30.解：(1)直钢筋（图a) 一根钢筋净长=L一2c十2X6.25d =8000-2×25+6.25×16×2 =8150mm(1分) 二根钢筋长=2×8150 =16300mm =16.30m(1分) (2)弯起钢筋（图b) 一根钢筋净长=L一2c+2×0.414H’+2×6.25d =8000-2×25+2×0.414×450+2×6.25×16 =8000-50+373+200 =8523mm(1分) 二根钢筋长=2X8523 =17046mm =17.05m(1分) 箍筋（图d)末端应作135°弯钩，弯钩平直部分的长度e,对有抗震要求的结构不应小于箍筋 直径的10倍。 (3)一根箍筋长度 L=(a-2c+2d)×2+(b-2c+2d)×2+24d; =(500-2×25+2×8)×2+(300-2×25+2×8)×2+24×8 =932+532+192 =1656mm(2分) 箍筋数量n=(8000一100)/200+1 =40.5 取n=41根(1分) 一根粱箍筋总长=41×1656 =67896mm =67.896m(1分) 170930. (l 图a) 一根钢筋净长 2 5 =8000.,-2X25+6.25X16X2 =8150mm(l 二根钢筋长 =16300mm =16.30m(l (2) 钢筋 图b) 一根钢筋净长白 2 c 414H'+2X6. 25d =8000-2X25+2XO. 414X450+2X6. 25X16 =8000一50+373十200 =8523mm(l 二根钢筋长 =17046mm =17.05m(l 箍筋〈图 )未端应作 5。弯钩，弯钩平直部分的长度e，对有抗震要求的结构不应小于箍筋 直径的 (3) L = (a-2c+2d) ><:2 十(b-2c+2d)X2+24d; =(500-2X25+2X的X2+(300一2X25+2X8)X2+24X8 =932+532+192 = 1656nu;n(2 箍筋数量 =(8000-100)/200+1 =40.5 取n=41 (l 一根梁箍筋总长百 =67896mm =67.896m(l 1709