What Are Vibro Stone Columns? | Vibro Replacement Stone Columns

Vibro Stone Columns are used as one of the techniques for ground improvement at construction sites. Ground improvement is required when the properties of rock or soil need to be transformed to enhance the load-bearing capacity and strength of the ground.

In this article, you will get to learn all about the Vibro stone columns, advantages and disadvantages of Vibro stone columns.

What Are Vibro Stone Columns?

Vibro stone columns are the ground improvement technique used to improve the load-bearing capacity of the soil. The stone column consists of crushed coarse aggregates of different sizes.

Vibro Stone Columns are constructed by using a vibrator to fill in designed hollows with granulated gravels of distinct dimensions. This takes place when construction is initiated in areas of loose soil. The weak soil cannot bear the heavy loads of the structure due to its low bearing capacity.

The construction of the Vibro stone columns is one of the most versatile techniques which is used for the engineering of the ground.

The force of the vibrator, along with water jetting motion, bonds the granules into a compact and dense composition. This high-tech method can help the soil achieve a relative denseness of about 70-80% more than the original density of said ground.

The primary purpose of the Vibro stone columns is to improve the settlement characteristics of the soft soil and increase the load-bearing capacity and shear strength.

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Why Should You Use Vibro Stone Columns Be Used?

The use of Vibro Stone Columns helps cut down the soil’s compressible and permeable factors to make the construction of superstructures easily possible. This is required because not all soil types can bear the heavy loads of the structures.

The vibratory procedure of making and inserting stone columns into naturally weak soils moderates soil settlement issues.

Vibro stone columns help to increase the load-bearing capacity of the soil. The Vibro stone columns help to minimize the size of the foundation required for the structure, due to which the overall cost of the project gets reduced.

The stone column helps to densifying the soil through vibration and inserting the stone column into the soil and reinforcing the soil to create a soil mass that should be stiff.

The Vibro stone columns reduce the shallow foundation settlement, mitigates the liquefaction potential, and provides slope stabilization.

Factors that guide the designing of Vibro stone columns

• The type of soil
• The deepness of ground to be treated
• The expanse of the construction site to be treated

Applications of Vibro Stone Columns

There are various applications of Vibro stone columns in civil engineering that are as follows.

1. The stone columns are used in the rail, road embankments, power plants, bridge approaches, and abutments.
2. It is used in the construction of the foundation of lightweight structures, Industrial warehouses, and retaining walls.
3. Vibro Stone Columns help in implementing ways to maintain adequate bearing grades for the foundation of a building.
4. Vibro Stone Columns possess higher angles of inner friction and are firmer than the surrounding soil.
5. This promotes the shifting of load to the stone columns rather than inflicting the load on the weak soil.
6. It helps to reduce the settlement of the soil foundation.
7. The use of Vibro Stone Columns is applicable to soft soil grounds like sand, clay, silt, and other non-homogeneous soils.
8. Vibro Stone Columns help in cutting down compressible and permeable factors of such types of soil.
9. This method aids radial draining, thus improving the durability of constructions done on various naturally weak soils.
10. It also aids the prevention of damage at the work site by sustaining a drainage path, hence helping improve ground strength.
11. This type of stone column is best suitable for sandy soils.

Also Read: What Is Standard Proctor Test? | Uses of Standard Proctor Test | Standard Proctor Compaction Test Apparatus | Procedure of Standard Proctor Test | Advantages & Disadvantages of Standard Proctor Test

Vibro Replacement Stone Columns Process

• Proper care must be taken that the granulated gravels used in this process should be free of any silt or clay.
• The process of compacting granules is done in stages, making sure each stage achieves intensive compression to give maximal outcomes.
• The more compact the Stone Column will be, the better and sturdier the results of Construction will be.
• The surrounding soil, when networked with the stone fill, results in substantial ground for Construction.
• It should be taken care that stone columns be protracted through unsound soil to firm and sound ground bed to help in controlling of settlements.
• Vibro Stone Columns possess higher angles of inner friction and are firmer than the surrounding soil.
• This promotes the shifting of load to the stone columns rather than inflicting the load on the weak soil.
• The Vibro stone columns should be constructed by experienced engineers with the help of advanced equipment.
• Vibro Stone Columns give way to a sound foundation and support systems with dense ground and scope for more load-bearing.
• They give scope to processes like drainage, densification, reinforcement, etc. Vibro stone columns are planned to form various outline layouts according to the demand of multiple blends of loads and soil exploitation.

There are two approaches to the assembly of Vibro Stone Columns:

Top Feed Plan

This plan is also called the Non-Displacement Method or Bored Rammed Method. In this technique, the vibrator digs until it reaches the planned depth with the help of its heaviness and vibrations.

Soft unusable material is jetted away with the help of water. The granulated gravel is then supplemented into the hollow established by the vibrator by digging.

The gravel travels to the depths of the hollow and is compacted by the pulsing up and down motion of the heavy vibrator. This process is done over and over until a stone column is constructed.

Bottom Feed Plan

This plan is also called the Displacement Method or Vibro stone columns Replacement Method. In this technique, the vibrator digs until it reaches the planned depth with the help of its heaviness and vibrations.

The granulated gravel is then supplemented to the vibrator tip using a supply tube. Following this, the compaction process takes place until a stone column is constructed.

The Construction of the stone column requires an excavator with a vibrating probe to feed the stone deep into the ground with the help of the vibrating probe, which forms the vertical column of the stone.

Vibro Stone Column Design

There are three prevalent scheme advents by which the designing of Vibro Technologies is driven. They are:

• Increase in shear resistance
• Controlling settlement
• Liquefaction and the lateral spreading of the mitigation.

Advantages of Vibro Stone Columns

There are various advantages of Vibro stone columns that are as follows

1. The Vibro stone columns help to increase the load-bearing capacity of the soil.
2. It will scale down the foundation size, due to which the cost of the project gets reduced.
3. It will reduce the total and differential settlement.
4. Relieves probability of liquefaction at sites with tremor risks.
5. Makes construction on different types of granular land possible.
6. Allows working in areas with shallow footing, which leads to cost-effectiveness.
7. Maintains balance of slope at the site of work.
8. More economical than piling due to higher overall production rate.
9. Allows usage of thinner base slabs keeping it cost-effective.
10. Alternative to traditional ground improvement methods that make a lot of noise and vibration.
11. No downtime is subsequent to installing which results in the immediate rendering of the construction process.
12. The openness to the use of recycled concrete and gravel makes it an environmentally friendly option.
13. It is a cost-effective method for pilling and it is also an environmentally friendly method as recycled materials can be used.
14. It carries high shear stresses by acting as a stiff element and increases the stability of the embankment on the soft ground.

Disadvantages of Vibro Stone Columns

There are also some advantages of Vibro Stone columns that are as follows

1. Not suitable for organic soil areas or places that have inadequate lateral retention.
2. Challenging to apply at confined sites or areas that are environmentally unstable
3. Requires a broad and extensive analysis.
4. Requires repeated sampling to thoroughly understand and deflate risks.
5. The Vibro stone columns method is only effective for granular and non-cohesive soils.
6. The densification of the soil is generally achieved when the granular soil contains more than 12-15% silt or more than 2% clay.
7. The provision of the stone columns does not reduce the total consolidation settlement. The reduction depends on the stone columns‘ spacing, generally ranging from 2.0 to 3.0 c/c over the site.

Conclusion

The use of Vibro Stone Columns is an all-around technique for structuring any ground for construction. The heavy equipment machinery and critical planning used in the process of compacting Stone Columns are eligible to put up with construction on different soil conditions and provide other techniques to do so.

Ground that is weak for construction is enhanced and upgraded by densification, reinforcement, and drainage abilities of the Vibro Stone Columns introduced into the ground.

This renovated and reformed ground becomes available for complex construction and thus makes progress in the construction world a reality.

These methods can be applied to the construction work of commercial buildings, rail embankments, bridge piers, etc. New and better construction opportunities arise when such methods of tackling site problems are accepted in the construction and engineering front.