排水沟排水能力计算。

排水沟排水能力计算。 一、降雨强度计算 已知: 上海 ; 设计重现期P,2年 ; 设计降雨历时t,5分钟; 径流系数=0.9 计算: 设计降雨强度q,((17.812+14.668×Lg(2))/((5+10.472)0.796))×1000/6,418.66升/秒?公顷。 二、FX100排水沟水力计算 1、已知: 水深,0.12米 ; 沟宽,0.1米 ; 粗糙系数n,0.001 ; 2、计算: 计算时将U形排水沟分为上部矩形和下部半圆形计算。 1 矩形部分:水深70mm ，底宽:100mm;计算过程:湿周,2×0.07+0.1,0.24m ; 过流面积,0.1×0.07,0.007平米 ; 水力半径,0.007/0.24,0.0292m ; 流速v,((0.02922/3)×(0.0010.5))/0.001 ,3m/s ; 矩形天沟排水量Q,3×0.007×1000,21L/s 。 半圆形部分:半径为50mm;计算过程:湿周,3.14×0.05,0.157m ; 过流面积,0.5×3.14×0.05×0.05,0.0039平米 ; 水力半径,0.0039/0.157,0.0248m ; 流速v,((0.02482/3)×(0.0010.5))/0.001,2.69m/s ; 半圆形天沟排水量Q,2.69×0.0039×1000,10.49L/s 。 ——————————————————————————————————————————————— 3、FX100排水沟排水能力=21+10.49=31.49L/s 4、FX100排水沟基本资料: 2 三、FX150排水沟水力计算 1、已知: 水深,0.21米 ; 沟宽,0.15米 ; 粗糙系数n,0.001 ; 2、计算: 计算时将U形排水沟分为上部矩形和下部半圆形计算。 矩形部分:水深135mm ，底宽:150mm;计算过程:湿周,2×0.135+0.15,0.42m ; 过流面积,0.15×0.135,0.0203平米 ; 水力半径,0.0203/0.42,0.0483m ; 流速v,((0.04832/3)×(0.0010.5))/0.001,4.19m/s ; 矩形天沟排水量Q,4.19×0.0203×1000,85.06L/s 。 3 半圆形部分:半径为75mm;计算过程:湿周,3.14×0.075,0.2355m ; 过流面积,0.5×3.14×0.075×0.075,0.0088平米 ; 水力半径,0.0088/0.2355,0.0374m ; 流速v,((0.03742/3)× (0.0010.5))/0.001,3.54m/s ; 半圆形天沟排水量Q,3.54×0.0088×1000,31.15L/s 。 3、FX100排水沟排水能力=85.06+31.15=116.21L/s 4、FX150排水沟基本资料: 四、FX200排水沟水力计算 4 ——————————————————————————————————————————————— 1、已知: 水深,0.26米 ; 沟宽,0.20米 ; 粗糙系数n,0.001 ; 2、计算: 计算时将U形排水沟分为上部矩形和下部半圆形计算。 矩形部分:水深160mm ，底宽:200mm;计算过程:湿周,2×0.16+0.2,0.52m ; 过流面积,0.2×0.16,0.032平米 ; 水力半径,0.032/0.52,0.0615m ; 流速v,((0.06152/3)×(0.0010.5))/0.001 ,4.93m/s ; 矩形天沟排水量Q,4.93×0.032×1000,157.76L/s 。 半圆形部分:半径为100mm;湿周,3.14×0.1,0.314m ; 过流面 5 积,0.5×3.14×0.1×0.1,0.0157平米 ; 水力半径, 0.0157/0.314,0.05m ; 流速v,((0.052/3)×(0.0010.5))/0.001 , 4.29m/s ; 半圆形天沟排水量Q,4.29×0.0157×1000,67.35L/s 。 3、FX100排水沟排水能力=157.76+67.35=225.11L/s 4、FX150排水沟基本资料: 6 五、FX220排水沟水力计算 1、已知: 水深,0.33米 ; 沟宽,0.27米 ; 粗糙系数n,0.001 ; 2、计算: ——————————————————————————————————————————————— 计算时将U形排水沟分为上部矩形和下部半圆形计算。 矩形部分:水深220mm ，底宽:220mm;计算过程:湿周,2×0.22+0.22,0.66m ; 过流面积,0.22×0.22,0.0484平米 ; 水力半径,0.0484/0.66,0.0733m ; 流速v,((0.07332/3)× (0.0010.5))/0.001,5.54m/s ; 矩形天沟排水量Q,5.54×0.0484×1000,268.14L/s 。 7 半圆形部分:半径为110mm;湿周,3.14×0.11,0.3454m ; 过流面积,0.5×3.14×0.11×0.11,0.019平米 ; 水力半径, 0.019/0.3454,0.055m ; 流速v,((0.0552/3)×(0.0010.5))/0.001 ,4.57m/s ; 半圆形天沟排水量Q,4.57×0.019×1000,86.83L/s 。 3、FX100排水沟排水能力=268.14+86.83=225.11L/s 4、FX150排水沟基本资料: 8 ———————————————————————————————————————————————