Formula for short term horizontal displacement

[ak.t]

Hi All,
How to calculate the short term horizontal displacement (with adopting cracked section of the concrete) on free standing wall with eccentric footing at bottom, which is subjected to wind pressure alone. This is same as calculating torque of cantilever wall.

Thank you

 

[Lomarandil]

The majority of the deflection will be due to wall rigid rotation as the soil bearing pressures develop.

So, you need to determine a pressure/settlement relationship for your soils.

----
just call me Lo.

 

[ak.t]

Considering this as cantilever, i have calculated as follows for short-term deflection (cracked). Here, Mservice is not exceeded the cracking moment.

B = 1000 mm
D = 120mm

Ig = 1000 x 1203 / 12 = 144x10⁶ mm4

n = Es/Ec = 200000/ 26587 = 7.52
Fr = 0.62 SQRT (32) = 3.56 N/mm2
Yt = 120/2 = 60 mm

Mcr = Fr*Ig/ yt = 3.56 *144x106 / 60 = 8.544 kNm

Ma = 5.775 kNm

Ma/Mcr <1, Hence Ie = Ig



Deflection = w (uniformly distributed) *l4 / 8*E*Ig

w = 1.1 kN/m = 1.1 n/mm
loaded length = 2500 mm
total length = 3350 mm
E = 26587 n/ mm2
Ig = 144 x 10⁶ mm4

Deflection = 1.1 * 2500*2500* 2500*3350 / 8 * 26587 * 144x 106

= 1.88 mm