Structural Analysis Graduation Project

Al Baker 1 Tower

Introduction Building innformations. Location: Doha ,Qatar Consists of : 2 Basements 1 Gf 50 Stories ( 5 different plans) 2 Penthouses 1 roof Total Height : 205.5 m Land area : 90x50 m

Material properities

Concrete Fcu = 80 (Rc columns) 50 (Slabs , Composite columns and rafts ) E = 4400 N/mm2

Steel Fy=400 Mpa (Rebars) 360 Mpa (steel sections) E=2100 t/cm2

Systems and MembersGravity load resisting system SlabsStatical syatem : Flat slabs , t= 30cm (Typical floors ) t= 35 cm (Basements and Ground floor) t= 50 cm (Transfer floors)

Systems and MembersGravity load resisting systemReduced Slabs Maximum span =8 m (cantleaver) Statical system used : Flat slab , t= 30 cm Posts are planted at the edge of the slab. No change in the Architectural design .

Systems and MembersGravity load resisting systemTransfer slab

Statical system : Flat slab , t= 50 cm Results and contours

Additional X _Bottom Additional Y _bottom Additional X _Top

Staged Construction study

Staged Construction study

Comparison between Different stages values

Value Stage2 Stage3 Stage 4

Deflection mm

3.183 3.682 4.153

M11 KN.m

114 153 190

M22 KN.m

25 50 72

Staged Construction study Deflection Contours Linear Non Linear

Staged Construction study M11 Contours Linear Non Linear

Staged Construction study M11 Contours Linear Non Linear

Staged Construction study

Comparison between Linear and nonlinear analysis

Value Linear analysis

Non linear analysis

Δ %

Deflection mm

2.995 4.153 1.158 38.6

M11 KN.m

155 190 35 22.5

M22 KN.m

51 72 21 41.1

Systems and MembersGravity load resisting systemColumns Steps of design 1. Approximate calculations of base reactions by multiplying the

reaction of the slab model by the number of repeated slab 2. Ultimate loads

Systems and MembersGravity load resisting systemColumns By designing concrete columns , applied loads needs very big

sections for the edge columns. Composite columns (Concrete filled) are designed using working

loads Column Total working force ton A cm B cm a cm b cm Capacity ton

1 2199 160 50 154 44 27082 3688.5 150 70 142 64 39303 3558 150 70 142 64 39304 2320.5 150 50 144 44 25515 2205 150 50 144 44 25516 3553.5 150 70 142 64 39307 3567 150 70 142 64 39308 2232 160 50 154 44 27089 3428 150 143 3653

10 3894 160 153 390011 4212 160 152 4450

Systems and MembersGravity load resisting systemColumnsPrecautions and details for the composite columns Connection with the slab rebars

Shear studs and brackets

Fire protection

Foundation Connection and base plate (units in mm)

Systems and MembersLateral load resisting systemLateral loads

1. Earth quake Using ECP 201 Two methods have to be performed for assigning the loads Equivalent Static Method Multi Modal Response Spectrum

Systems and MembersLateral load resisting systemEqrthquakes Steps 1. Detecting the design response spectrum curve of the zone and the

soil type of the building.Building characteristics Zone : C (ag=0.15*g=1.47 m/sec2)Soil : B (TB=0.05, TC=0.25, TD=1.2, S=1.35)Importance factor γ1 =1R :5

Systems and MembersGravity load resisting system Eqrthquakes

Systems and MembersLateral load resisting system Calculating total weight of the building W= 60,700 ton

Using Dead load +ψ *L.L Where ψ = 0.5 (Normal Building)

Correction Factor (λ) = 1 (T1>2*Tc) Sd(T) = 0.2943 m/sec2 (from the response spectrum curve )

Fb Equivalent static = Sd(T)* λ*W/g= 1,822 ton Fb/W = 3% Within the Limit of ( 3-7)%

Destributing the forces on the floors using the linear approximation of the displacement

Fi=

Systems and MembersLateral load resisting systemSystems Two systems have been modeled 1st we choose core thickness 0.8 m Results from two methods Fb EQ Static =1822 tonFb R.S X=1826 tonFb R.S Y = 206 tonFb R.S /Fb Eq =100.2% >85%

T=9sec

Systems and MembersLateral load resisting system

1st system Behavior

Drift_Max Displacement _Max

Value=0.02 >0.009 Unsafe Value=3.5 m

Systems and MembersLateral load resisting system2nd system Results from two methods Fb EQ Static =1822 tonFb R.S X=1865 tonFb R.S Y = 2140 tonFb R.S /Fb Eq =102% >85%

T=7.7 sec

Systems and MembersLateral load resisting system2nd system BehaviourDrift_Max Displacement_MaxValue = 0.016 >0.009 Unsafe Value=2.5 m

Systems and MembersLateral load resisting system Straining actions

Load Combination

System P (ton) Mx (t.m) My (t.m)

EQx Max 1st system 13415 52073 65192nd system 63786 83954 120840

EQx Min 1st system 49943 21362 70552nd system 65217 10999 117128

EQy Max 1st system 25044 95367 36512nd system 62720 170999 47523

EQy Min 1st system 38314 64655 41882nd system 66284 98044 43812

Load Combination

System P (ton) Mx (t.m) My (t.m)

EQx Max 1st system 11322 62928 24353 2nd system 59388 96102 157355

EQx Min 1st system 48315 21917 22942 2nd system 60919 15730 152798

EQy Max 1st system 23008 116004 9519 2nd system 58166 197448 60882

EQy Min 1st system 36629 74993 8108 2nd system 62144 56325 28165

For this reason we have to concern for two sections •At the base (Max Normal force)•At the ground floor ( Max Moment )Results

At the ground Floor At the Base

Systems and MembersLateral load resisting system Design and Check

Using concentrated RFT (Φ32) By drawing interaction diagram and assigning all the load cases and combinations.

Systems and MembersLateral load resisting system Design and CheckUsing concentrated RFT (Φ25)

By drawing interaction diagram and assigning all the load cases and combinations.

Systems and MembersLateral load resisting system

Notes and Comments The two systems are unsafe in the Drift The first system capacity can not cover the applied straining actions Recommendations In order to get better behavior , other systems should be performed such as : . Steel Braced core . Outrigger at the service floor . 

Systems and MembersLateral load resisting system Wind LoadAccording to the ECP 201Structure Characteristics Ce 0.8 Location Cairoρ 1.25 Kg/m3 Surface terrain <5%V 33m/secct 1cs 1q 0.680625 KN/m2q=0.5*ρ*V2*Ct*Cs*〖10〗^(-3)by substitution in the Code equation for the wind pressure P=Ce*K*qWhere Ce =0.8 Windward and 0.5 Leeward And by taking the opposing dimension in X and Y directions maximum A=31.4mB=29.5mForce/Floor X = P*Hi*BForce/Floor Y= P*Hi*A

Systems and MembersLateral load resisting systemWind load Model and Results Total Base Shear FBX=1060 ton. Total Base Shear FBY = 1131 ton.

Systems and MembersLateral load resisting systemWind load Behavior (Drift)Drift _X Drift_ YValue Max Drift =0.00175<0.009 Safe Value Max Drift= 0.00165< 0.009 Safe

Systems and MembersLateral load resisting systemWind load BehaviorDisplacement _X Displacement_ YValue max=28 cm Value max =24 cm

Systems and MembersLateral load resisting systemWind load Straining actions

TABLE: Pier Forces          

Story Pier Load Case/Combo Location P M2 M3        kN kN-m kN-m

First Floor CORE WINDCOMBO_X Bottom -666016.8 -837401.6 1004644.8

First Floor CORE WINDCOMBO_Y Bottom -638892.8 52756.14 2493696.8

2nd Basement CORE WINDCOMBO_X Bottom -702058.4 -616497.6 838189.6

2nd Basement CORE WINDCOMBO_Y Bottom -675959.2 65811.28 2098448.8

Systems and MembersLateral load resisting systemWind loadStraining actions By assigning the loads on the interaction diagrams .The Section is Safe

Systems and MembersLateral loadColumns Check under lateral loadsCriteria of checking Composite columnsBy substitution in the interaction equation according to the ECP205  Fca/Fc+(fbx/0.72fy)*A1+(fby/0.72fy)*A2 < 1  Where Fca=Pworking/AsFc= allowable stress as in the previous clause Fbx and Fby=applied bending stress on the steel section neglecting composite action in X and Y.A1,A2 amplification factors

Systems and MembersLateral loadColumns Check under lateral loads Check is performed on the least dimension section and the largest

straining actions sections of the composite columns.

Column A B a b

1 160 50 154 44

Circular 11 160 152

Systems and MembersLateral loadColumns Check under lateral loads

ColumnLoad Combination P ton Mx t.m My t.m fca fbx fby interaction equation case

1 EQX Max 1281.43 12.93 47.14 1.04 0.225 0.4 0.541 SAFE

EQX Min 1524.29 10.29 55.71 1.245 0.179 0.46 613SAFE

EQY Max 1287.86 13.64 19.93 1.05 0.24 0.17 0.47SAFE

EQY Min 1517.86 4.79 14.64 1.24 0.08 0.122 0.465SAFE

11 EQX Max 1785.71 30.71 100.71 0.911 0.165 0.513 0.623SAFE

EQX Min 2758.57 11.14 90 1.4 0.06 0.46 0.79SAFE

EQY Max 1678.57 43.79 39.14 0.856 0.234 0.2 0.51SAFE

EQY Min 2928.57 31.57 28.79 1.5 0.17 0.15 0.76SAFE

Foundation System

System : Raft on piles Piles used Diameter = 1 m Capacity = 650 ton Stiffness = 130,000 t/m Diameter= 0.8 m Capacity = 400 ton Stiffness = 80,000 t/m

Foundation System Piles configuration Comparizon

1st 2nd 3rd

Piles used 1 m diameter 1m 0.8m 1m 0.8

No of piles 507 1064 109 229

338

Max reaction (ton) 1173 4330.5 572.3 389.1

Over all efficiency 45.17% 26.6% 55.46% 76.9 %

69.9%

Foundation

Raft Average value =250 ton

Thickness =3m Mesh 8Φ20Mur =254.3