8 WAYS TO CONTROL SOIL EROSION AT CONSTRUCTION SITES

Soil Erosion At Construction Sites

Soil erosion is a major concern for construction sites, especially if the project is very large.Most of time it is neglected by the Site Engineers or Supervisors.At construction sites it occurs due to heavy runoff due to rain or any other construction activities result in the washing away of soil, which is a slow process but if not rectify initially can result in delay of project which increases the overall cost of project.

Soil erosion can be caused by a variety of factors.Depending on this factor and the severity of the issue, solutions vary.The control of soil erosion helps preserve and protect the construction site and the structure.

Measures To Control Soil Erosion At Construction Sites.

1. Divide the project into sections.
2. Minimize disturbed area on the construction site.
3. Runoff water control method
4. Slope protection
5. Soil stabilization
6. Dewatering
7. Sediment control traps
8. Construction entrances

1. Divide The Project Into Sections

This is a very effective method to control soil erosion at construction sites.In this method working lands at site are divided into different sections.

2. Minimize Disturbed Area On The Construction Sites

During the preparation of a site for construction, it is advised to disturb only those area which are required  for the project.The remaining area of the site should be left undisturbed to protect the topsoil.

3. Runoff Water Control Methods

Some off the methods used to control the runoff water within and around the construction sites are as fallows:

• Geotextile: It is a commonly used for erosion control and soil improvement in a variety of construction projects such as road, pipelines and embankments.Depending on the application, geotextiles may have an open mesh weave, a warp-knitted structure or a closed fabric or nonwoven surface.The specific type of geotextile used is based on several criteria, including separation, filtration, drainage, reinforcement, sealing and protection.

• Soil Nail: Soil nail provides a resisting force against slope failures and offers relatively quick installation.The procedure involves drilling into the soil and placing steel bars into it.

• Riprap: It is a commonly used technique to protect soil from erosion in areas where there is a high degree of concentrated runoff. Riprap is a layer of very large stones interlocked together to act as a barrier on slopes that are unstable because of seepage problems or areas that are receiving a large concentrated flow.Large stone aggregate is poured onto geotextile membranes to keep the ground from being carried away by water.

• Turbidity Barriers: Turbidity barriers are useful in multiple ways, it can prevent soil erosion as well as water contamination.They are typically made of a geotextile membrane that floats and is anchored to the bottom of the water body with weights and used for sediment control.

• Articulated Concrete Blocks: Articulated concrete blocks are available in a thickness of wide variety and shapes.They are used as sloping structure on waterway embankments or manmade drainage systems.

• French Drains: It is a underground piping system called drain tile.The drain tile may also be performed to allow water to seep into the soil below the tile, while excess water travels to the exit point.French drains are installed with a slope of about 1 inch of drop per 10 feet of horizontal run.

4. Slope Protection

The slope protection can be protected by several methods in order to control soil erosion.Some of the method are as fallows:

• Silt Fencing: The purpose of silt fencing is to retain the soil on disturbed land at construction site.It is a temporary sediment barrier made of porous fabric.

• Fiber Rolls: It is a temporary erosion control and sediment control device used on construction sites to protect water quality in nearby streams, rivers, lakes and seas from sediment erosion.It is made of straw, coconut fiber or similar material formed into a tubular roll.Each fiber roll is installed on a horizontal contour level in shallow trenches 2 to 4 inches deep and fastened to the ground with wooden stakes.

• Mats: Mats laid on the soil surface to protect against the washout of soil due to action of rain and surface water.It is also often to provide surface protection when used with slope stabilisation and soil retention system such soil nailing, soil panels and soilcell.

5. Soil Stabilization

Soil stabilization is a physical or chemical treatment which increase or maintain the stability of a soil or improve its engineering properties.It can be achieved either temporary or permanently depending on the requirement of the project.The use of wood binders, mulch and blankets can act as a temporary measure while the permanent methods include seeding, channel stabilization, green buffer and planting. 

6. Dewatering

Dewatering is a term used to describe the action of removing groundwater or surface water from a construction site.Normally the dewatering process is done by pumping or evaporation.

7. Sediment Control Traps

Runoff water on construction sites can be reduced by employing sediment control traps or basin.These units help the sediments to settle before the water is discharged.The sediment basins are constructed with a capacity to store at least two year of stormwater.

 

8. Construction Entrances

A stable construction entrances mainly made up of crushed stone helps to reduce the amount of sediment getting carried away.This entrance required regular maintenance  and it is made at a length of 50 feet.