Ground Improvement: Introduction and Common Types

Key Takeaways

Ground improvement enhances soil strength, stability, and load-bearing capacity, making weak ground suitable for construction.
Common methods include compaction, drainage, grouting, and geosynthetics, each designed to address specific soil conditions.
Selecting the right technique depends on soil type, project requirements, and performance goals such as settlement control and stability.

What Is Ground Improvement and Why Is It Important?

Have you ever wondered how buildings, roads, or ports are constructed on weak or soft ground?

Ground improvement is a geotechnical engineering process used to modify soil properties so it can safely support structures. Instead of removing unsuitable soil, engineers improve it in place to meet design requirements.

This approach is widely used because it:

Increases soil strength and stiffness
Reduces settlement and deformation
Improves drainage and stability
Provides a cost-effective alternative to deep foundations

In countries like Malaysia, where soft clay and reclaimed land are common, ground improvement is essential for safe and sustainable development.

When Is Ground Improvement Required?

Ground improvement is typically used when:

Soil is too soft or loose to support loads
Construction is planned on reclaimed land or clay soils
There is a risk of excessive settlement or instability
Deep foundation systems are too costly or impractical

In such cases, ground improvement provides a practical alternative to excavation or piling, improving soil performance without major structural changes.

Common Types of Ground Improvement Methods

Ground improvement techniques can be broadly categorised based on how they modify soil behaviour.

1. Prefabricated Vertical Drains (PVD)

Prefabricated vertical drains are prefabricated geotextile filter-wrapped plastic strips with molded channels.

Also known as band drains or Wick Drains, prefabricated vertical drains serve as drainage paths to take pore water out of soft compressible soils that consolidate faster under a constant surcharge load.

Benefits

Accelerated drainage
High-speed prefabricated vertical drain installation

Common Uses

To accelerate drainage
Applicable in soft, saturated fine-grain soils, such as peat, dredge fills, silts, sludges, clays, and mine tailings, with large pore capacity and normally saturated
Consolidate leach pads and tailing ponds

👉 Often combined with surcharge loading or vacuum consolidation for faster results.

2. Dynamic Compaction (DC)

Dynamic compaction is a ground improvement technique that involves the controlled impact of a crane hoisted weight, (usually around 10-30 tonnes), falling in a pre-determined grid pattern. DC aims to improve loose, granular soils and fills.

Benefits

Capable of compacting a wide variety of weak soils
Dynamic compaction leaves a site clean and debris-free
Construction can commence immediately after the dynamic compaction is completed
Reduced settlement
Can avoid the removal of compressible, contaminated fills
Increased bearing capacity
Treated granular soils and fills have increased stiffness, density, and friction angle
Can greatly improve soil conditions on marginal sites to extent that deep excavation or piling isn’t needed during the construction of shallow foundations

Common uses

Reduces settlement
Increase bearing capacity
Decrease sinkhole potential
Mitigate liquefaction

👉 A cost-effective method for large-scale ground improvement projects.

3. Vibro Compaction (VC)

Vibro compaction is an old ground improvement method that uses a downhole vibrator to densify clean, cohesionless granular soils.

Benefits

Can be adjusted to different types of soil conditions and foundation requirements
Noise levels are negligible during production
Can be carried out to almost any depth
Relatively quick execution so subsequent structural works can follow very quickly
VC uses natural materials which makes it environmentally friendly
Maintains original site elevation where backfill is used
This versatile ground-improvement method assures quality
Offers an economical solution for ground improvement

Common uses

Reduce foundation settlement
Increasing stiffness
Increase bearing capacity, as such, allows a reduction in footing size
Highly effective for compacting reclaimed lands
Reduce permeability
Increase slope stability
Permit construction infills
Prevent the earthquake-induced lateral spreading
Mitigate liquefaction potential under a seismic event
For increasing shear strength

👉 Particularly effective for improving loose sand deposits.

4. Deep Soil Mixing

Deep soil mixing involves two methods: wet and dry method.

a. Wet Method

The deep soil mixing wet method improves the characteristics of weak soils by mechanically mixing them with cementitious binder slurry.

Benefits

Quiet and vibration-free
The use of readily-available materials make it environmentally friendly
Very economical
Flexible in application
Reduces construction time
Operations can be done at low temperatures
Almost no spoil
Can replace more expensive deep foundation methods

Common uses

Retention systems and excavation support
Road and railway embankments
Bridge supports and abutments, wind-turbine foundations
Slope stabilization
Support of pad, slab, and strip foundations

b. Dry method

The deep soil mixing dry method improves peats, soft, high moisture clays, and other weak soils, by mechanically mixing them with the dry cementitious binder.

Benefits

Flexible in application
Environmentally-friendly as it uses readily available materials
Almost no spoil
Quiet and vibration-free
Reduces construction time
Operations can be done at low temperatures
Can replace more expensive deep foundation methods
Economical

Common uses

Mitigate liquefaction
Applicable in high-moisture content soils and (oftentimes) in high groundwater conditions, to allow chemical reaction of the soil and groundwater with stabilizing binders injected in dry form
Increase bearing capacity
Fixate contaminants in situ materials
Increase global stability
Decrease settlement

This method produces soil with higher strength and lower compressibility, making it suitable for heavy structures.

5. Rigid Inclusions (RI)

Rigid inclusion is a ground improvement technique that uses high-deformation modulus columns constructed through compressible soils to increase bearing capacity and reduce settlement.

Benefits

Can be used in all construction sectors and applied for most soil types and structures
Allows the use of shallow foundations to support structure on compressible soils
Minimal spoil
Increases the bearing capacity of weak soils, especially for high loads
Highly efficient in reducing settlements (reduction factor ranges from 3 – 8)

Common uses

Embankments for road and rail
Industrial flooring
Warehouses
Public buildings
Commercial and industrial buildings
Residential buildings
Wind turbines
Terminals and storage tanks

👉 Commonly used for warehouses, highways, and heavy foundations.

Quick Comparison of Ground Improvement Methods

Method	Best Soil Type	Main Function	Key Advantage
PVD	Soft clay	Drainage	Fast consolidation
Dynamic Compaction	Loose fill	Densification	Cost-effective
Vibro Compaction	Sand	Densification	Improves stiffness
Deep Soil Mixing	Clay	Stabilisation	High strength
Rigid Inclusions	Weak soils	Load transfer	Settlement control

Why Ground Improvement Is Critical in Modern Construction

With increasing land scarcity, many developments are built on challenging soil conditions.

Ground improvement enables:

Construction on previously unusable land
Reduced reliance on expensive foundations
Improved long-term performance and safety
Faster project completion

It has become a standard engineering solution for infrastructure, ports, highways, and industrial developments.

Conclusion: A Smarter Approach to Soil Engineering

Ground improvement is not just about fixing weak soil—it’s about unlocking the potential of land for safe and sustainable development.

Mechanical methods improve density
Chemical methods enhance strength
Geosynthetics and inclusions provide reinforcement

The most effective projects combine multiple techniques to achieve:

Stronger, more stable, and long-lasting foundations

Vision and Expertise-Focused

As part of the growing field of Geosynthetics Malaysia, GSSB continues to lead through innovation, engineering excellence, and a deep understanding of local infrastructure needs. Our team is driven by the vision to deliver quality solutions that last.
Learn more about who we are and what drives us.