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Explain in detail design of staging of overhead water tank.

Mumbai University > Civil Engineering > Sem 8 > Design and Drawing of Reinforced Concrete Structure

Marks : 08

Year : DEC 2010

mumbai university ddrcs • 4.6k  views
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$V_z= K_1 \times K_2 \times K_3 \times V_b^2$

(wind speed)

$P_z=0.6V_{z^2} (\text {wind pressure } =1.5kN/m^2)$

$V_b=$ basic wind speed

$K_1=$ Risc coefficient >1 or (1 or 2)

$K_2=$ Height factor->depends on Terrain category

$K_3$=Topography=1 (for plain terrain)

Wind load calculation at each level 1)At water tank

$W_1=P_z \times\text {Height} \times\text { width of tank}$

2) At first Bracing

$W_2 =P_z$ × column width ×ht. of action ×no. of column either side

(Assume column size.)

3)At 2nd bracing:-

$W_3= P_z ×$ column width ×ht. of action ×no. of column

Calculations of moment at every joint of bracing

Moment of joint A & B

$=\dfrac P2 × \dfrac {h_1}2$

Moment at joint C & D

$=\dfrac {P+p_1}2 × \dfrac {h_2}2$

Moment at joint \EF

$=\dfrac {(P+P_1+P_2}2)× \dfrac {h_3}2$

Calculate axial force with the help of 3 basic equations at the mid point of between 2 bracing and also at the same junction of moment.

Now with the help of moments and axial force the procedure given below for the design of each brace.

Calculate $\dfrac {P_u}{fck ld} , \dfrac {M_u}{fck ld^2 }$

With the help of Pu-Mu interaction curve,

Evaluate $\dfrac {P_t}{fck}$ value which will provide us the percentage steel.

Use the formula $pt.=\dfrac {100×Asc}{bd}$

∴Evaluate Asc (Area of steel in and decide the concrete)

Spacing = $\dfrac {1000×Asv}{Asc}$

Repeat the procedure for all the bracing.

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