Erosion of soil 3

[Geokhan]

Rienforced concrete chutes have been constructed on highyway embankment side slope. Rain water erode almost all the material beneath the chutes. How we can correct this problem to stablized the chutes. Is there any proper method or remedy for this issue.

 

[EireChch]

Water flowing down steep slopes is always going to erode soil, especially granular soils that are often used to form embankments.

There are spray on proprietary applications that can be used to "stabilise" the soil but their effective ness is questionable. Mixing the embankment with 2% cement will also help improve its resistance to erosion.

The best method though is to reduce the chance of water getting under the spillway. Direct surface water away, ensure joints are sealed properly.

 

[Geokhan]

Great Eire...here the erosion will be controlled by stone pitching and then motor grouting will be done. But this issue come before stone pitching. How and what material will be good to fill the space beneath the chute. Becouse if we dump soil thn how we will compact that

 

[Geokhan]

Reference pic

 

[GeoPaveTraffic]

Remove the concrete, grade a swale, and line the swale with riprap. I've never seen concrete chutes, ditches, or grouted riprap work for very long.

Mike Lambert

 

[cvg]

it is difficult to keep the water in the chute. High velocity, supercritical flow tends to form waves and hydraulic jumps and requires substantial freeboard. splash over will run under the chute and erode the base material. if the slope is steep than headcutting will soon occur. the chute should be enlarged to contain the water and the edges should be protected with rock or concrete. filter material should be used under the rock. un-compacted, dumped soil is not recommended. base material under the chute should be good granular structural fill, properly compacted. if that is too difficult to construct, then CLSM might be a better choice. replacing the concrete chute with gabions or a pipe down drain might be a good alternative.

edit:
after reviewing the photo, it is clear that the lack of an inlet structure to the chute is probably the root cause. and furthermore, the chute looks far too small to handle anything other than a trickle of water.

 

[Geokhan]

Can we save these damaged chutes.How?

 

[EireChch]

Good recommendations by cvg and GPT, you can probably save the chute. Remove it temporarily, remove soft material beneath and fill with flowable fill.

That will last for a while (5-10 years?) but as cvg said, if you dont address the problem of chute size and inlet then you will still get water existing and flowing beneath. This will start to remove material from around your new flowable fill.

Heavy rains will contribute to erosion too, as I said, direct stormwater away and seal as best you can.

 

[Geokhan]

Thank you every one