1. Building calculations
Ole Christiansen
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2. Program: Introdution to the course
Static documentation acording to SBI 223
The load bearing system
Static analasys of Spar Nord
Groups
Projekt – Next time
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3. Exspectations ?
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4. Course contents: SBI 223, lecture 1 Vertical load, lecture 1
Horizontal load (stability of the structure), lecture 2 og 3
Wall panel design, lecture 4
Horizontal panel as a beam, lecture 5
Robustness, lecture 6
Connections between concrete element, lecture 7
Exam, repetition, lecture 12  
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5. What is a panel? Plate, forcs vertical too the surface
Panel, forces in its own plane
Exampel of a statically determinated wall structure
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6. Stability– distribution of horizontal loads
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7. Classic panel structure.
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8. Purpose with the course
Static calsulations of the structure acording to SBI 223
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9. Literature
[1] Bygningsberegninger efter EC af Bjarne Chr. Jensen og Svend Ole Hansen (Danish students)
[2] Building calculations, Bjarne Chr. Jensen og Svend Ole Hansen (Exchange students)
[3] Betonkonstruktioner efter DS/EN af Bjarne Chr. Jensen (Danish students)
EC 0,1 og 2 (Exchange students and Danish students)
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10. Exam Individuel oral exam(15-20 min)
The Exam is based on your project and the content of the course:
Vertical load (the load bearing system)
Statically determinated panels
Statically indeterminated panels
Design of a wall panel
Design of a floor panel as a beam
Connections between precasted concrete elements
Comfort - Viabrations
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11. Statisk dokumentation – BR10 og SBI223
A. Static documentation
A1. Project basis
A2. Statically analysis
A3. Structural drawings and models
A4. Structural alteration
B. Projektdokumentation
B1. Statisk projekteringsrapport
B2. Statisk kontrolrapport
B3. Statisk tilsynsrapport
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12. Could be a supplier What you have to do!
(you are the consultant engineer)
Could be a supplier
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13. Building Calculations
A typical procedure for static calculations of a structure:
Definition of the static system in the building
Loads are defined
Design the load bearing system
Design the stability of the structure
Robustness.
Comfort
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14. Static model Example: Frame structure Method – Elastic or plastic.
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15. Static models for traditionel panel structures
Panels (Skivebyggeri)
Beams and colums (Søjlebjælkebyggeri)
Plates and colums (Søjlepladebyggeri)
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16. Define the loads Seismic load –seismisk last
Imperfektion load
Reduction factor - etagereduktionsfaktor
Robustness- robusthed
combination of loads - lastkombinationer
Class of consequence – konsekvens klasse
Dead load - egenvægt
Live load - nyttelast
Wind load -vindlast
Snow load - Snelas
Accident actions- Ulykkeslast
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17. The load bearing system
How is the load transferred from the roof to the foundation?
How is the load transferred from the decks to the foundation?
Is it beams that caries the decks?
How are the beams surported?
What’s the load?
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18. Eksempel Define/chose the load bearing system in the building
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19. Vertical load - Lodret lastnedføring
Define the loads
Design the deck’s (often done by catalog)
Design the load bearing walls. (alternatively, Beams and columns)
Define the load on the roof and then go downwards
Dimension, make a guess - (tykkelse skønnes)
The wall is checked without reinforcement.
If the wall cant hold then include reinforcement.
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20. Design of load bearing wall
Suggested eccentricity for concrete structures (not included in the EC but good practice)
The eccentricity from deck’s, plate’s and beam’s is acting in the centroid of a triangle (the reacktion I assumed to be a distributed load with form as a triangle). Eccentricity (e1 and e2)
The wall above has a eccentricity (e3) and is 0,05t with a minimum of 10mm
(e4) is due to fabrications deviation. e= l/400
Eccentricity from the horizontal load, this could be internal and external wind load (e5)=Mv/N Half of the wall’s dead weight is included in N
Other rules for masonry and lightweight concrete.
Note: montage tolerance
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21. Design of load bearing wall
The resulting eccentricity in the top of the wall and in the middle:
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22. Design of load bearing wall
External wind pressure on a outer wall and the internal wind pressure is always included according to EC1 1-4 kap. 7.
2 scenarios when determining the internal wind pressure:
A dominating opening
No dominating opening
In many cases it is enough to set the wind factor to 0,2 and -0,3.
For internal walls the factor is set to 4.
Wind pressure:
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23. No reinforcement, eccentric loaded wall’s
Formel 6.6
Formel for in-situ :
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24. Facade wall’s
b) (Sandwich elements). The outer plate is not at load bearing wall an only transfers the wind load to the load bearing wall. It is allowed to included the eccentricity fro the outer plate but in many cases it is neglected. a) Traditionel wall in Denmark no eccentricity included from outer wall.
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25. Window's and door’s in wall’s
Remember : holes might increase the load between windows and doors:
Consider: how much vertical load is there between the windows and how much wind is acting on the wall between the windows?
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26. In most cases:
Internal walls: it is often enough to study the wall at the lowest level. Some times it is also necessary to study the top floors for internal wind, we might need to anchor the wall to the roof and/or the deck.
Outer walls: Have to make sure that the deadweight of the top floor and roof is enough so that the wall won't be suged out. It might be necessary to add some reinforcement between the top wall and the deck. Continue with the study on the next floor until it is okay.
See example in chapter 6, not included in [2].
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27. Sound and fire
Sound and fire can have an influence on the thickness of the wall.
Example: demand for sound (luftslydisolation) between apartments is 55 dB. To secure that this is not exceeded you need a wall with a thickness of t=180mm for concrete or t=240mm for lightweiht concrete. (1850kg/m3)
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28. Reflection?
Follow the structure in SBI-223 (It is mentioned in the Danish building regulations – Bygningsrelement)
I have uploaded an example.
The load bearing system is designed from the top and downwards.
Determinate the worst combination of the normal force and eccentricity when designing a wall for vertical load.
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29. Projektet
Groups: 4-5 in each group
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30. Static analsys – Spar Nord
Define the load bearing system in Spar Nord
Start from the top of the building and go downwards
Chose the span/direction of the roof and where are they supported
Chose the directions of the concrete floors (prefabricated elements - hollow deck)
Where do we have beams, columns and load bearing walls?
Stability- make a guess – drawings, use a marker
Which walls is a part of the stability?
Bring your suggestion too class next week.
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