Predimensionare fundatie

S-a ales ca sistem de fundare fundatie continua din beton armat sub sirurile de stalpi ai constructiei .

Stabilirea latimii talpii fundatiei

p_ef p_conv , unde p_conv=240 KN/m2

p_ef= (P₁+P₂+P₃+P₄)/(B·L)+ g_med · D_f p_conv   

L = 1 2+4.8+5.1+4.2 = 16.10 m

B· L= 16.10· B

(356.40+616.75+572.02+294.80)/(B

1839.97/B/16.10=180-20·1.85=143

B = 1839.97/16.10/143= 0.79m

alegem B=1.00m

Stabilire dimensiuni pe verticala ale fundatiei

H= (1/3 ; 1/6) l_max

l_max= max(5.1,4.8,4.2) = 5.1

H = (1.70;0.85) alegem H = 1.5 m

H` = (1/3 ;1/2) H = (0.50; 0.75)

alegem H`= 0.55 m

Verificare ansamblu fundatie

Afundatie = 11.20∙14.50-3.80∙5.00-4.10∙5.00-3.20∙5.00-3.80∙3.80-4.10∙3.80-3.20∙3.80

Afundatie = 64.72 m ²

G_fundatie = 1.20∙20 kn/m³­­­­ ∙64.72 m²∙1.85 m = 2873.568 kn

N _stalpi = 301.56 + 617.53 + 356.90 + 390.15 + 616.75 + 487.55 + 572.02 + 269.34 + + 294.80 + 552.68 = 4459.28 kn

G_placi = 953.888+379.568+476.944 = 1810.401 kn

G_grinzi = 803.05+16.533= 819.583 kn

G_{pereti demisol} = ((3.55+4.65+3.75)∙2 +(4.35+5.55)∙2)∙0.20∙2.43 ∙25 kn/m^{3 ­}_­­= 530.955 kn

G_total = 4459.28+2873.568+1810.401+530.95+819.583 = 10500 kn = 1050 t

p_{a med} = pc = 180 Kpa

p_{a max} = 1.4∙ pc = 252 Kpa

Ex / A = 281 tm / 1050 t / 14.5m = 0.018 => μ = 1.11

P_max = 1050/ 64.72 ∙ 1.11 = 18.008 < 1.4 ∙ 18 = 25.2

P_med = 1050/64.72 = 16.22 < 18 = p_conv

Fundatia cadrului transversal

N= 301.56+617.53+356.40 = 1275.99 Kn

M= 32.27+38.53+41.19-301.56∙5.40-617.53∙0.60+356.40∙5.40+77∙4.30 +

+ 80∙5.40 = 800.708 Kn

A = 11.20∙1 = 11.20 m²

W= 11.20² ∙ 1 / 6 = 20.906 m³

P_max,min = N/A + M /W

P_max = 1275.99 / 11.20 + 800.708 / 20.906 = 152.22 Kn / m²

P_min = 1275.99 / 11.20 - 800.708 / 20.906 = 75.627 Kn / m²

P^med = 113.923 kn / m ²

Pereti demisol :

G = 2.43∙0.20∙25∙11.20 = 136.08 kn

G_f = 0.7∙0.55∙11.20∙25 = 107.8 kn

Nf = 1275.99+136.08+107.8 = 1519.87 kn

M = 32.27+38.53+41.19+80∙5.40+77∙4.30 = 875.09 kn m

Ex /L = 875.09 / 1519.87 / 11.20 = 0.05 <0.15 => pmin > 0

μ= 1 + 6 Ex / L = 1.30

Pmax= 1519.87 / (11.20∙0.70)∙1.30 = 251.875 Kn /m²

Calcul grinda de fundare

Se cunosc:

R_c = 12.5 N/mm² (beton C20/25 )

R_a = 300 N/mm² ( otel PC 52)

h_pl = 0.10 m

h_grd = 0.550 m

h₀ = 0.515 m

P_{med 2} = 13.275 t/m²

M_inc = P_{med 2} ∙ 5.0 ² / 4 = > M_inc = 132.75 ∙ 5.0 ² / 12 = 276.56Knm

A_a R_a = b x R_c

=> x = h_o [ 1- M / ( b h_o² R_c ) )]

=> A_{a nec} = b x R_c / R_a

x = 0.515 ∙1000∙( 1- (1-2∙ 76.56 ∙ 10⁶ / (5000 - 515 ² ∙ 12.5 ) = 8.665 mm

A_anec = 5000 ∙ 8.665 ∙ 12.5 / 300 = 1805.219 mm ²

A_{a ef} = 1884 mm ² ( 6