管と土の摩擦係数 土と鉄管 ポリエチレンスリーブ被覆時 固い地盤 0.5 0.4 中位の地盤 0.4 0.3 軟弱の地盤 0.3 0.2
sf*p*A*sin(θ/2) L' =------------------------------------------------------------- sin(θ/2)*μ*γ*hc*π*D2+(1/4)*cos(θ/2)*Ce*γ*(h2^2-h1^2)*R
sf*p*A*sin(θ/2)-(1/4)*cos(θ/2)*Lp*Ce*γ*(h2^2-h1^2)*R L' =------------------------------------------------------------- sin(θ/2)*μ*γ*hc*π*D2