3D-Dynamic design for reinforced versus prestress concrete - PowerPoint Presentation

Slide1

3D-Dynamic design for reinforced versus prestress concrete for Al-Huriya building

Prepared by

Nizar Abed Al-Majeed Salameh

Mohamed Khaled Abu-Al Huda

Supervisor

Dr. Imad Al-QasemSlide2

CHAPTER ONEINTROUCTIONThe project is a structural analysis and 3D-Dynamic design of an office building in Ramallah city, known as AL-Huriya, which consists of a seven stories, with 3.5 height except the first floor with 4m story height.

The building will be first designed under a static load, after that we will study the building for dynamic , finally a prestress concrete will be used to design the building to compare it with the reinforcement concrete, to conclude many factors that should be taken into consideration in designing any structure. These include economic factors , durability and the safety of its inhabitants.Slide3

System

Part

F’c

fy

Reinforced

Concrete

Slab

250 kg/cm24200 kg/cm2Beams250 kg/cm24200 kg/cm2Columns500 kg/cm24200 kg/cm2Footings250 , 500 kg/cm24200 kg’cm2Prestress Concreteslab6000Psi243KsiColumns500 kg/cm24200 kg/cm2Footings250 , 500 kg/cm24200 kg/cm2

Materials

Live load0.4ton/m2Super imposed load0.3ton/m2

LoadsSlide4

CHAPTER TWO

SLAB Slide5

One way solid slab is used only as slab systemUse slab thickness of 17cm , according to deflection requirement

In design phase of the slab, there are two strip(1m) taken as a

model.

W

u

=1.51

15@3.75m

6@3.75mWu=1.51Strip IStrip IILoads distribution Slide6

Strip I

Use 4Ф12mm for negative and positive moment

Moment distribution

Strip IISlide7

CHAPTER THREEBEAMSBeams in this part of the project will be designed using reactions from beam model in SAP2000

.The girder system is used to design the building, and all of the beams are dropped; multi span and large space beams are used in all floors.

The system of the building consist of a four beams group (B1, B2, B3, B4)And a two group of girders (G1, G2).Slide8
Slide9

Design for Moment

Final Results

Positive Moment

Negative Moment

Exterior spans

Interior span

Interior supports

BeamsDimensionsMnΡAsMnρAsMnρAsB130x8065.610.010225.451.310.00337.6258.760.009122.90B250x90168.82

0.0112

58.883.440.003314.70152.170.011349.06

B3

50x90

183.76

0.0141

63.78

-

-

-

129.34

0.0094

44.16

B4

60x100

263.26

0.0133

78.50

-

-

-

-

-

-

Final Results

Positive Moment

Negative Moment

Exterior spans

1st interior spans

2nd interior spans

1st interior supports

2nd interior supports

GirdersDimensionsMnρAsMnρAsMnρAsMnρAsMnρAsG150x90164.240.012353.9751.99.003619.63117.93.008539.25163.620.012353.97141.80.010440.06G290x100384.780.0129112.54219.22.006964.3162.57.003332.15411.270.0141120.58209.440.006656.27

Moment Design

Parameter

Dimensions

Mn

As

Vn

Vc

Vs

Av

S

Units

cm

ton.m

cm

2

ton

ton

ton

cm

2

cmSlide10

Shear DesignDesign for Shear

Final Results

Exterior spans

Interior span

Beams

Dimensions

Vn

VcVsAvSVnVcVsAvSB130x8031.74618.85512.8901.573521.25018.8552.3951.5735B250x9080.1035.6144.493.14255435.6118.393.1440B3

50x90

77.2235.6141.613.142525.1035.6114.8753.14

40

B4

60x100

69.69

47.76

21.43

3.14

45

-

-

-

-

-

Final Results

Exterior spans

1

st

interior spans

2

nd

interior span

Girders

Dimensions

Vn

Vc

Vs

Av

S

Vn

VcVsAvSVnVcVsAvSG150x9093.4935.6157.883.142075.4435.6139.833.142592.2635.6156.653.1420G290x100229.171.64157.43.145202.671.641313.14599.5271.6427.883.1445Slide11

Final Results

For positive moment (span)

Negative moment (support)

Beam

Exterior

1

st

interior2nd interior1st interior2nd interiorB110Φ183Φ18-9Φ18-B212Φ253Φ25-10Φ25-B313Φ25--9Φ25-B416Φ25----G111Φ254Φ258Φ2511Φ25

10Φ25

G214Φ328Φ324Φ3215Φ327Φ32Slide12

CHAPTER FOURCOLUMNSsixteen columns having a rectangular section, and

eight columns having a circular section, will be designed.

All the columns in this project are classified into two groups depending on the ultimate axial load and the shape.

The ultimate axial load on each column is from the Reaction of beams

Columns number

Ultimate load(ton)

Ultimate loads from seven stories(ton)

C1144.241009.68C260.96426.72C3179.181254.26C4452.713168.97C5287.652013.55Group (1)C1,C2,C3RectangularGroup (2)C4,C5Circular Slide13
Slide14

Summary of result

Group

Pu

(ton)

Dimensions(h*b)(cm) spirally (D)(cm)

ρ

As(cm2)

# of barsShear reinforcementI1254.26100*500.015276.0416 Φ25mm4 Φ10mm/30cmII3168.97Spiral, D=1000.0206267.4134 Φ32mmΦ10mm(spirally)Final ResultsSlide15

CHAPTER FIVEFOOTING In this chapter the footing will be designed, all footings in this part of the project will be isolated (single) footings.

The design will depend on the total axial load carried by each column.

Group

ID

Columns

included

Loads (ton)

Dead loadLive loadF1C1,C2,C3726203F2C4,C51698504The footings are classified into two groups Slide16
Slide17

Flexure Design  

X-Y Direction Steel Design  

Mu =

107.12

ton.m

ρ =0.0023 As =25.62cm2As min =21.6cm2  Use As = 25.62cm2  Bar Diameter25mm  # of Bars Needed6

  Spacing16.67cmGroup F1 Design

Use

Main Steel

6ф25/ m

Or

1ф25/16cm

Shrinkage Steel

5ф25/20cmSlide18

Flexure Design  

X-Y Direction Steel Design  

Mu =

274.80

ton.m

ρ =0.0025 As =43.24cm2As min =32.4cm2  Use As = 43.24cm2  Bar Diameter32mm  # of Bars Needed6

  Spacing16.67cmGroup F2 Design

Use

Main Steel

6ф32/ m

Or

1ф32/16cm

Shrinkage Steel

5ф32/20cmSlide19

FootingID

Footing Dimentions

(m)

Bottom Steel

Top Steel

Width

Length

ThicknessLong dir.Short dir.Long dir.Short dir.F14.65.11.26ф25/ m6ф25/ m3ф25/20cm3ф25/20cmF27.457.451.86ф32/ m 6ф32/ m 3ф32/20cm3ф32/20cmFinal ResultsSlide20

Ground Beam DesignSlide21

Dimensions

Bottom & Top Steel

G.BWidth(m)

Depth(m)

exterior

interior

Support

G.B I0.40.77Ф205ф187Ф25G.B II0.50.759Ф255ф1810ф25Final ResultSlide22

Static vs. Dynamic analysis

Our representative element will be the bending moment at the mid span of the interior span in the 2nd frame for each model.

We will take model for three stories , seven stories

and ten

stories then read the moment due to dead load and live load.

Moment due

Three Stories

Seven StoriesTen StoriesAverageLive Load9.79.529.729.549.829.66Dead Load25.3824.9325.4624.9925.7725.31As the result shows, the common practice is correct for interior floors in static analysisStatic analysisSlide23

Columns ComparisonOur representative element will be the axial force due to

live load .

We will take model for three stories , seven stories and ten stories

,then

read

the axial force for corner , edge and interior columns in the bottom of each model.

SAP 2000 Analysis Results

Axial Force ForThree StoriesSeven StoriesTen StoriesCorner Column43.32 ton105.98 ton157.76 tonEdge Column86.68 ton207.98 ton302.27 tonInterior Column241.98 ton485.37 ton676.77 tonSlide24

Internal Col.

Edge Col.

Corner Col.

Tributary

areaSlide25

Tributary area ResultsLive Load = 0.4 ton/m2

Axial Force ForThree Stories

Seven StoriesTen StoriesCorner Column

43.03 ton

100.41 ton

143.44 ton

Edge Column

93.66 ton218.53 ton312.19 tonInterior Column187.31 ton 437.06 ton624.38 tonSlide26

Using SAP 2000 Software

# of StoriesT(sec)Mass Participation Ratio

DirectionOne

0.534228

0.995042

X-Direction

0.435512

0.996652Y-DirectionThree1.0991290.965566X-Direction0.8824230.970756Y-DirectionSeven2.0924260.932716X-Direction1.657030.938386Y-DirectionTen2.8069960.913832X-Direction2.214390.91895Y-DirectionSeven+Elcento2.0924260.932716X-Direction1.657090.938386Y-DirectionDynamic AnalysisSlide27

CHAPTER SEVENPRESTRESS CONCRETEPrestress concrete is not a new concept, it’s backing to 1872. (Jackson), an engineer from California, patented

prestressing system that used a tie rod to construct beams or arches from individual blocks.

The most practical development in prestressed concrete occurred from (1920 – 1960).

Introduction

We will design the

prestress

building for gravity loads only, and the punching shear excluded from this study.(ACI units is used)Slide28

Material properties and loadsMaterial properties:-f’c

=6000 Psi f’ci

= 4200 Psffp

u

= 270

Ksi

fpy =243 Ksifpe= 159 Ksi fy = 60000 PsiUse strands = 1.0 inch. Pe= 257597 IbLoads:-live load (LL) = 80 PsfSuper Imposed Load (SID) = 60 PsfSlide29

Slab thickness = Slab thickness =

= 13.13 inches.

Take slab thickness = 13.5 inches.Slide30

 Check stresses:-1) check allowable stresses for the prestressing force and the slab own weight.

2) Check the ultimate strength .Slab Design for

prestress system Slide31

Columns design for Prestress system

Sixteen columns having a rectangular section, and eight columns having a circular section, will be designed.

All the columns in this project are classified into two groups depending on the ultimate axial load and the shape.

The ultimate axial load on each column is from the

Tributary area.

Columns number

Ultimate loads from seven stories(ton)C1606.06C21119.30C31210.70C41725.00C52240.00Group (1)C1,C2,C3Group (2)C4,C5sSlide32

Summary of result

Group

Dimensions(h*b)(cm) spirally (D)(cm)

ρ

As(cm2)

# of bars

Shear reinforcement

I95*550.012328.168 Φ22mm4 Φ10mm/25cmIISpiral, D=900.01423

128.68

16 Φ32mmΦ10mm(spirally)

Final ResultsSlide33

Footing design for prestress system

All footings in this part of the project will be isolated (single) footings.

The design will depend on the total axial load carried by each column.

The footings are classified into two groups

Group

ID

Columns

includedLoads (ton)Dead loadLive loadF1C1,C2,C3694236F2C4,C5

1284

437Slide34

Group F1 DesignFlexure Design  

X-Y Direction Steel Design  

Mu =

108.34

ton.m

ρ =0.0020 As =24.34cm2

As min =

23.4cm2

Use As =

24.34

cm

2

Bar Diameter

25

mm

# of Bars Needed

5

Spacing

20

cm

Use

Main Steel

5ф25/ m

Or

1ф25/20cm

Shrinkage Steel

5ф25/20CmSlide35

Group F2 DesignFlexure Design  

X-Y Direction Steel Design  

Mu =

222.97

ton.m

ρ =0.0031 As =42.71cm2As min =27cm2  Use As = 42.71cm2  Bar Diameter28mm  # of Bars Needed7   Spacing14.29cmUse

Main Steel

7ф28/ mOr

1ф28/14cm

Shrinkage Steel

5ф28/20cmSlide36

FootingIDFooting Dimentions

(m)

Bottom SteelTop Steel

Width

Length

Thickness

Long dir.

Short dir.Long dir.Short dir.F14.655.051.35ф25/ m5ф25/ m3ф25/20cm3ф25/20cmF26.66.61.57ф28/ m7ф28/ m3ф28/20cm3ф28/20cmFinal Results