σn=a,/1-0.43()2J=2351-043()/=18.7Ma P=Aa=2×8.367×104×181.7×10°=304KN 安全因数 P304 2.02 P150) ] . MPa . [ . ( ) ] [ . ( c cr s 18 7 123 89 3 1 0 43 235 1 0 43 2 2 = − = − =     Pcr A cr 2 8.367 10 181.7 10 304kN 4 6 = =     = −  2 02 150 304 . P P n cr 安全因数 = = =