89-2, 98-3, 07-1, 11-2
방파제 활동 안전율 계산
<조건>
케이슨 자중
W = w ⋅ A = 2 t / m 3 × 10 × 8 m 2 = 160 t / m {\displaystyle {\begin{aligned}W=w\cdot A&=2t/m^{3}\times 10\times 8m^{2}\\&=160t/m\\\end{aligned}}}
부력
B = w s A = 1 t / m 3 × 10 × 8 m 2 = 80 t / m {\displaystyle {\begin{aligned}B=w_{s}A&=1t/m^{3}\times 10\times {\color {red}8}m^{2}\\&=80t/m\\\end{aligned}}}
마찰력
f ( W − B ) = 0.6 ( 160 − 80 ) = 48 t / m {\displaystyle {\begin{aligned}f(W-B)&=0.6(160-80)\\&=48t/m\\\end{aligned}}}
파압
P = 1.5 w s h = 1.5 × 1 t / m 3 × 3 m = 4.5 t / m 2 {\displaystyle {\begin{aligned}P=1.5w_{s}h&=1.5\times 1t/m^{3}\times {\color {red}3m}\\&=4.5t/m^{2}\\\end{aligned}}}
파압에 의한 수평력
P H = P × H = 4.5 t / m 2 × 8 m = 36 t / m {\displaystyle {\begin{aligned}P_{H}=P\times H&=4.5t/m^{2}\times 8m\\&=36t/m\\\end{aligned}}}
안전율
F s = f ( W − B ) P H = 48 36 = 1.33 {\displaystyle F_{s}={\frac {f(W-B)}{P_{H}}}={\frac {48}{36}}=1.33}
