24MB H 3
3EI
M + 0.24MB H 3
3EI
Approximate Relationship (Eurocode 8).
Ct = 0,085 for moment resisting steel space frames Ct = 0,075 for
eccentrically braced steel frames
Ct = 0,050 for all other structures
T1 = Ct H 3/4
H building height in m measured
from foundation or top of rigid
basement.
Approximate Relationship (Eurocode 8).
d : elastic horizontal displacement of top of building in m under gravity
T1 = 2 d
loads applied horizontally.
Valentinos Neophytou BEng (Hons), MSc
Page 32 of 61

33. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Modal Response Spectrum Analysis requirements (MRSA)
(EN1998-1-1cl. & EN1998-3,cl.4.4.2)
Requirements
Values
Horizontal elastic response spectrum
As above – see LFA
Vertical elastic response spectrum
As above – see LFA
Amplification factor
As above – see LFA
Seismic mass
As above – see LFA
Requirements
Values
YES/NO
Structural model
Ground acceleration
Spectrum type
ΕΝ1998-1-1,table 4.1
2D/3D
Regular in elevation
ΕΝ1998-1-1,table 4.1
NO
Regular in plan
References
EN1998-1-1,cl.4.2.3.1(3)P
0.10-0.25g
TYPE 1
(Large magnitude M>5.5Hz)
CYS NA EN1998-1-1:Seismic
zonation map
EN1998-1-1,cl.3.2.2.2(2)P
A,B,C,D,E
Ground type
Normally type B or C can be used
EN1998-1-1,cl.3.1.2(1)
normal condition
ξ = 5%
Accidental eccentricity
EN1998-1-1,cl.3.2.2.2(1)P
See table below
Damped elastic response spectrum
EN1998-1-1,cl.4.3.2
ΣMx ≥ 90% of total mass
ΣMy ≥ 90% of total mass
Effective modal modes
Mx ≥ 5% of total mass
EN1998-1-1,cl.4.3.3.1(3)
Mxy ≥ 5% of total mass
k ≥3.√n
Minimum number of modes
(if eigenvalue analysis capture)
k: is the number of modes
EN1998-1-1,cl.4.3.3.1(5)
n: is the number of storey
Valentinos Neophytou BEng (Hons), MSc
Page 33 of 61

34. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Tk ≤ 0.20sec
Tk: is the period of vibration of mode
k
Period of vibration
EN1998-1-1,cl.4.3.3.1(5)
At least one natural period should be
below 0.20s
Fundamental period
Tj ≤ 0.9 Ti
SRSS
Tj ≥ 0.9 Ti
CQC
EN1998-1-1,cl.4.3.3.2.1(2)
𝑀 𝑎𝑖 = ∓𝑒 𝑎𝑖 ∙ 𝐹𝑖
3D
For eai see the table
EN1998-1-1,cl.4.3.3.3.3(1)
below
𝑀 𝑎𝑖 = ∓𝑒 𝑎𝑖 ∙ 𝛿𝐹𝑖
Torsional moment
Where:
2D
𝑒 𝑎𝑖 = ∓0.10𝐿 𝑖
(regular in
EN1998-1-1,cl.4.3.3.2.4(2)
Where
plan)
𝛿 = 1 + 1.2
𝑥
𝐿𝑒
Accidental torsional effect
(EN1998-1-1,cl.4.3.2)
Percentage of accidental
eccentricity
Asymmetric distribution of mass
Geometry of model (3D/2D)
(i.e. infill walls)
(Regular/Irregular)
5%
3D
Regular
10%
3D
Irregular
20%
2D
-
Valentinos Neophytou BEng (Hons), MSc
Page 34 of 61

35. Design notes for Seismic Assessment to Eurocode 8 - Part 3
q – factor approach analysis requirements
(ΕΝ1998-1-1,cl.3.2.2.2)
Design spectrum of elastic analysis
(ΕΝ1998-1-1,cl.3.2.2.5)
0 ≤ 𝑇 ≤ 𝑇 𝐵: 𝑆 𝑑 𝑇 = 𝑎 𝑔 ∙ 𝑆 ∙
𝑇 𝐵 ≤ 𝑇 ≤ 𝑇 𝐶: 𝑆 𝑑 𝑇 = 𝑎 𝑔 ∙ 𝑆 ∙
2
3
+
𝑇
𝑇𝐵
∙
2.5
𝑞
2
−3
(ΕΝ1998-1-1,Eq. 3.13)
2.5
𝑇 𝐶 ≤ 𝑇 ≤ 𝑇 𝐷: 𝑆 𝑑 𝑇 = 𝑎 𝑔 ∙ 𝑆 ∙
(ΕΝ1998-1-1,Eq. 3.14)
𝑞
2.5 𝑇 𝐶
𝑞 𝑇
≥ 𝛽 ∙ 𝑎𝑔
(ΕΝ1998-1-1,Eq. 3.15)
𝑇 𝐷 ≤ 𝑇 ≤ 4𝑠: 𝑆 𝑑 𝑇 = 𝑎 𝑔 ∙ 𝑆 ∙
2.5
𝑞
𝑇𝐶 𝑇𝐷
𝑇2
≥ 𝛽 ∙ 𝑎𝑔
(ΕΝ1998-1-1,Eq. 3.5)
Design ground acceleration on type A ground:
ag=γI*agR
Lower bound factor for the horizontal spectrum: β=0.2
A value of q =1.5 for concrete structures (regardless of the structural system)
A value of q = 2.0 for steel structures (regardless of the structural system)
Parameters of Type 1 elastic response spectrum (Large magnitude M>5.5Hz)
(CYS NA EN1998-1-1,table 3.2)
Ground
Type
A
B
C
D
E
S
TB (s)
TC (s)
TD (s)
1.0
1.2
1.15
1.35
1.4
0.15
0.15
0.20
0.20
0.15
0.4
0.5
0.6
0.8
0.5
2.0
2.0
2.0
2.0
2.0
Valentinos Neophytou BEng (Hons), MSc
Page 35 of 61

36. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Vertical elastic design spectrum
(ΕΝ1998-1-1,cl.3.2.2.5(5))
The vertical component of seismic action is taken into account if the design ground acceleration in the
vertical direction, avg, exceeds 0.25g, and even then only in the following cases:

for horizontal structural member spanning 20m or more,

for horizontal cantilever components longer than 5m,

for beams supporting columns,

in based-isolated structures.
. 0 ≤ 𝑇 ≤ 𝑇 𝐵 : 𝑆 𝑑 𝑇 = 𝑎 𝑣𝑔 ∙
2
𝑇 𝐵 ≤ 𝑇 ≤ 𝑇 𝐶 : 𝑆 𝑑 𝑇 = 𝑎 𝑣𝑔 ∙
2.5
𝑇 𝐶 ≤ 𝑇 ≤ 𝑇 𝐷 : 𝑆 𝑑 𝑇 = 𝑎 𝑣𝑔 ∙
3
+
𝑇
𝑇𝐵
∙
2.5
𝑞
2
−3
(ΕΝ1998-1-1,Eq. 3.13)
(ΕΝ1998-1-1,Eq. 3.14)
𝑞
2.5 𝑇 𝐶
𝑞 𝑇
≥ 𝛽 ∙ 𝑎 𝑣𝑔
(ΕΝ1998-1-1,Eq. 3.15)
𝑇 𝐷 ≤ 𝑇 ≤ 4𝑠: 𝑆 𝑑 𝑇 = 𝑎 𝑣𝑔 ∙
2.5
𝑞
𝑇𝐶 𝑇𝐷
𝑇2
≥ 𝛽 ∙ 𝑎 𝑣𝑔
(ΕΝ1998-1-1,Eq. 3.5)
Design ground acceleration on type A ground: ag=γI*agR
Design ground acceleration in vertical direction: avg = avg/ag*agR*γI
For the vertical component of the seismic action the design spectrum is given by expressions (3.13) to
(3.16), with the design ground acceleration in the vertical direction, avg replacing ag, S taken as being
equal to 1,0 and the other parameters as defined in 3.2.2.3.
Parameters values of vertical elastic response spectra
(CYS NA EN1998-1-1,cl NA2.8)
Spectrum
avg/ag
TB (s)
TC (s)
TD (s)
Type 1
0.90
0.05
0.15
1.0
Special provisions:

For the vertical component of the seismic action a behaviour factor q up to to 1,5 should generally
be adopted for all materials and structural systems.
Valentinos Neophytou BEng (Hons), MSc
Page 36 of 61

37. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Requirements
Values
Amplification factor
As above – see LFA
Seismic mass
As above – see LFA
Analysis requirements
As above – see MRSA
Accidental eccentricity
As above – see MRSA
Regular in plan
As above – see MRSA
Regular in elevation
As above – see MRSA
Structural model
As above – see MRSA
Ground acceleration
As above – see MRSA
Spectrum type
As above – see MRSA
Ground type
As above – see MRSA
Damped elastic response spectrum
As above – see MRSA
Accidental eccentricity
As above – see MRSA
Effective modal modes
As above – see MRSA
Minimum number of modes
As above – see MRSA
Fundamental period
As above – see MRSA
Torsional moment
As above – see MRSA
Accidental torsional effect
As above – see MRSA
Valentinos Neophytou BEng (Hons), MSc
Page 37 of 61

38. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Linear Analysis - Requirements from EN1998-3
(EN1998-3,cl.4.4.2(1)P)
Requirements
Values
Ductile mechanism (flexure)
Brittle mechanism (Shear)
Demand
Capacity
Demand
Capacity
(Di)
(Ci)
(Di)
(Ci)
Acceptability of linear model
(for checking of ρi =
From
analysis.
Use mean
values of
properties
Di
Ci
Verifications (if LM accepted)
values)
In term of
strength.
Use mean values
of properties.
If ρi < 1: from
analysis
strength.
Verifications (if LM accepted)
If ρi > 1: from
Ratio between demand and
capacity
In term of
EN1998-3cl.4.4.2(1)P
From
analysis.
strength.
Use mean values
of properties
divided by CF
In term of
equilibrium with
strength of
ductile e/m.
Use mean values
Use mean values
of properties
divided by CF and
by partial factor
of properties
multiplied by
CF.
Dseismic : is bending moment at the end member due to the seismic action
and the concurrent gravity load.
Cgravity : is the corresponding moment resistance, calculated on the basis of
the axial force due to gravity load alone and using mean-value properties
of old material from in-situ test.
Note: ρi=Dseismic/Cgravity
Valentinos Neophytou BEng (Hons), MSc
Page 38 of 61

39. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Value of the ratio
ρmax/ρmin
ρmax/ρmin = 2.5
(EN1998-3,cl.4.4.2(1P)
Valentinos Neophytou BEng (Hons), MSc
Page 39 of 61

40. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Combination of seismic action
(EN1998-1-1cl. & EN1998-3,cl.4.4.2)
Seismic load combination for “Modal Analysis/Pushover”
SEISMIC 1.
DL + ψEiLL + EQX + 0.3EQY
SEISMIC 2.
DL + ψEiLL + EQX – 0.3EQY
SEISMIC 3.
DL + ψEiLL - EQX + 0.3EQY
SEISMIC 4.
DL + ψEiLL - EQX – 0.3EQY
SEISMIC 5.
DL + ψEiLL + EQY + 0.3EQX
SEISMIC 6.
DL + ψEiLL + EQY – 0.3EQX
SEISMIC 7.
DL + ψEiLL - EQY + 0.3EQX
SEISMIC 8.
DL + ψEiLL - EQY – 0.3EQX
Seismic load combination for “Lateral force Analysis/Pushover”
SEISMIC 1.
DL + ψEiLL + EQXA + 0.3EQY
SEISMIC 2.
DL + ψEiLL + EQXA – 0.3EQY
SEISMIC 3.
DL + ψEiLL - EQXA + 0.3EQY
SEISMIC 4.
DL + ψEiLL - EQXA – 0.3EQY
SEISMIC 5.
DL + ψEiLL + EQYA + 0.3EQX
SEISMIC 6.
DL + ψEiLL + EQYA – 0.3EQX
SEISMIC 7.
DL + ψEiLL - EQYA + 0.3EQX
SEISMIC 8.
DL + ψEiLL - EQY – 0.3EQX
SEISMIC 9.
DL + ψEiLL + EQX + 0.3EQY
SEISMIC 10.
DL + ψEiLL + EQX – 0.3EQY
SEISMIC 11.
DL + ψEiLL - EQX + 0.3EQY
SEISMIC 12.
DL + ψEiLL - EQX – 0.3EQY
SEISMIC 13.
DL + ψEiLL + EQY + 0.3EQX
SEISMIC 14.
DL + ψEiLL + EQY – 0.3EQX
SEISMIC 15.
DL + ψEiLL - EQY + 0.3EQX
SEISMIC 16.
DL + ψEiLL - EQY – 0.3EQX
Valentinos Neophytou BEng (Hons), MSc
Page 40 of 61

41. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Non-linear Analysis – Pushover Analysis requirements
(EN1998-1-1cl. & EN1998-3,cl.4.4.2)
Requirements
Values
References
Regular in plan
YES/NO
ΕΝ1998-1-1,table 4.1
Regular in elevation
YES/NO
ΕΝ1998-1-1,table 4.1
2D/3D
EN1998-1-1,cl.4.3.3.1(9&10)P
Structural model
Ground acceleration
Spectrum type
CYS NA EN1998-1-1:Seismic
0.10-0.25g
zonation map
TYPE 1
(Large magnitude M>5.5Hz)
EN1998-1-1,cl.3.2.2.2(2)P
A,B,C,D,E
Ground type
Normally type B or C can be used
EN1998-1-1,cl.3.1.2(1)
normal condition
Cracked elements
50% of the stiffness
EN1998-1-1,cl.4.3.1(7)
Material properties
Use mean values
EN1998-1-1,cl.4.3.3.4.1(4)
Seismic action
Apply to the ∓ direction
EN1998-1-1,cl.4.3.3.4.1(7)P
Lateral Force Analysis
Lateral loads derived from
or
EN1998-1-1,cl.4.3.3.4.2.2(1)
Modal Response Spectrum Analysis
Determination of the period
for SDOF
𝑇 = 2𝜋
𝑚∙ 𝑑𝑦
𝐹𝑦
EN1998-1-1,Eq.B.7
Determination of the
Target displacement for
SDOF
𝑇
𝑑 𝑒 = 𝑆 𝑒 (𝑇)
2𝜋
2
EN1998-1-1,Eq.B.8
Accidental torsional effect
(EN1998-1-1,cl.4.3.2)
Percentage of accidental
eccentricity
Geometry of model (3D/2D)
Valentinos Neophytou BEng (Hons), MSc
Asymmetric distribution of mass in
plan
Page 41 of 61

42. Design notes for Seismic Assessment to Eurocode 8 - Part 3
(i.e. infill walls)
(Regular/Irregular)
5%
3D
Regular
10%
3D
Irregular
20%
2D
-
Valentinos Neophytou BEng (Hons), MSc
Page 42 of 61

43. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Non linear Analysis - Requirements from EN1998-3
(EN1998-3,cl.4.4.2(1)P)
Requirements
Values
Ductile mechanism (flexure)
Brittle mechanism (Shear)
Demand
Ratio between demand
Capacity
Demand
Capacity
(Di)
(Ci)
(Di)
(Ci)
and capacity
From analysis.
In term of
From analysis.
In term of strength.
EN1998-3cl.4.4.2(1)P
Use mean
deformation.
Use mean
Use mean values of
values of
Use mean values
values of
properties divided by
properties in
of properties
properties in
CF and by partial
model.
divided by CF.
model.
factor.
Plastic hinges
X & Y – direction (check separately)
∑ M Rc > ∑ M Rb , then plastic hinges will likely develop in beams and,
Case 1: At beams
consequently, only the beams should be considered for the evaluation of
ρmax and ρmin.
∑ M Rc < ∑ M Rb , then plastic hinges will likely develop in columns and,
Case 2: At Columns
thereby, only the columns should be considered for the evaluation of ρmax
and ρmin.
Lateral load
(EN1998-1-1,cl. 4.3.3.4.2.2(1))
Load pattern
Description
A “uniform pattern”, corresponding to uniform unidirectional lateral
Uniform load pattern
accelerations (i.e. Φi = 1) . It attempts to simulate the inertia forces in a
potential soft-storey mechanism, limited in all likelihood to the bottom
storey, with the lateral drifts concentrated there and the storeys above
moving laterally almost as a rigid body.
Valentinos Neophytou BEng (Hons), MSc
Page 43 of 61

44. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Uniform load pattern
A “modal pattern”, simulating the inertia forces of the1st mode in the
horizontal direction in which the analysis is carried out. This pattern is
meant to apply in the elastic regime and during the initial stages of the
plastic mechanism development, as well as in a full-fledged beam-sway
mechanism
Modal load pattern
Modal load pattern
Valentinos Neophytou BEng (Hons), MSc
Page 44 of 61

45. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Capacity curve
(EN1998-1-1,cl. 4.3.3.4.2.3(1))
Relation between base shear force and the control displacement
Capacity curve (for each
analysis see below)
1. Pushover curve ends until a terminal point at 1.5 times the
“target displacement”.
Procedure for determination of the target displacement for nonlinear static (pushover) analysis
(EN1998-1,cl.Annex B)
Requirements
Values
Φi = 1
References
Uniform pattern
EN1998-1,cl.B.1
Normalized displacement
Φi =
Modal pattern
Calculated from Modal analysis
Natural period
T calculated from linear elastic analysis
-
Normalized lateral forces
𝐹 𝑖 = 𝑚 𝑖 Φi
EN1998-1,Eq.B.1
Mass of an equivalent
SDOF
𝑚∗ =
Valentinos Neophytou BEng (Hons), MSc
𝑚𝑖 𝜙𝑖 =
𝐹𝑖
EN1998-1,Eq.B.2
Page 45 of 61

46. Design notes for Seismic Assessment to Eurocode 8 - Part 3
𝑚∗
Γ=
Transformation factor
𝑚 𝑖 Φi
=
2
𝐹𝑖
𝐹𝑖 2
𝑚𝑖
𝐹 𝑏 = 𝑆d(𝑇1) ⋅ 𝑚 ⋅ λ
Base shear
EN1998-1,Eq.B.3
EN1998-11,cl.3.2.2.2
Force of SDOF
𝐹∗ =
𝐹𝑏
Γ
EN1998-1,Eq.B.4
Displacement of SDOF
𝑑∗ =
𝑑𝑛
Γ
EN1998-1,Eq.B.5
∗
𝑑𝑦 = 2
Yield displacement of the
idealised SDOF system
𝑑𝑚
∗
𝐸 𝑚∗
− ∗
𝐹𝑦
Note: The maximum displacement of structure is
EN1998-1,Eq.B.6
taken from the roof level at the node of centre of mass.
The top of a penthouse should not be considered as the
roof.
𝑇 = 2𝜋
Period
𝑚∗ ∙ 𝑑 𝑦 ∗
𝐹𝑦
EN1998-1,Eq.B.7
Elastic acceleration
response spectrum, Se(T*)
See section above “LFA”
Target displacement of the
structure with period T*
𝑑 𝑒𝑡
Valentinos Neophytou BEng (Hons), MSc
∗
𝑇∗
= 𝑆𝑒(𝑇)
2𝜋
∗
-
2
EN1998-1,Eq.B.8
Page 46 of 61

47. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Target displacement
Short period range
EN1998-1,cl.B.5
(T* < Tc)
𝐹𝑦 ∗
𝑚∗
𝐹𝑦 ∗
𝑚∗
≥ 𝑆 𝑒 𝑇∗
𝑑 𝑡 ∗ ≥ 𝑑 𝑒𝑡 ∗
< 𝑆 𝑒 𝑇∗
𝑑 𝑡∗ =
𝑞𝑢 =
𝑑 𝑒𝑡 ∗
𝑞𝑢
1+ 𝑞𝑢 −1
𝑇𝐶
𝑇∗
≥ 𝑑 𝑒𝑡 ∗
𝑆 𝑒 𝑇 ∗ 𝑚∗
𝐹𝑦 ∗
Target displacement
EN1998-1,cl.B.5
Medium and long period
range (T* ≥ Tc)
𝑑 𝑡 ∗ = det ∗ = 𝑆𝑒(𝑇)∗
Valentinos Neophytou BEng (Hons), MSc
𝑇∗ 2
2𝜋
(≤3det*)
Page 47 of 61

48. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Target displacement of
dt =Γdt*
MDOF
EN1998-1,Eq.B.13
Torsional effects
(EN1998-1-1,cl.4.3.3.4.2.7)
Requirements
2D/3D
Description
References
This rule applied to the following
structural system:
Torsionally flexible structural type (i.e.
rx < Is see EN1998-1-1,cl.4.2.3.2, or, a
structure with a predominantly torsional
1st or 2nd mode of vibration in one of the
Torsional effects
requirements
3D model
two orthogonal horizontal direction).
-
Displacement at the stiff/strong
EN1998-11,cl.4.3.3.4.2.7(1)P
side are under estimated compared
to the flexible weak side in plan
(i.e. is the side which developed
smaller displacement under static
load parallel to it) shall be
increased
𝑀 𝑎𝑖 = ∓𝑒 𝑎𝑖 ∙ 𝛿𝐹𝑖
Where:
Torsional effects
requirements
2D model
(regular
𝑒 𝑎𝑖 = ∓0.10𝐿 𝑖
(see table above)
in plan)
Where
𝑥
𝛿 = 1 + 1.2
𝐿𝑒
EN1998-11,cl.4.3.3.2.4(2)
EN1998-1EN1998-1-
1,cl.4.3.3.4.2.7(3)
1,cl.4.3.2(1)P
Procedure for determine the increased displacement of strong/stiff side
Procedure for determine the increased displacement of strong/stiff side can be found in the Designer’s
Guide to EN1998-1 and EN1998-5 in p. 57
Valentinos Neophytou BEng (Hons), MSc
Page 48 of 61

49. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Number of Analysis required (Pushover)
X & Y – main directions
Y - direction
“modal” towards (+) positive Y
“modal” towards (-) negative X
“modal” towards (-) negative Y
“uniform” towards (+) positive X
“uniform” towards (+) positive Y
“uniform” towards (-) negative X
Analysis number
X – direction
“modal” towards (+) positive
Directions
“uniform” towards (-) negative Y
Valentinos Neophytou BEng (Hons), MSc
Page 49 of 61

50. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Modeling Aspects
(EN1998-1-1,cl.4.3.1)
Requirements
Secondary
elements
Material properties
Lateral components
Values
References
The strength and stiffness of secondary seismic
elements, against lateral actions may in general be
EN1998-3,cl.4.3(3)P
neglected in the analysis
Use mean values of material properties
All lateral components should be connected by
horizontal diaphragms
EN1998-3,cl.4.3(5)P
EN1998-1-1,cl.4.3.1(3)
Floor diaphragms may taken as being rigid in their
planes, mass and moments inertia may be lumped at
the centre of gravity.
Neglect the rigid diaphragm assumption for the
following cases:
Floor diaphragms
1. not compact configuration and plan view far
from rectangular.
EN1998-1-1,cl.4.3.1(4)
2. large openings in floor slabs, due to internal
patios or stairways.
3. large distance between strong and stiff vertical
elements compared to the transverse dimension
of the diaphragm.
Structural
Criteria for regularity are play significant role to the
regularity
type of modeling and analysis
EN1998-1-1,cl.4.3.1(5)
No use of the modification for un-crack cross-section
(50% EI). Not OK in displacement-based assessment
Crack analysis
(unconservative for displacement demands). OK in
EN1998-1-1,cl.4.3.1(6&7)
force-based design of new buildings (conservative
for force
Infill walls which contribute significally to the lateral
Infill walls
stiffness and resistance of the building should be taken
EN1998-1-1,cl.4.3.1(8)
into account
Valentinos Neophytou BEng (Hons), MSc
Page 50 of 61

51. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Foundation
The deformability of the foundation shall be taken into
account in the model
Valentinos Neophytou BEng (Hons), MSc
EN1998-1-1,cl.4.3.1(9)
Page 51 of 61

52. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Seismic assessment of Reinforced Concrete buildings
(EN1998-3,Annex A)
Partial factors
Requirements
Values
References
γs = 1.15
CYS EN1992-1-1,table 2.1
γc = 1.5
CYS EN1992-1-1,table 2.1
Permanent action
γG = 1.35
EN1990,cl.6.4.3.2
Variable action
γQ = 1.5
EN1990,cl.6.4.3.2
Partial factor for steel
reinforcement
Partial factor of concrete
Limit State of near collapse (NC)
Requirements
Values
Factor for structural
References
𝛾 𝑒𝑙 = 1.5 (primary members)
element
EN1998-3,cl.A.3.2.2(1)
𝛾 𝑒𝑙 = 1.0 (secondary members)
primary/secondary
Ratio moment/shear at
the end section
𝐿 𝑣 = 𝑀/𝑉
EN1998-3,cl.A.3.2.2(1)
𝑣=
Design axial force
Mechanical
reinforcement ratio of
the tension and
𝑁
𝑏 ∙ 𝑕 ∙ 𝑓𝑐
EN1998-3,cl.A.3.2.2(1)
Mechanical ratio
𝜔‫= ׳‬
𝜌1 + 𝜌 𝑣 𝑓 𝑦𝐿
𝑓𝑐
compression of
Valentinos Neophytou BEng (Hons), MSc
of tension
fc : uniaxial (cylindrical)
longitudinal
concrete strength (MPa)
reinforcement
Page 52 of 61

53. Design notes for Seismic Assessment to Eurocode 8 - Part 3
longitudinal
Mechanical ratio
reinforcement, ω,ω‫׳‬
𝜔=
𝜌2 𝑓 𝑦𝐿
𝑓𝑐
of compression
longitudinal
reinforcement
Modulus of Elasticity
𝐸 𝑐𝑚
(as for new members)
Concrete compressive
𝑓𝑐 𝑚
= 22
10
EN1998-3,cl.A.3.2.2(1)
𝑓𝑦𝑤 =
Stirrup Yield strength
Ratio of transverse
𝜌 𝑠𝑥 =
steel parallel to the
direction x of loading
Confinement
effectiveness factor
capacity
𝑓𝑦
𝐶𝐹
𝐴 𝑠𝑥
𝑏 𝑤 ∙ 𝑠𝑕
EN1998-3,cl.A.3.2.2(1)
sh : stirrup spacing
𝑠𝑕
𝑎 = 1−
2𝑏 𝑜
𝑠𝑕
1−
2𝑕 𝑜
Total chord rotation
𝜃 𝑢𝑚
EN1992-1-1,table 3.1
𝑓𝑐
𝐶𝐹
𝑓𝑐 =
strength
0.3
𝑏𝑖2
1−
6𝑕 𝑜 ∙ 𝑏 𝑜
EN1998-3,cl.A.3.2.2(1)
Elastic plus inelastic part
See the equation below: Beams & Columns (elastic plus inelastic part
1
=
0.016 ∙ 0. 3 𝑣
𝛾 𝑒𝑙
Total chord rotation
capacity
For cold-work brittle
𝑚𝑎𝑥 0.01; 𝜔‫׳‬
𝑓
𝑚𝑎𝑥 0.01; 𝜔 𝑐
𝐿𝑣
𝑚𝑖𝑛 9;
𝑕
𝜃 𝑢𝑚 = 0.58 ∙ 𝜃 𝑢𝑚
Walls:
0.35
25
𝑓 𝑦𝑤
𝑎𝜌 𝑠𝑥
𝑓𝑐
1.25100𝜌 𝑑
EN1998-3,cl.A.3.2.2(1)
𝜃 𝑢𝑚 =
𝜃 𝑢𝑚
1.6
EN1998-3,cl.A.3.2.2(1)
𝜃 𝑢𝑚 =
𝜃 𝑢𝑚
1.2
EN1998-3,cl.A.3.2.2(3)
steel
Members without
0.225
detail for earthquake
resistance
Total chord rotation
capacity
Valentinos Neophytou BEng (Hons), MSc
Plastic part
Page 53 of 61

54. Design notes for Seismic Assessment to Eurocode 8 - Part 3
See the equation below: Beams & Columns (elastic plus inelastic part
𝜃 𝑢𝑚
𝑝𝑙
1
=
0.0145 ∙ 0. 25 𝑣
𝛾 𝑒𝑙
𝑚𝑎𝑥 0.01; 𝜔‫׳‬
𝑚𝑎𝑥 0.01; 𝜔
0.3
𝑓𝑐
𝐿𝑣
𝑚𝑖𝑛 9,
𝑕
0.2
𝛾 𝑒𝑙 = 1.8 (primary members)
Factor for structural element
primary/secondary
𝛾 𝑒𝑙 = 1.0 (secondary members)
Total chord rotation capacity
Walls:
𝜃 𝑢𝑚
𝑝𝑙
Members without detail for
𝜃 𝑢𝑚 =
earthquake resistance
𝜃 𝑢𝑚
𝑓 𝑦𝑤
𝑎𝜌 𝑠𝑥
𝑓𝑐
1.275100𝜌 𝑑
EN1998-3,cl.A.3.2.2(2)
EN1998-3,cl.A.3.2.2(2)
EN1998-3,cl.A.3.2.2(2)
𝜃 𝑢𝑚
𝜃 𝑢𝑚 𝑝𝑙
, 𝜃 𝑢𝑚 =
1.2
1.2
EN1998-3,cl.A.3.2.2(3)
If 𝑙 𝑜 < 𝑙 𝑜𝑢 ,𝑚𝑖𝑛
Total chord rotation capacity
𝑝𝑙
25
𝜃 𝑢𝑚
2.0
𝜃 𝑢𝑚 =
For cold-work brittle steel
= 0.6 ∙ 𝜃 𝑢𝑚
0.35
𝑝𝑙
= 𝜃 𝑢𝑚
=>
EN1998-3,cl.A.3.2.2(4)
𝑙𝑜
𝑝𝑙
𝑙 𝑜𝑢 ,𝑚𝑖𝑛
Requirements for lamping zone of longitudinal bars
Actual lamping ratio
𝜌 = 2𝜌
(at the zone of
EN1998-3,cl.A.3.2.2(4)
overlapping)
𝑎1 =
1 − 𝑠 𝑕 1 − 𝑠 𝑕 𝑛 𝑟𝑒𝑠𝑡𝑟
∙
∙
2𝑏 𝑜
2𝑕 𝑜
𝑛 𝑡𝑜𝑡
nrestr : number of lapped longitudinal bars
Minimum lamping
length
laterally restrained by a stirrup corner or
cross-tie.
EN1998-3,cl.A.3.2.2(4)
ntot : total number of lapped longitudinal
bars along the cross-section perimeter.
𝑙 𝑜𝑢 ,𝑚𝑖𝑛 =
𝑑 𝑏𝑙 ∙ 𝑓 𝑦𝐿
1.05 + 14.5𝑎1 𝜌 𝑠𝑥
Valentinos Neophytou BEng (Hons), MSc
𝑓𝑦 𝑤
𝑓𝑐
∙
𝑓𝑐
Page 54 of 61

55. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Shear strength
𝐴𝑐 = 𝑏 𝑤 𝑑
Area of cross section
Concrete compressive
𝑓𝑐 =
strength
𝑓𝑐𝑘
𝛾𝐶
EN1992-1-1,cl.3.1.6(1)
𝛾 𝑒𝑙 = 1.15 (primary members)
Factor for structural
element
EN1998-3,cl.A.3.3.1(1)
EN1998-3,cl.A.3.3.1(1)
𝛾 𝑒𝑙 = 1.0 (secondary members)
primary/secondary
Contribution of
𝑉 𝑤 = 𝜌 𝑤 𝑏 𝑤 𝑧𝑓𝑦 𝑤
Rectangular
transverse reinforcement
𝑉𝑤 =
Circular
to shear resistance
Shear resistance after
flexural
EN1998-3,cl.A.3.3.1(1)
yielding,
𝜋 𝐴 𝑠𝑤
𝑓
𝐷 − 2𝑐
2 𝑠 𝑦𝑤
EN1998-3,cl.A.3.3.1(1)
EN1998-3,cl.A.3.3.1(1)
See below:
as
controlled by stirrups
𝑉𝑅 =
1 𝑕− 𝑥
𝑚𝑖𝑛 𝑁; 0.55𝐴 𝑐 𝑓𝑐 + 1 − 0.05𝑚𝑖𝑛 5; 𝜇∆𝑝𝑙
𝛾 𝑒𝑙 2𝐿 𝑣
∙ 0.16𝑚𝑎𝑥 0.5; 100𝜌 𝑡𝑜𝑡
1 − 0.16𝑚𝑖𝑛 5;
𝐿𝑣
𝑕
𝑓𝑐 𝐴 𝑐 + 𝑉 𝑤
Shear resistance as controlled
by web crushing (diagonal
EN1998-3,cl.A.3.3.1(2&3)
See below:
compression)
Before flexural yielding (𝜇∆𝑝𝑙 = 0), or after flexural yielding (cyclic 𝜇∆𝑝𝑙 > 0)
Walls
𝑉 𝑅,𝑚𝑎𝑥 =
0.85 1 − 0.06𝑚𝑖𝑛 5; 𝜇∆𝑝𝑙
𝛾 𝑒𝑙
1 + 1.8𝑚𝑖𝑛 0.15;
+ 0.25𝑚𝑎𝑥 1.75; 100𝜌 𝑡𝑜𝑡
Columns
𝑁
𝐴 𝑐 𝑓𝑐
1 − 0.2𝑚𝑖𝑛 2;
𝐿𝑣
𝑕
1
𝑓𝑐 𝑏 𝑤 𝑧
Lv / h ≤ 2 after flexural yielding (cyclic 𝜇∆𝑝𝑙 > 0
Valentinos Neophytou BEng (Hons), MSc
Page 55 of 61

56. Design notes for Seismic Assessment to Eurocode 8 - Part 3
𝑉 𝑅,𝑚𝑎𝑥 =
4/7 1 − 0.02𝑚𝑖𝑛 5; 𝜇∆𝑝𝑙
𝛾 𝑒𝑙
1 + 0.45 100𝜌 𝑡𝑜𝑡
𝑚𝑖𝑛 40; 𝑓𝑐 𝑏 𝑤 𝑧 𝑠𝑖𝑛2𝛿
where:
𝑡𝑎𝑛𝛿 = 𝑕/2𝐿 𝑣
Beam column joint
Requirements
Values
𝛾 𝑅𝑑 = 1.2
Overstrength factor
Shear force acting of the
joint
Interior
joint
Exterior
joint
References
EN1998-11,cl.5.5.2.3(2)
𝑉𝑗 𝑕𝑑 = 𝛾 𝑅𝑑 𝐴 𝑠1 + 𝐴 𝑠2 𝑓 𝑦𝑑 − 𝑉 𝐶
𝑉𝑗 𝑕𝑑 = 𝛾 𝑅𝑑 𝐴 𝑠1 𝑓 𝑦𝑑 − 𝑉 𝐶
𝑉𝑗 𝑕𝑑 = 𝜂𝑓𝑐𝑑 1 −
Shear capacity of joint
𝑣𝑑
𝑏 𝑕
𝜂 𝑗 𝑗𝑐
Where
𝑓𝑐𝑘
250
See above (NC)
EN1998-11,cl.5.5.2.3(2)
EN1998-11,cl.5.5.3.3(2)
𝜂 = 0.6 1 −
Shear strength
Valentinos Neophytou BEng (Hons), MSc
EN19983,cl.A.3.3.1(1)
Page 56 of 61

57. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Limit State of Significant Damage (SD)
Requirements
Values
References
𝜃 𝑢𝑚 = 𝜃 𝑢𝑚 ∙
Chord rotation capacity
3
4
EN19983,cl.A.3.2.3(1)
Shear strength (Beams & Columns)
The verification against the exceedance of these two LS is not required, unless these two LS are the
only ones to be checked. In that case NC requirements applies.
Beam column joint
Requirements
Values
References
The verification against the exceedance of these two limit state SD and DL is not required, unless
these two LS are only ones to be checked. In that case NC requirements applies.
Limit State of Damage Limitation (DL)
Requirements
Values
References
Design shear resistance (EC2)
𝑣 𝑚𝑖𝑛 = 0.035𝑘 3/2 𝑓𝑐𝑘 0.5
Value of vmin
Design compressive
Compressive stress in the
𝜍 𝑐𝑝 =
concrete from axial load
Reinforcement ratio for
𝜌𝐼 =
longitudinal reinforcement
EN1992-1-1,cl.3.1.6(1)
𝑁 𝐸𝑑
≤ 0.2𝑓𝑐𝑑
𝐴𝑐
EN1992-1-1,cl.6.2.2(1)
𝐴 𝑠𝑖
𝑏𝑤 𝑑
≤ 0.02
EN1992-1-1,cl.6.2.2(1)
𝑘1 = 0.44
Coefficient factor k1
𝑘 = 1+
Coefficient factor k
Shear
𝑓𝑐𝑘
𝛾𝐶
𝑓𝑐𝑑 =
strength
𝑉 𝑅𝑑,𝑐 =
EN1992-1-1,cl.5.5(4)
200
≤ 2,0
𝑑
𝐶 𝑅𝑑 ,𝑐 𝑘 100𝜌 𝐼 𝑓𝑐𝑘
Valentinos Neophytou BEng (Hons), MSc
EN1992-1-1,cl.6.2.2(1)
1.3
EN1992-1-1,cl.6.2.2(1)
+ 𝑘1 𝜍 𝑐𝑝
EN1992-1-1,cl.6.2.2(1)
Page 57 of 61

58. Design notes for Seismic Assessment to Eurocode 8 - Part 3
𝑉 𝑅𝑑,𝑐𝑚𝑖𝑛 = 𝑣 𝑚𝑖𝑛 + 𝑘1 𝜍 𝑐𝑝 𝑏 𝑤 𝑑
𝑎𝑣 = 1
when
My > LvVRd.c
𝑎𝑣 = 0
Tension shift, αv
when
My < LvVRd.c
Chord rotation
𝑧 = 𝑑 − 𝑑‫׳‬
𝑧 ≈ 0.95𝑑
𝑧 = 0.8𝑕
Lever arm, z
-
Lever arm, z
(for rectangular wall
section)
𝜀𝑦 =
Strain , εy
𝜃𝑦 = 𝜑𝑦
𝑓𝑦
𝐸𝑠
EN1998-3,cl.A.3.2.4(2)
𝜀 𝑦 𝑑 𝑏𝐿 𝑓𝑦
𝐿𝑣 + 𝑎𝑣 𝑧
𝑕
+ 0.0014 1 + 1.5
+
3
𝐿𝑣
𝑑 − 𝑑‫𝑐𝑓 6 ׳‬
Note:
Beams/Columns
𝜀𝑦 = 𝜀𝑦
𝑙𝑜
𝑙 𝑜𝑦 ,𝑚𝑖𝑛
for 𝑙 𝑜 < 𝑙 𝑜𝑦 ,𝑚𝑖𝑛
and
𝑀𝑦 = 𝑀𝑦
𝜃𝑦 = 𝜑𝑦
𝑙𝑜
𝑙 𝑜𝑦 ,𝑚𝑖𝑛
for 𝑙 𝑜 < 𝑙 𝑜𝑦 ,𝑚𝑖𝑛
𝜀 𝑦 𝑑 𝑏𝐿 𝑓𝑦
𝐿𝑣 + 𝑎𝑣 𝑧
+ 0.0013 +
3
𝑑 − 𝑑‫𝑐𝑓 6 ׳‬
Note:
Walls of rectangular, T or
𝜀𝑦 = 𝜀𝑦
barbelled section
𝑙𝑜
𝑙 𝑜𝑦 ,𝑚𝑖𝑛
for 𝑙 𝑜 < 𝑙 𝑜𝑦 ,𝑚𝑖𝑛
and
𝑀𝑦 = 𝑀𝑦
𝑙𝑜
𝑙 𝑜𝑦 ,𝑚𝑖𝑛
for 𝑙 𝑜 < 𝑙 𝑜𝑦 ,𝑚𝑖𝑛
Alternative expressions
Beams
𝜃𝑦 = 𝜑𝑦
Columns
Valentinos Neophytou BEng (Hons), MSc
𝑑 𝑏𝐿 𝑓𝑦
𝐿𝑣 + 𝑎𝑣 𝑧
𝑕
+ 0.0014 1 + 1.5
+ 𝜑𝑦
3
𝐿𝑣
8 𝑓𝑐
Note:
Page 58 of 61

59. Design notes for Seismic Assessment to Eurocode 8 - Part 3
𝑀𝑦 = 𝑀𝑦
𝜃𝑦 = 𝜑𝑦
Walls of rectangular, T or
𝑙𝑜
𝑙 𝑜𝑦 ,𝑚𝑖𝑛
for 𝑙 𝑜 < 𝑙 𝑜𝑦 ,𝑚𝑖𝑛
𝑑 𝑏𝐿 𝑓𝑦
𝐿𝑣 + 𝑎𝑣 𝑧
+ 0.0013 + 𝜑 𝑦
3
8 𝑓𝑐
Note:
barbelled section
𝑀𝑦 = 𝑀𝑦
𝑙𝑜
𝑙 𝑜𝑦 ,𝑚𝑖𝑛
for 𝑙 𝑜 < 𝑙 𝑜𝑦 ,𝑚𝑖𝑛
Requirements for lamping zone of longitudinal bars
Actual lamping ratio (at the
𝜌 = 2𝜌
Lap length
Minimum length of lap
EN1998-3,cl.A.3.2.4(3)
𝑙 𝑜 ≥ 15𝑑 𝑏𝐿
zone of overlapping)
EN1998-3,cl.A.3.2.4(4)
𝑙 𝑜𝑦 ,𝑚𝑖𝑛 = 0.3𝑑 𝑏𝐿
𝑓 𝑦𝐿
𝑓𝑐
splice for existing concrete
members
EN1998-3,cl.A.3.2.4(3)
fc and fyL are derived from the mean
values multiplied by the CF
Shear strength
The verification against the exceedance of these two LS is not required, unless these two LS are the
only ones to be checked. In that case NC requirements applies.
Beam column joint
Requirements
Values
References
The verification against the exceedance of these two limit state SD and DL is not required, unless
these two LS are only ones to be checked. In that case NC requirements applies.
Valentinos Neophytou BEng (Hons), MSc
Page 59 of 61

60. Design notes for Seismic Assessment to Eurocode 8 - Part 3
Summary table
Limit State (LS)
Member
Damage Limitation
Significant damage
Near Collapse
(DL)
(SD)
(NC)
𝜃 𝑠𝑑 ≤ 0.75𝜃 𝑢 ,𝑚 −𝜍
𝜃 𝑠𝑑 ≤ 𝜃 𝑢,𝑚 −𝜍
𝜃 𝑠𝑑 ≤ 0.75𝜃 𝑢𝑚
𝜃 𝑠𝑑 ≤ 𝜃 𝑢𝑚
Ductile primary
(flexural)
Ductile secondary
𝜃 𝑠𝑑 ≤ 𝜃 𝑦
(flexural)
(shear)
𝑉 𝐸,𝐶𝐷 ≤ 𝑉 𝑅𝑑.𝐸𝐶2 𝑎𝑛𝑑 𝑉 𝐸,𝐶𝐷 ≤
𝑉 𝑅𝑑 ,𝐸𝐶8
; 𝐽𝑜𝑖𝑛𝑡: 𝑉 𝐶𝐷 ≤ 𝑉 𝑅𝑑𝑗𝐸𝐶 8
1.15
𝑉 𝐸,𝐶𝐷 ≤ 𝑉 𝑅𝑑.𝐸𝐶2 𝑎𝑛𝑑 𝑉 𝐸,𝐶𝐷 ≤
Brittle primary
𝑉 𝑅𝑑 ,𝐸𝐶8
; 𝐽𝑜𝑖𝑛𝑡: 𝑉 𝐶𝐷 ≤ 𝑉 𝑅𝑑𝑗𝐸𝐶 8
1.15
Brittle secondary
(Shear)
θE, VE: chord-rotation & shear force demand from analysis;
VE,CD : from capacity design; θy: chord-rotation at yielding
θum: expected value of ultimate chord rotation under cyclic loading, calculated using mean
strengths for old materials divided by the confidence factor and nominal strengths for new
materials.
θu,m-σ: mean-minus-sigma ult. chord rotation =θum /1.5, or =θy+θplum/1.8
VRd, VRm: shear resistance, w/ or w/o material safety & confidence factor
VR,EC8: shear resistance in cyclic loading after flex. yielding
Valentinos Neophytou BEng (Hons), MSc
Page 60 of 61

61. Design notes for Seismic Assessment to Eurocode 8 - Part 3
GENERAL CONSEQUENCE OF USE EUROCODE 8-PART 3
1.
PERFORMANCE
REQUIREMENT
&
CRITERIA
2.
APPLICABILITY
CONDITIONS OF THE
FOUR ANALYSIS
METHODS
3.
TYPE OF VERIFICATIONS
FOR DUCTILE AND
BRITTLE MODES OF
BEHAVIOUR AND
FAILURE
4.
COLLECTION OF
INFORMATION FOR THE
ASSESSMENT AND ITS
IMPLICATIONS
5a.
CONCRETE
STRUCTURES
5b.
STEEL OR COMPOSITE
STRUCTURES
Valentinos Neophytou BEng (Hons), MSc
5c.
MASONRY BUILDINGS
Page 61 of 61