新规范双孔箱涵结构设计VIP免费

1、孔径及净空净跨径L0 =6m净高h0 =3.6m孔数m=22、设计安全等级一级结构重要性系数r0 =1.13、汽车荷载荷载等级公路 —Ⅰ级4、填土情况涵顶填土高度H =1m土的内摩擦角Φ =30°填土容重γ 1 =18.7kN/m3地基容许承载力[σ 0] =180kPa5、建筑材料普通钢筋种类HRB335主钢筋直径22mm钢筋抗拉强度设计值fsd =280MPa涵身混凝土强度等级C30涵身混凝土抗压强度设计值fcd =13.8MPa涵身混凝土抗拉强度设计值ftd =1.39MPa钢筋混凝土重力密度γ 2 =25kN/m3基础混凝土强度等级C15混凝土重力密度γ 3 =24kN/m3(一)截面尺寸拟定 (见图L-01)顶板、底板厚度δ =0.4mC1 =0.05m钢 筋 混 凝 土 箱 涵 结 构 设 计一 、 设 计 资 料二 、 设 计 计 算第 1 页，共 17 页侧墙厚度t =0.4mC2 =0.05m横梁计算跨径LP = L0+t =6.4mL = 2L0+3t =13.2m侧墙计算高度hP = h0+δ =4mh = h0+2δ =4.4m基础襟边c =0.2m基础高度d =0.5m基础宽度B =13.6m(二)荷载计算1、恒载恒载竖向压力p恒 = γ 1H+γ 2δ =28.70kN/m2恒载水平压力顶板处eP1 = γ 1Htan2(45°- φ /2) =6.23kN/m2图 L-01底板处eP2 = γ 1(H+h)tan2(45°- φ /3) =33.66kN/m22、活载汽车后轮着地宽度0.6m，由《公路桥涵设计通用规范》(JTG D60—2004)第4.3.4条规定，按30°角向下分布。一个汽车后轮横向分布宽>1.3/2m<1.8/2m故车轮压力扩散线相重叠，应按如下计算横向分布宽度a = (0.6/2+Htan30°)³2+1.3 =3.055m同理，纵向，汽车后轮着地长度0.2m0.2/2+Htan30°=0.677 m<1.4/2m故b = (0.2/2+Htan30°)³2 =1.355m∑ G =140kN手动输入车辆荷载垂直压力q车 = ∑G/(a³b) =33.83kN/m2车辆荷载水平压力e车 = q车 tan2(45°- φ /2) =11.28kN/m2(三)内力计算1、构件刚度比0.88 m0.6/2+Htan30°=第 2 页，共 17 页K = (I1/I2)³(h P/LP) =0.63u=2K+1=2.252、节点弯矩和轴向力计算(1)a种荷载作用下 (图L-02)涵洞四角节点弯矩MaA = MaC = MaE = MaF = -1/u² pLP2/12MBA = MBE = MDC = MDF = -(3K+1)/u² pLP2/12MBD = MDB = 0横梁内法向力Na1 = Na2 = Na1' = Na2'=0侧墙内法向力Na3 = Na4 = (MBA-MaA+pLp2/2)/Lp Na5=-(Na3+Na4)恒载p = p恒 =28.70kN/m2MaA = MaC = MaE = MaF =-43.54kN² mMBA = MBE = MDC = MDF =-125.17kN² mNa3 = Na4 =79.08kN Na5...