涵洞水力计算

虑甲方排水要求,故选取涵洞 m25.5-2? K5+291.00 涵洞孔径计算(1 )选择涵洞孔径汇水面积: 20.65km F?采用经验公式,设计流量: ?? Fu-SQ mpp ???其中: 100 S p?,3.26 100 1SKu 71 .0p1?????,67 .01m76 .0 2?????, , ?? 67 .0 165 .03.26 100 76 .0Q????sm94 .41 3?设涵洞进水口净高: m0.2h d??涵前水深: m92 .187 .0 6 0.20.287 .0 hH d???????涵洞宽度: m97 .992 .1581 .1 94 .41 H581 .1 QB 2 32 3 p?????选一净跨径 m10 L 0?的钢筋混凝土盖板涵, 此时涵前实际水深: m92 .1L581 .1 QH 3 20 p???????????因此,进水口水深: m67 .1H87 .0H???查表 5-8 ,, 6 h??则涵洞净高 2.0m m004 .267 .15 6H5 6h d??????(2 )确定 ckckVVhh、、、此时,临界水深 m24 .1H6435 .0?? kh 收缩断面水深: m12 .19.0 kc??hh 收缩断面流速: sm6Vsm785 .3134 .0 92 .1134 .0 HV y 2 12 1c?????????????????临界流速: sm6Vsm41 .3V9.0V yck????(3 )计算临界坡度: 水力半径: m99 .024 .1210 24 .110 h2B hBP R k kk kk???????????? max 23 23 4k 2kk 2 2kki%304 .099 .0 41 .3016 .0R VnRC Vi???????????????满足要求,故选取涵洞 m0.20.52??