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"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 10:Dams and Retaining Walls"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Problem 10.19,page no.459"
]
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"input": [
"from __future__ import division\n",
"import math\n",
"#Given\n",
"#Variable declaration\n",
"h=20 #height in m\n",
"D=4 #External diameter in m\n",
"d=2 #Internal diameter in m\n",
"p=1 #Horizontal wind pressure in kN/sq.m\n",
"w=22 #specific weight in kN/m^3 \n",
"K=2/3 #Co-efficient of wind resistance\n",
"\n",
"#Calculation\n",
"A1=(math.pi/4)*(D**2-d**2) #Area of cross-section\n",
"W=w*A1*h #Weigth of the chimney in kN\n",
"sigma0=W/A1 #Direct stress in kN/sq.mm\n",
"A2=D*h #Projected area of the surface exposed to wind in sq.m\n",
"F=K*p*A2 #Wind Force in kN\n",
"M=F*h/2 #Bending moment in kNm\n",
"I=(math.pi/64)*(D**4-d**4) #Moment of inertia\n",
"y=D/2 #Distance between C.G. of the base section and extreme edge of the base\n",
"Z=I/y #Section modulus\n",
"sigmab=M/Z #Bending stress \n",
"sigma_max=round(sigma0+sigmab,2) #Maximum stress in kN/sq.m\n",
"sigma_min=round(sigma0-sigmab,2) #Minimum stress in kN/sq.m\n",
"\n",
"#Result\n",
"print\"Maximum stress =\",sigma_max,\"kN/m^2\"\n",
"print\"Minimum stress =\",sigma_min,\"kN/m^2\"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Maximum stress = 530.54 kN/m^2\n",
"Minimum stress = 349.46 kN/m^2\n"
]
}
],
"prompt_number": 3
},
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"input": [],
"language": "python",
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