Ground Improvement techniques

Ground Improvement techniques- 

How to improve the ground quality?

Some times soil condition is poor,Then we need to improve the quality of soil by ground improvement techniques.Here i shared most common techniques that are widely used in construction.

What is ground improvement?

By looking at words you can easily understand that Ground improvement is something that improve the quality and condition of ground.

One important terms that is highly related with Ground improvement is Techniques.

Well the definition looks like:
Ground improvement techniques are some vital construction methods which helps or improve the ground conditions to make the most suitable condition which need to be achieved for a construction project.

Why we need Ground improvement techniques?

As i said before,this method is used to improve the ground quality and now i will discuss why we need this? How important is this?

There are many bigger structures like high-rise-building,pavement,bridges etc are supported by foundations which transfer the total structural load to the soil.

For example,say a high-rise building is to be constructed on a particular type of soil,thus if that soil is unable to take that much of load then it will cause big amount of settlement and many more issues will arrive.

Some parameters that used to determine a soil's property are given below-

• Shear strength
• consolidation
• compaction
• permeability

So,before the construction process you should ensure that the soil on which the structure will be constructed should take care of these parameters.

In this situation the concepts of Ground improvement techniques are evolved.

Types of ground improvement techniques

This are various types of techniques are available and some techniques are emerging.

1.Mechanical modification-

The basic concept in mechanical modification is Compaction which increases the density of material.

By applying stress to a soil,it can be observed that the porosity is reduced and shear strength of soil increased.
In this case when we apply high amount of load to the soil,the free voids or air are displaced from the soil pores.

These are some most common equipment which are generally used to compact the soil:

Image source:By United States Air Force, MSgt. Rickie D. Bickle [Public domain], via Wikimedia Commons

• Vibratory roller
• Sheepsfoot roller
• Grid roller
• Smooth wheeled roller

2.Ground reinforcement-

This techniques helps to improve load carrying capacity of soil by increasing the soil strength.

The main mechanism of soil reinforcement is Friction between soil and reinforcing element that added to the soil.

Actually we have seen that,In reinforced concrete steel is used to take the most of the tensile load,similarly when we add some reinforced elements(Geo grids,Steel grids,Geo membrane) into the soil and that element will take all the additional load.

Now a days Fibre reinforced concrete is trending.

 Advantages

• The maximum amount of load that is transferred to the soil will be taken care by the friction(b/w soil and reinforcement).
• It hugely increases the load carrying capacity of soil
• This leads to fast construction
• Achieves long term durability

3.Hydraulic modification-

The basic concept behind the Hydraulic modification is to increase the shear strength of soil by removing some amount of water from soil.

This is important because when water content of soil is high the shear strength of soil gets reduced.

Removal of water from soil is done by increasing the drainage and pre-fabricated vertical drains.

4. Vibro-compaction methods-

The principle of vibro-compaction method is using the vibratory energy to reduce the friction force between soil particles and thus the densification of soil becomes easier.

Performance sequences-

• Penetration-Vibrator is penetrated to the required depth of ground by vibration and aid of water to the required depth.
• compaction-Soil is then compacted by vibratory energy and get more densified.
• Backfill-The compaction of soil is achieved by backfill from the top or by in-situ soil.

By applying this ground improvement techniques we can compact a ground upto a depth of 70 meter 

 This technique is most suitable for medium to coarse-grained sand with a less amount of silt.
But in case of cohesive-soils this method is not suitable as cohesive soils do not responds to vibrations.

Image source:www.vibro-gmbh.com

5.Stone column or Vibro replacement techniques-

Stone column is a techniques that is used to increase the load bearing of soil and reduces the settlement.

Basically a excavator is used with a vibrating probe to penetrate the ston-column into the ground.

Modulus of elasticity of stone column is higher than the soil thus stone column is able to take more loads than soil.

 sandy soils is generally suited for stone-column technique.

summary-

As we have discussed Ground improvement techniques are very much important in the sense of construction.
This helps to achieve most suitable amount of strength,permeability,settlement etc.

I Hope you liked this.share this info with your friends.