7×1.6×1.6/2+1.4×3×0.7×1.6×1.6/2+1.2×3×0.5×1.6×1.6/2=6.82+6.39+3.76+2.30=19.27(KN*m)轴力设计值为Mx/(rx×Wnx)=19.27×106/(1.05×93.68×103)=196N/mm2<215N/mm2.满足要求。铸铝承托弓强度验算:M=1.4×3.57×1.6×1.6/2+1.4×3×0.7×1.6×1.6/2+1.2×3×0.5×1.6×1.6/2=6.39+3.76+2.30=12.45(KN*m)注:图中单位以毫米计铸铝承托弓:Wnx=82.933cm3Mx/(rx×Wnx)=12.45×106/(1.05×82.933×103)=150N/mm2<200N/mm2.满足要求。二、基础计算:基础上部竖向荷载N=3.57+3×0.7×1.6+3×0.5×1.6=8+2.94+2.88=9.33基础和土自重G2=1.2×1×0.9×20=21.6KN基底应力验算N=G1+G2=30.93KN,Mx=19.27KN*m基底应力的最大值为:σmax=N/A+Mx/Wx=25.8+81.70=107.6(kPa)<[δ]=200.00(kPa),满足设计要求。偏心距e=M/1.35/N=19.27/30.93=0.46m>1.2/6=0.2mPmax=2×N/(3×1×(0.6-0.46))=43.2/0.36=120(kPa)<[δ]=200.00(kPa),满足设计要求。三、稳定性计算:倾覆力E=3.57×(1.6/2-1.2/2)+1.45×2.4×(0.2+2.4/2)+3×0.7×(1.6/2-1.2/2)+3×0.5×(1.6/2-1.2/2)=0.714+4.872+0.42+0.3=6.4KN抵抗力G=21.6×0.6=12.96KNG/E=2.025>1.6满足设计要求。
全文预览
