MindMap Gallery Comprehensive Bunker Design Guide
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Comprehensive Bunker Design Guide
Unlock the secrets of bunker design with our in-depth guide on structural calculations and engineering principles. This resource details the meticulous process of designing a robust and secure bunker, from initial data gathering to the intricate calculation of volume, density, and stress. Understand how to manage surcharge impacts, determine the precise volume of different structural components, and calculate sidewall pressures to ensure stability and safety. Learn the steps for designing hopper bottoms, accounting for normal pressure and corner moments, and discover the exact requirements for reinforcement steel to fortify the structure against bending moments and direct tension. Whether you're an aspiring engineer or an experienced architect, our guide provides the essential calculations and design considerations for successful bunker construction.
Edited at 2022-04-17 02:19:17
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- Outline
Bunker
step 0 : required data
= required data = 1. weight of material stored 2nd:density of material 3rd:size of c/s 4th:angle of repose 5th:grade of steel and concrete
step 1: given data in ques = of step 0
step 2: premsibble stresses
remissible stresses = sigma cbc = permissible stress in concrete in bending compression 2nd: sigma st = permissible stress in steel in tension - found out using grade of concrete and steel
step 3: dimension of bunker
volume of bunker = weight/density
dimensions of 3 parts of bunker= =(draw it in exam and label all)
surcharge = upper trianglular part
h(s)= height of surcharge
phi = angle of surcharge
middle cylindrical part = bunker
capital B = width of bunker
capital L = length of bunker
h(c) = height of central portion
hopper bottom = conical botoom
small b = bottom of hop[per bottom
small l = length of hopper bottom
depth of hopper bottom = h(h)
theta = angle of hopper bottom
step 4:volume of the three bunker parts
volume of surcharge = volume of cone = ??
volume of central portion = volume of cylinder = ??
volume of hooper bottom = strange formula= ??
new variables added in this a and A = ??
then step will be Total volume = sum of these 3 volumes
this volume should be greater than step 2 volume
step 5: design of side walls:
pressure P alpha = ??
formula of P alpha if phi = theta
assuming thickness of side walls and finding effective span (L)
thickness of side walls is asummed as=??
formula of effective span length L = ??
both have thickness in formula
Breadth = ??
design moement at support, centre of long wal, centre of short wall
formula for design moment at supports = ?? (formula for square section) (its sign)
formula for +ve moment at centre of long walls AB and CD = ??
formula for +ve moment at centre of long walls BC and AD = ??
then write a statement
Subtopic 1
direct tension in long walls = ?? , in short walls = ??
take maximum
calculation and formula of effective depth d = ??
new terms = 1st: M = maximum moment 2nd: T = maxm tension 3rd x= dist b/w centre of section and reinforcement 4th: Q = design constants =??
new terms in the 4th new term design contants : 1st: j , 2nd k , 3rd m, 4th small b assumption
formula for reinforcement in side walls = ??
formula for distribution steel
step 6: design of hopper bottom
Direct tension formula = ??
New terms = w(t) = ?? , 2nd W(hopper) formula = ?? , 3rd: assumption for theta=?
Reinforcement for direct tension Ast = ??
CHecking for mimn reinforcement formula=?
Normal components
a. normal compentn of coal pressure at centre of sloping face formula P(n) =
new term =h, formula of h = ?
b. normal component due to weight of sloping slab formula = ??
nmew term W(d) formula = ?
total normal pressure = (a)+(b)
maximum -ve bending moment
for long wall = ??
for short wall = ??
we consider maximum -ve bending moment for long walls only
new term P = ? , L = ?
after finding M, formula for reinforcement Ast = ??
maximum +ve bending moment at end formula M = ??
using this M, reinforcement Ast = ??
where is the reinforcement provided
Floating Topic
Bunker
step 1 : given data
1. W = weight of material stored 2nd: γ = density of material 3rd:size of c/s = x*x m 4th:Φ=angle of repose 5th:grade of steel and concrete
step 2: premsibble stresses
remissible stresses = σ cbc = permissible stress in concrete in bending compression 2nd: σ st = permissible stress in steel in tension - found out using grade of concrete and steel
step 3: volume of bunker and further not given dimensions
volume of bunker (V) = weight/density
v1 = volume of surcharfge = 1/3*A1*h1
calulation of h1: surcharge is like this , divide in half and make it like |\ this, hence tan Φ= h1/(base/2) = h1/triangle base == h1 = half base*tanΦ
v2 = volume of material stored in hopper bottom = 1/3*[volume of hopper - volume of central hole) = 1/3*L*B*(heigh of bottom) - 1/3*l*b*height of hole) OR: hopper bottom has another formula
volume of chmaber V3 = total volume - (volume of surchage + volume of hopper = weight of material / density of material - V1 - V2
hence height of chamber found using: volume of chamber = L*B*h3 , hence h3 =
total volume of v1+v2+v3 should be > weight amterial/density material
step 4: drawing and all dimensions
dimensions of 3 parts of bunker= =(draw it in exam and label all)
surcharge = upper trianglular part
h(s)= height of surcharge
phi = angle of surcharge
middle cylindrical part = bunker
capital B = width of bunker
capital L = length of bunker
h(c) = height of central portion
hopper bottom = conical botoom
small b = bottom of hop[per bottom
small l = length of hopper bottom
depth of hopper bottom = h(h)
theta = angle of hopper bottom
step 5: design of side walls:
horizontal presszure on side wall P(h) = γh*cosΦ*cosΦ
assuming thickness of side walls and finding effective span (L)
thickness of side walls is asummed as=180 mm
formula of effective span length L = ??
both have thickness in formula
Breadth = ??
Corner moemnt = -ve P(h)*L*L / 12
here, L used = effective length = Length + thickness of wall (280mm)
Direct tension = P(h)*L/2 =
Resultanat moment (M) = Corner moment - tension*x
this x = thickness of wall/2 - clear cover = 180/2 - 30 = 60 mm = 0.06 m
efective depth d = thickness - clear cover = 180 - 30
clear cover = 30 mm assumed
Design moment M(u) = 1.5 * Resultant moment (M)
Total area of steel required = Ast 1 + Ast 2
Area of steel required for corner moment :: M(u) = 0.87*fy*Ast*d[1 - fy.Ast / fck.b.d
this b = 1000 mm
susbtitute Mu, b, d etc and find Ast
Area of steel required to resist tenison :: Ast(T) - 1.5 T / 0.87.fy
spacing for total area of steel = π/4 * 12*!2*1000 / 1067 , using 12 mm Φ bar
bending moment at centre of span due to horizontal pressure B.M = P(H)*L*L/8 - corner moment
Resultant moment (Mu) =B.M - T*x
Total area of steel required = Ast 1 + Ast 2
Area of steel required for corner moment :: M(u) = 0.87*fy*Ast*d[1 - fy.Ast / fck.b.d
this b = 1000 mm
susbtitute Mu, b, d etc and find Ast
Area of steel required to resist tenison :: Ast(T) - 1.5 T / 0.87.fy
spacing for total area of steel = π/4 * 8*8*1000 / 216 , using 8 mm Φ bar
Distribution steel (vertical reinforcement) = 0.12% b*d = 0.12/100 *1000*180 using
step 6: design of hopper bottom
total weight = weight of coal given + self weight of hopper bottom
Self weight of hopper bottom = 4*W*cosecθ
here, Weight W = A*t*(Density of concrete) = mean width*height*thickness*(density conc)= (top width + bottom width / 2)*1.4*0.18*25
weight of each plate = total weight / no of plates = 4 always = total wt. / 4
direct tension in sloping bottom slab = weight of each plate* cosecθ =
tension on teach plate = Direct tension/4
A(st) = 1.5 T / 0.87.fy /0.87 fy = Tu*1000 N / 0.87*415
A(st) on each face = this Ast /2
here, 1.5 T = Design tension for /m width = T(u) = 1.5*(tension on each plate)
using 8 mm Φ bar , spacing(s) = π/4 *8*8 *1000/ (Ast on 1 side)
hence provide 8 mm nbar at s spacing
normal pressure Pn = γ.h.cosθ.cosθ + P(h).sinθ.sinθ+ w.s.cosθ
here, h = distance from centre of surcharge to centre of hopper. = height of surcharge/2 + height of cylindrical + height of hopper/2
Subtopic 1
ws = deifined in IS code = 25
P(h) = γ.h.cosΦ.cosΦ
Corner moment = P(n)*L*L/ 12
here, L = effective span = top width + bottom width/2 + 0.18 m
Mu = 1.5*M
Area of steel required for corner moment :: M(u) = 0.87*fy*Ast*d[1 - fy.Ast / fck.b.d
effective thickness of wall = small d = 180-30
spacing = using 10 mm Φ bar , spacing(s) = π/3 *10*1o *1000/ Ast calculated
Moment (+ve) at mid span
P(n)*L*L/8 - P(N)*L*L/12 = P(n)*L*L/24
Design moment = 1.5*M
Area of steel Ast:: M(u) = M(u) = 0.87*fy*Ast*d[1 - fy.Ast / fck.b.d]
spacing = using 10 mm Φ bar , spacing(s) = π/3 *10*1o *1000/ Ast calculated
Floating Topic