What is Canal Lining?
Canal Lining is an impermeable layer accommodated the bed and sides of canal to enhance the life and release limit of canal. 60 to 80% of water lost through leakage in an unlined canal can be protected by building canal lining.
Earthen Type lining
Compacted Earth Lining
Compacted earth linings are favoured for the canals when the earth is accessible close to the site of construction or In-situ. In the event that the earth is not accessible close to the site it becomes costlier to build compacted earth lining.
Compaction decreases soil pore sizes by displacing air and water. Decrease in void size increase the density, compressive quality and shear quality of the dirt and lessen permeability. This is accompanied by a decrease in volume and settlement of the surface. Appropriate compaction is essential to expand the stability and frost resistance (where required) and to diminish erosion and seepage losses.
Soil Cement Lining
Soil-cement linings are developed with mixtures of sandy solid, cement and water, which harden to a solid like material. The concrete substance should be least 2-8% of the soil by volume. However, larger concrete substance is additionally utilized. In general, for the development of soil-cement linings following two strategies are utilized:
- Dry-mixed method
- Plastic mix method
For erosion protection and additional strength in big channels, the layer of soil-cement once in a while secured with coarse soil. It is recommended the soil-cement lining should be protected from the climate for seven days by spreading around 50mm of soil, straw or hessian packs over it and keeping the cover saturated to allow proper curing. Water sprinkling should proceed for 28 days following establishment.
Hard Surface Canal Linings
Cement Concrete Lining
Cement Concrete linings are broadly utilized, with advantage justifying their generally high cost. They are though, sturdy, relatively impermeable and hydraulically efficient. Concrete linings are appropriate for both small and large channels and both high and low flow speed. They satisfy each purpose of lining
In the event of brick lining, bricks are laid utilizing cement mortar on the sides and bed of the waterway. After laying bricks, smooth completion is given on the surface using cement mortar.
This type of lining is built with dressed stone blocks laid in mortar. Properly dressed stones are not accessible in nature. Irregular stone blocks are dressed and chipped off according to requirement.