design notes
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Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
Design Notes
eng. MIHNEA Horia-Ionut
eng. VASILESCU Adrian-Eugen
08-decembrie-2014
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Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
1. Design data: The building this document reffers to has the following characteristics:
- Height: 12m
- Ground floow area: 1150 sqm
- Number of stories: 3
- Altitude: 1260 m
The loads taken into account are according to SIA 260-2003, SIA 261-2003
1.1. Loads from snow
Characteristic snow loads on level terrain:
= [1 + (0
350)
2
] 0,4 2
0 = +200 as shown in annex D from SIA 261-2003
= [1 + (1200
350)
2] 0,4 2 but greater then 0,9 kN/m
2
= 5,10
2
Exposure coefficient:
= 1,0 for normal exposure
Thermal coefficient:
= 1,0
Form Coefficient:
Taking into account the building form we have two different coeficients:
Coefficient 1: Model of charge 1 for witch 1=0,8;
Coefficient 2: Model of charge 2 for witch 1=1,6;
Depending of the roof calculated we have 2 options for the characterisc loads from snow on the structure:
,1 = 0,8 1,0 1,0 5,1
2 = 4,08
2
,2 = 1,6 1,0 1,0 5,1
2 = 8,16
2
1.2. Live loads:
The loads from live loads in 5kN/m2
for category C3 of use. The concentrated load taken into account is 4 kN.
According to paragraph 9.4. from the code we need to study the dynamic properties for the slab. In the natural period of
vibration for walking is 2 Hz and for running is between 2,4 Hz and 3.5 Hz.
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Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
1.3. Wind loads:
The global force on the building is calculated by:
=
Where:
cred is a reduction coefficient that takes into account the repartition of the forces on the surface of the building.
cd is the dynamic factor
cf is the dynamic factor
qp is the pressure
The characteristique value for wind is taken from annex E of SIA 261:
,0 = 1,1 /2
This corresponds for wind mediated at a couple of seconds interval at a height of 10m for a category III terrain.
The profile coefficient ch for categorie of terrain III for a height of the buildind of 15 m is about 1,1.
= .
The characteristic value for wind pressure: = ,0 = 1.1/2 1.1 = . /.
The reduction coefficient that takes into account the shape of the building is taken from the graph shown in figure 6 of
SIA 261. The worst case is when the wind is perpendicular on the faade.
=
=
50
14= 3.57
= .
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Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
The dynamic coefficient takes into account the dymanic properties of the structure, the natural vibration period. According
to paragraph 6.3.5. for buildings with the maximum height of 15m it takes the value of 1.
= .
The pressure coefficient is taken from annex C of SIA 261:
h:b:d=14:50:25=0.28:1:0.5
In order to calculate the structure using global forces cf=0,95 for forces normal to the faade.
= = 0.76 1.00 0.95 1.21/2
= 0,87 /2
In order to calculate the elements for the faade the characteristic pressure taken into account will be 1,83kN/mp.
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
1.4. Seismic loads:
The site placed in a zone characterized by a peak ground acceleration of 1,3 m/s2
(Zone Z3a).
The soil class taken into consideration is A (Hard rock or soft rock). For this soil type the following parameters are taken into
account: S=1,00; TB=0,15; TC=0,4; TD=2,00.
The damping ratio for a metallic structure is x=0,02.
The coefficient that corrects the spectrum is calculated with the following formula:
= 1
0,5 + 10= 1.19
With these site conditions the elastic response spectrum is as follows:
For 0TTB (1 +(2.51)
)
For TB TTC 2.5
For TC TTD 2.5
For TD T 2.5
2
For braced frames the ductility factor q=4.
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
Se(T)
Sd(T)
Td
TB
TC
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Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
2. Calculation notes
In the design model the following combinations offer the significant dimensioning values:
1,35x(Dead Loads)+1,5x(Live Loads)+1,05x(Snow Loads)+ 1,05xWind
1,35x(Dead Loads)+1,05x(Live Loads)+1,5x(Snow Loads)+ 1,05xWind
1,35x(Dead Loads)+1,05x(Live Loads)+1,05x(Snow Loads)+ 1,05xWind
As the sesismic coefficient is so small the actions induced by the earthquake is lower than the other combinations.
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
2.1. Dynamic properties:
Building modes:
Mode Period UX UY RZ
1 0.546 -0.604 35.272 -168.566
2 0.464 36.778 0.570 22.864
3 0.416 2.024 -6.326 -452.550
4 0.393 1.173 5.506 315.743
5 0.335 -0.270 -1.056 37.760
6 0.297 0.552 -0.234 2.142
7 0.292 2.785 0.801 5.287
8 0.269 -0.045 -0.461 3.835
9 0.253 2.746 1.127 -12.856
10 0.248 -3.030 0.040 -5.191
11 0.218 0.960 -0.100 3.051
12 0.214 0.557 -0.143 16.852
Modal Mass:
Mode Period UX UY SumUX SumUY RZ SumRZ
1 0.55 0.02 76.28 0.02 76.28 6.16 6.16
2 0.46 82.93 0.02 82.95 76.30 0.11 6.28
3 0.42 0.25 2.45 83.20 78.75 44.43 50.71
4 0.39 0.08 1.86 83.29 80.61 21.63 72.34
5 0.33 0.00 0.07 83.29 80.68 0.31 72.65
6 0.30 0.02 0.00 83.31 80.68 0.00 72.65
7 0.29 0.48 0.04 83.78 80.72 0.01 72.66
8 0.27 0.00 0.01 83.79 80.73 0.00 72.66
9 0.25 0.46 0.08 84.25 80.81 0.04 72.70
10 0.25 0.56 0.00 84.81 80.81 0.01 72.70
11 0.22 0.06 0.00 84.87 80.81 0.00 72.71
12 0.21 0.02 0.00 84.89 80.81 0.06 72.77
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Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
2.2. Roof Beam
2.2.1. Type 1 - HEA 800 with initial horizontal prestress of 1500kN.
Beam characteristics
A: 286 cm2
Iy: 303400 cm4
h: 790 cm
Three tendons of 4 strands with a total area of 600 mm2
were considered. The steel used for the strands has a nominal
tensile strength of 1860 N/mm2
.
Moment from pretensioning (from loads on x axis)
M0 -742.5 0
M1 -742.5 5.375
M2 -742.5 10.75
M3 -742.5 16.125
M4 -742.5 21.5
Moments from loads
p= 89.87 kN/ml
M0 0 0
M1 3894.277 5.375
M2 5192.369 10.75
M3 3894.277 16.125
M4 0 21.5
0
2000
4000
6000
0 5.375 10.75 16.125 21.5
-800
-600
-400
-200
0
0.00 5.38 10.75 16.13 21.50
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Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
Two hypothesis were considered:
1. The beam does not interact with the concrete slab;
2. The beam interacts with the concrete slab.
In both cases a sectional analysis software was used:
1. The beam does not interact with the concrete slab:
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
2. The beam interacts with the concrete slab:
As seen for a dimensioning moment of 5192 the first hypothesis does not satisfy the necessary resistance as the capacity is
of 5036 kNm. The second one shows a capacity of 7691 kNm which is much more than needed. In conclusion some elements are
needed to make the two elements to work together.
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
2.3. Column:
The worst case in from the gravitational loads:
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
As shown before in the worst case the column is at 40% of capacity.
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
2.4. Secondary beams:
The secondary beams have a dimensioning moment of 77 kNm and a capacity of 205 kNm. The beams were dimensioned
from deflection. L/300=17mm. and the effective deflection is 17mm.
-
Nr. inreg.: J/40/2760/2009
C.I.F.: 25215668
ING BANK NW Amsterdam - Bucuresti
Tel./fax: 031.428.61.06
E-mail: office@crossprojects.ro
______________________________________________________________________________________________
2.1. Largest Console (HEA 450):
The secondary beams have a dimensioning moment of 540 kNm and a capacity of 895 kNm. The beams were dimensioned
from vibration. The limit taken into consideration is 5Hz for the slab.
Eng. Mihnea Horia-Ionut
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