◦Ar-Rafedain building is 8 stories reinforced concrete building ,located in Nablus city and used as commercial and residential building.

◦The basement story is used as storage for commercial goods with plan area of 870 m², the second story is used as commercial one and the above 6 stories used as residential apartments (four apartments per floor) with plan area of 760 m².

◦soil bearing capacity = 200 kN/m2

Two way solid slab for commercial story.

One way solid slab in last story and rib slab in other residential stories.

Concrete : f’c= 320 kg/cm²( 32 MPa) for columns and shear walls. f’c= 240 kg/cm²( 24 MPa) for others. Concrete unit weight = 24.5 (KN/m3). Reinforcing Steel: The yield strength of steel is equal to 4200

Kg/cm2 (420 MPa). Others :

MaterialUnit weight(kN/m3)

Reinforced concrete25

Plain concrete23

Sand18

Aggregate17

Blocks12

Masonry stone27

Tile26

Dead loads in addition to slab own weight : Superimposed dead load = 4.5 kN/m2

Live load = 2 kN/m2 (for residential stories). Live load = 5 kN/m2 (for commercial story). Live load = 6 kN/m2 (for basement story). Water tanks load = 10 kN/m2

The following are the design codes used :1. ACI – code 2011 .2. ASCE for design loads.

• The following are the load combinations used :

1. Wu = 1.4DL.

2. Wu = 1.2DL + 1.6LL .

basement story height = 4.15m. commercial story height = 5m. residential stories height is 3.3 m.

The following are the preliminary dimensions :Slab dimensionTwo way solid slab: - depth =15 cm (based on deflection criteria) . - slab own weight = 3.68 kN/m². - Ultimate load =17.81 kN/m².

One way ribbed slab: - depth = 25 cm (based on deflection criteria) . - web width = 12 cm - slab own weight = 4.50 kN/m². - Ultimate load =14 kN/m².

beam dimension1. Main beams in x-direction : 50 cm depth x30 cm width.2. Secondary beams in y-direction : 25 cm depth x60 cm width.

column dimension Take a sample columns ( k5) : Area carried by column = 19.32 m2

Pu = 2691.79 KN. Ag = 1662 cm2.

→ Use columns 30x60cm2.

Footing : (Service load / bearing capacity) ≥ 60%

area of the building . we choose mat footing with depth of footing

100 cm .

Final dimensions : frame sections :

MemberDepth)cm(Width)cm(

Col.6035

Main beams5030

Main beams for last story5040

Secondary beams2560

Secondary beam for last story2060

Area sections dimensions :

Area section name Thickness )cm(

Two way solid Slab 15

One way ribbed Slab 25

One way solid Slab 20

Verification Of SAP model:- We perform the verification for SAP

models( one and eight stories and it was OK) the following is verification for eight stories :

- 1. Compatibility satisfied :

3.Stress -Strain relationship satisfied: Taking beam in one way ribbed 4m span : total moment hand calculation =120.82 total moment sap calculation =112.9 % error 6.9% < 10% ……..ok

Load typeHand results)KN(SAP results )KN(Error%

Dead load99923.35104714.291.6

Live load18967.5819185.341.1

2.Equilibrium Satisfied :

3. Design for bending moment :

Area of steel for one way solid slab from sap :

Span As- )mm2/m(As+

mm2

/m

Bars (Ø12mm) LeftBars

(Ø12mm)RightBars

(Ø12mm)

AB-CD600636044504

CD-EF540555053404

EF-G530549054004

G-HI550536045505

HI-J450461063604

J-K600651054004K-L M400460064504

Area of steel for one way ribbed slabs from sap :

Span As- )mm2/rib(As+mm2/rib

Bars (Ø12m

m)LeftBars

Ø12mmRightBars

Ø12mm

AB-CD280*0.52=146

211521152

CD-EF146214621152

EF-G146214621152

G-HI146214621152HI-J146216721152J-K146216721152

K-LM115214621152

Area of steel for two way solid slab from sap :*Middle strip in y direction:

*Column strip in y direction:

*Middle strip in X direction:

*column strip in X direction:

Reinforcement for beams in two way solid slab:

min reinforcement ratio = 0.0033. As min = ρbd = 0.0033*300*425 = 425 mm2

ØVc = 78.1 kN. (Av/s)min = 0.25.

shear and torsion reinforcement for edge beams and girders in two way solid slab :

Reinforcement for main beams in one way ribbed slab:

min reinforcement ratio = 0.0033. As min = ρbd = 0.0033*300*425 = 425 mm2

ØVc = 78.1 kN. (Av/s)min = 0.25.

shear and torsion reinforcement for edge beams and girders in one way ribbed slab

Reinforcement for main beams in one way solid slab:

shear and torsion reinforcement for edge beams and girders in one way solid slab

Design of secondary beams: Negative and positive area of steel for all

secondary beams = 5Ø12 mm and 1Ø8/200mm stirrups.

Column:Column grouping, Area of steel& stirrups:

Manual designPu =Øλ (0.85*f’c*(Ag+ As) + fy*As)Pu = 2691.79kN.Ag = 0.35* 0.6 = 0.21m²Ø = 0.65 λ = 0.8 f’c = 32MPaFy = 420MPaso As = 1156mm² ρ = As / Ag =1156 / 600*350 = 0.55%ρ min = 0.01 ρ max = 0.08 so use ρ min = 0.01 As = 0.01*600*350 = 2100mm² → 14Ø14 mm

Mat Footing: Bearing capacity of the soil=200 kN/m2.

thickness of mat footing:thickness of mat will be determined based on punching shear on the critical corner, edge and interior columns

Use mat thickness = 1mFor wide beam shear, ØVc = 560 kN/m and shear forces under most columns(except columns K1, K2, J2, CD6) are less than 560 kN/m → OK

Shear forces under the exceptional columns are:VK1 = 700kN/m VK2 = 1000 KN/mVJ2 = 1000 kN/m VCD6 = 1100 kN/m

but as we go far by 1m after distance d from the face of each column, shear force decreases to be less than 560kN .

So, drop panels will be used under these columns, and each one of these panel will be extended 2m from the face of the column. Depth of panels is determined as follows:

ØVc = 0.75 (1/6)√fc * bw *d Vu = 1100 kN1100 = 0.75 (1/6) √24 *d* 1000/1000 d = 1.8m → total thickness = 2.5m

reinforcement of mat footing column strip in y direction:

reinforcement of mat footing middle strip in y- direction:

reinforcement of mat footing column strip in x- direction:

reinforcement of mat footing middle strip in x- direction: