2. The distance between rain outlets should be 25 to 50 meters, the number of rain outlets connected in series with connecting pipes should not exceed 3, and the length of connecting pipes of rain outlets should not exceed 25 meters.
3. When the longitudinal slope of the road is more than 0.02m, the distance between rain outlets can be more than 50m, and its form, quantity and arrangement should be determined according to the specific situation and calculation. When the slope section is short, water can be collected at the lowest point, and the number or area of rain outlets can be appropriately increased.
4, the depth of the rain mouth should not be greater than 65438+/-0 meters, and according to the need to set up sludge chute. In case of special circumstances requiring shallow burial, reinforcement measures should be taken. The depth of rain outlets in areas affected by frost heaving can be determined according to local experience.