Side gutters are generally constructed parallel to the side of the road and it disposes the surface water efficiently. Below figure shows the side gutter or side drain in cutting and embankment provided for proper surface drainage.
The section of side drain is generally trapezoidal, but generally triangular side gutters are also provided in cutting. They are basically provided parallel to the road surface only when the designed depth of the side drains is less and the road is subjected to light traffic.
When the gutters or drains are additionally provided parallel to the road at higher level for collecting and disposing the surface water is known as catch water drain.
The catch water drain intercepts the large quantity of the surface water flow and also breaks the continuity of flow and thereby reduces the velocity of water and prevents the erosion and landslides and thereby protect the road pavement.
Catch water also help in reducing the size of side gutters or side drains. Sectional area of catch water drains are generally 0. If surface water flowing from the high level ground towards the road is large then it is desirable to take this water across the road at regular intervals and then allow this water to flow through the pipe drain constructed through the road embankment to the natural stream.
Sub-surface drainage is the system in which the sub-soil water from underside of road pavement is collected and removed efficiently. It is generally adopted to control the moisture content of road sub-grade. If the moisture content in the sub-soil increases, it can weaken the road structure. Hence it becomes more important to control the moisture of road sub-grade. Thus longitudinal drains, cross drain and impervious bituminous layer are provided to prevent the rise in sub-soil moisture or sub-surface moisture and its specially provided to control the capillary rise.
Water table can be lowered by providing longitudinal drains and cross drains below the pavement structure at the specified depth.
Longitudinal pipes are placed with open joints butting against each other and laid on a bed of sand, crushed stone of mm thick. The diameter of L-drain pipes varies from mm to mm. In addition to longitudinal drains, Cross drains C-drains or transverse drains consisting porous pipes or perforated pipes are laid cross from the center of the road and opened to the L-drains with slope of 1 in The diameter of C-drains varies from 60 to mm.
There arc two cases of providing the longitudinal and cross drains. Yes No. Page feedback. Feedback about this page: Feedback is required. Reference number:. Provide feedback on a Department of Transport and Main Roads service Please use our complaints and compliments online form to provide feedback about a service. Last updated 24 September Explore this site Popular Find a form Traffic cameras Find a customer service centre Traffic and road conditions Queensland road rules Driver licensing.
Looking for Annual report Buying or selling a vehicle Demerit points Getting a licence Learning to drive Registering vehicles Our projects. Back Discover CALS See how our current work and research is bringing new thinking and new solutions to some of today's biggest challenges.
Applied Economics. Global Development. We review and add new titles on an ongoing basis.
0コメント