Project 1

PROJECT 1

1Q. There are 200 2BHK apartments and 100 3BHK apartments in a residential society. A normal family resides in a 2BHK apartment with three people, and a 3BHK apartment with four people. The total amount of water used for each of the activities listed below can be used to compute the gross water demand (per person, per day, in liters).

Activities
1. Utilization = (per individual/day in liters)

2. Drinking = 5

3. Cooking = 45

4. Bathing = 30

5. Flushing the toilet = 25

6. Washing Clothes = 35

7. Other uses = 10

The residential society has 1000 total residents, according to the statistics provided.

150 liters of water are used daily by one person.

150000 liters of water are used daily in residential communities.

Limits & Site Information:

Since this is the best place for an underground water tank in the event of a fire, one of the underground water tank's size is restricted by the width of the internal road in the residential community. Since the width of the road is 6 meters, the breadth of the tank cannot be wider than 6 meters.
The table below shows the soil's bearing capacity at various founding depths.

Founding Depth (Below F.G.L)	S.B.C (Tonnes/sqm)
-3.00 m LVL	7.5
-4.00 m LVL	8
-5.00 M LVL	8.5

Take into account a 25 mm permitted soil settlement beneath the foundation slab.

The top cover slab has a maximum one-way direction span of four meters and a thickness of 500mm. If the top slab span is greater than 4 meters, use a structural beam with dimensions of 500 by 900 (minimum concrete grade M25) to break the span. It should be noted that the current problem statement does not require the design of the beam or the top slab.

Loadings:

The maximum superimposed dead load for the top cover slab is 3 kN/m2, and the maximum live load that should be considered is 15 kN/m2.

Think about the weight of water in units of 10 kNm3 and soil in units of 18 kN/m3. It is necessary to take into account the soil's saturation level.

Make a full-scaled 3D STAAD pro model of the subterranean water tank that complies with the site's limitations, the estimated demand, and the FEA best practice recommendations.

All relevant loadings on the structure, support conditions, material specifications, and an average mesh size of 500 mm should be included in the final model. The center line technique will be used to model all of the geometry, and the model must be error- and warning-free.

Solution:

Unit weight of materials according to the code

18 kN/m^3 is the safe bearing capacity.

Concrete with plain cement = 24 kN/m^3

Concrete with reinforced cement = 25 kN/m^3

Concrete screed with cement = 20 kN/m^3

Masonry made of cement = 22kN/m63

Steel for structure = 78.5 kN/m^3.

Building loads

3.75kN/m^2(0.15mx25kN/m^3) is the slab weight.

Divisions equal 1.5 kN/m^2.

Finish floor: 2.5 kN/m^2

For Others, the value is 1kN/m^2.

Floor load total = 8.75kN/m^2

Weights of slab units

3.75kN/m^2(0.15mx25kN/m^3) is the slab weight.

Waterproofing and insulations = 0.5 kN/m^2.

Services for MEP = 0.5kN/m^2

Others equals 0.5kN/m^2.

Roof load total = 5.25 kN/m^2

Shared corridor: 3 kN/m^2.

Floor load total = 3kN/m^2

Roof accessibility = 1.5 kN/m^2

Roof load total = 1.5 kN/m^2

Slab design (IS-456)

Ly = 3.125m is the span shorter direction (clear).

Longer span in a distinct direction Lx is equivalent to 5.5m.

3kN/m is the live load on the slab (LL).

Concrete's compressive strength (Fck) = 25 N/mm^2

Steel yield strength (Fy) = 415 N/mm^2

Concrete weight in units (Yc) = 25 kN/m^3

Floor finish unit weight: 100mm(Y) = 22kN/m^3

Concrete cover that is clear = 25 mm

Slab (B) of bearings = 250 mm

Step 1

L/d = 32 is the span to effective depth ratio.

Effective depth minimum (d) = 97.67 mm

Depth total (D) = 127.66 mm

Bars' diameter in the shorter direction = 10 mm

Bar diameter in the extended direction = 10 mm

120mm is the effective depth(d).

Filling the slab with load

The slab's dead load (DL) is 3.75kN/m^2.

Extremely low load = 5 kN/m^2

3kN/m^2 is the slab's live load.

The slan's total load is 11.75 kN/m^2.

Total load x load factor is the design load = 17.63kN/m^2

Span effective Lx = 3.25 m

Ly is 5.62 meters.

Lx/Ly (two-way) = 1.732

For negative moments (at the top), 1.5 Alpha x 1.75 Alpha y = 0.075 0.104683 0.107 0.084

Step - 2 for positive moments (bottom):

0.056~0.103307~0.107~0.063

BM per slab width unit Mx=αxwLx^2 My=αywLy^2
Regarding negative moments (uppermost): 19.43 ± 15.59 kN/m
For positive situations, 19.17 11.69 kN-m/m (bottom)
Shear force V equals 28.6 kN/m/0.5WLx.

Step 3

To determine the slab's effective depth= 0.138Fckbd^2 for Mu,lim
D is equal to 74.55 mm.

Step 4

slab's depth for shear force Tc,max is equal to 3.1N/mm^2.
Tc equals 0.3.
K is equal to 1.2.
D is equivalent to 200 mm.
Tc is equal to 0.3N/mm^2.

Vu/bd = Tv= 0.24 N/mm^2.

0.24<0.36<3.1 Hence Safe

Step 5

Estimating the steel's area

Mu = 0.87FyAstd(Fckbd - 1-AstFy)

For a Negative Bending moment

Mutop is 19.43 kN/m.

Ast = 561.65 mm^2/m

For a Positive Bending moment = 19.17 kN/m for Mubottom

Ast = 554.27 mm^2/m

Calculating the steel distribution

Astmin is 0.12bd = 114 square millimeters

Choosing steel reinforcement bars

Bar area (upper steel) = 78.5 mm^2

140 mm is the spacing.

125 millimeters

125mm apart, 16mm bqars should be provided.

Area of bars (78.5 mm^2) for bottom steel

Measurement of spacing: 142 mm

= 125 mm

Give 16 mm bars 125 mm apart.

Wind load calculation (IS875-Part 3)

Wind speed design Vz = Vbk1k2k3k4 m/s

Bangalore's basic wind speed is Vb = 33 m/s.

Factor of probability k1 = 1.

Ground factor k2 equals Category 4B.

Factor of topography k3 = 1.

Wind pressure design (Pz) = 0.6Vz^2

Floor	Height	K2	Vz	Pz	Pz in kN
1	3.5	0.76	25	377.40	0.38
2	7	0.76	25	377.40	0.38
3	10.5	0.76	25	377.40	0.38
4	14	0.76	25	377.40	0.38
5	17.5	0.76	25	377.40	0.38
6	21	0.76	26	397.53	0.40
R	24.5	0.76	26	461.04	0.46

Seismic Load Calculation (IS1893-Part I)

Base shear design VB = Ah x W

Whereas

Ah is the horizontal seismic coefficient, determined using 6.4.2.

W= The entire weight of the construction

Building height (h) = 24.5 m

The building's base dimension

Distance Along-X = 25 m

Along-Z is 16 meters.

T - X = 0.5513 seconds

Z - T = 0.4410sec

For difficult soil, Sa/g = 1/T = 1.814 Along X = 2.268 Parallel to Z

R = 3, the responce reduction factor

Factor of importance I = 1.2

Coefficient of horizontal acceleration Ah = 0.0363
3.6812%

seismic mass

Each level A's area is 400 m^.

Because of dead loads Floor DL on average is 12.5 kN/m2.

W DL equals 5000kN.

Because to dead loads, the roof

DL roof is equivalent to 9kN/m2.

3600kN is the W DL roof.

Live loads cause the typical floor's LL to be 3kN/m2.

W LL equals 300 kN/m^2.

Live loads cause Roof LL to equal 1.5 kN/m2.

W LL roof is equal to 0.

Seismic weight total W = 35400kN

Base shear design (VB) = AhxW = 1605.44 kN

Pictures attached below;