Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001 Hong kong cop 04 rc sl 001
Trang 1Software Verification
PROGRAM NAME: SAFE
REVISION NO.: 0
EXAMPLE Hong Kong CP-04 RC-SL-001 - 1
EXAMPLE Hong Kong CP-04 RC-SL-001
Slab Flexural Design
P ROBLEM D ESCRIPTION
The purpose of this example is to verify slab flexural design in SAFE
A one-way, simple-span slab supported by walls on two opposite edges is modeled using SAFE The slab is 150 mm thick and spans 4 meters between walls To ensure one-way action, Poisson’s ratio is taken to be zero The slab is modeled using thin plate elements The walls are modeled as line supports without rotational stiffnesses and with very large vertical stiffness (1 × 1015 kN/m) The computational model uses a finite element mesh, automatically generated by SAFE The maximum element size is specified as 1.0 meter To obtain factored moments and flexural reinforcement in a design strip, one one-meter wide strip is defined in the X-direction on the slab, as shown in Figure 1
Free edge
1 m design strip Free edge
Simply supported edge at wall
4 m span
Y X
Simply supported edge at wall
Free edge
1 m design strip Free edge
Simply supported edge at wall
4 m span
Y X
Simply supported edge at wall
Figure 1 Plan View of One-Way Slab
One dead load case (DL4KPa) and one live load case (LL5KPa) with uniformly distributed surface loads of magnitudes 4 and 5 kN/m2, respectively, are defined
in the model A load combination (COMB5kPa) is defined using the Hong Kong CP-04 load combination factors, 1.4 for dead loads and 1.6 for live loads The model is analyzed for both load cases and the load combination
The slab moment on a strip of unit width is computed analytically The total factored strip moments are compared with the SAFE results After completing analysis, design is performed using the Hong Kong CP-04 code by SAFE and also by hand computation Table 1 shows the comparison of the design reinforcements computed using the two methods
Trang 2Software Verification
PROGRAM NAME: SAFE
REVISION NO.: 0
EXAMPLE Hong Kong CP-04 RC-SL-001 - 2
G EOMETRY , P ROPERTIES AND L OADING
Depth of tensile reinf d c = 25 mm
Clear span l n , l 1 = 4000 mm
Yield strength of steel f sy = 460 MPa Concrete unit weight w c = 0 N/m3 Modulus of elasticity E c = 25000 MPa Modulus of elasticity E s = 2x106 MPa
T ECHNICAL F EATURES OF SAFE T ESTED
¾ Calculation of flexural reinforcement
¾ Application of minimum flexural reinforcement
R ESULTS C OMPARISON
Table 1 shows the comparison of the SAFE total factored moments in the design strip with the moments obtained by the hand computation method Table 1 also shows the comparison of the design reinforcements
Table 1 Comparison of Design Moments and Reinforcements
Reinforcement Area (sq-cm) Load
Level Method
Moment (kN-m) A s +
Medium
,min
A+s = 162.5 sq-mm
Trang 3Software Verification
PROGRAM NAME: SAFE
REVISION NO.: 0
EXAMPLE Hong Kong CP-04 RC-SL-001 - 3
C OMPUTER F ILE : Hong KongCP-04RC-SL-001.FDB
C ONCLUSION
The SAFE results show a very close comparison with the independent results
Trang 4Software Verification
PROGRAM NAME: SAFE
REVISION NO.: 0
EXAMPLE Hong Kong CP-04 RC-SL-001 - 4
H AND C ALCULATION
The following quantities are computed for the load combination:
γm, steel = 1.15
γm, concrete = 1.50
b = 1000 mm
For the load combination, the w and M are calculated as follows:
w = (1.4w d + 1.6w t ) b
2 1
8
wl
M =
A s,min = 0.0013b w d
= 162.5 sq-mm
COMB 100
w d = 4.0 kPa
w t = 5.0 kPa
w = 13.6 kN/m
M = 27.2 kN-m
The depth of the compression block is given by:
2
bd f
M K
cu
= = 0.05803 < 0.156
The area of tensile steel reinforcement is then given by:
z d K 0.95d
9 0 25 0 5
⎠
⎞
⎜⎜
⎝
⎛
− +
z f
M A
y s
87 0
= = 584.197 sq-mm > A s,min
A s = 5.842 sq-cm