Ground improvement solutions are often used as alternatives to deep foundations or in combination with foundation systems, depending on site conditions and project requirements.
What is ground improvement?
Ground improvement includes a range of techniques used to modify or enhance the engineering properties of soil and ground conditions. These methods are applied to improve strength, stiffness, and stability, or to reduce settlement and deformation under load.
When is ground improvement used?
Ground improvement may be applied when:
- Existing soils lack sufficient strength or stiffness
- Settlement must be reduced or controlled
- Shallow foundations are preferred over deep foundations
- Construction is planned on loose, soft, or variable soils
- Project constraints require cost‑effective or low‑carbon solutions
Ground improvement is often considered as an alternative to deep foundations or as part of a combined solution. In some cases, improving soil strength and stiffness allows shallow foundations to be used. In others, ground improvement is used to reduce settlement, mitigate liquefaction, or complement deep foundation systems to achieve performance or constructability benefits.
Ground improvement process
Ground improvement techniques are selected based on soil type, loading conditions, and project constraints. Depending on site conditions, soils may be improved through densification, reinforcement, replacement, stabilization, or a combination of methods.
- Densification techniques use vibration or displacement to improve granular soils.
- Reinforcement involves constructing or inserting stiff elements within the ground to create an improved composite material.
- Stabilization methods improve soil properties by introducing cementitious or chemical binders, either by permeation in granular soils or through mixing in cohesive and mixed soil types.
For soft or compressible soils, wick drains (vertical drains) may be installed to accelerate consolidation and strength gain when soils are subjected to surcharge loading, reducing construction time and post‑construction settlement.
Subsurface voids can lead to settlement and structural instability. Keller's full range of void‑filling techniques includes compaction grouting, cement grouting, polyurethane grouting, and other specialized systems that permanently fill voids and stabilize the ground. These solutions are commonly applied to mitigate mine subsidence and stabilize sinkholes beneath existing structures and infrastructure.
Expansive clay soils can cause severe ground heave and damage to overlying structures. Keller uses grout/slurry injection and soil mixing techniques to treat expansive clays beneath structures and infrastructure, reduce swell potential, stabilize the soil matrix, and improve ground strength.
- Water injection to pre‑swell expansive clays before construction
- Grout/slurry injection to pressure inject lime or cementitious slurries into expansive clays, fill fissures, chemically improve the soil, and reduce shrink-swell behaviour
- Soil mixing to blend expansive clays with cement or lime binders and create stabilized soil elements with improved strength and reduced expansivity
Why choose Keller for ground improvement?
Keller offers a full range of ground improvement techniques and the experience to select the right approach for each site. Because we also deliver deep foundation and earth retention systems, we can evaluate alternatives and recommend the optimal solution or combinations of solutions.
Common uses
- Increase bearing capacity for foundations and slabs
- Reduce settlement and permeability
- Mitigate liquefaction potential
- Accelerate settlement
- Improve ground performance for embankments and earthworks
- Mitigate liquefaction potential
Related projects
Energy and utilities
Gas Plant Project
Through value engineering, Keller replaced the originally specified stone columns with Dynamic Compaction, delivering significant time and cost efficiencies while achieving the required performance criteria.
Commercial and leisure
Dubai Square Mall
Ground improvement works for a major landmark retail development in Dubai was successfully delivered through proactive execution and close coordination, achieving all key milestones within the required programme.
Infrastructure
DS 413/2 Sewerage & Drainage Tunnel
TAM grouting successfully delivered along a major tunnel alignment in Dubai, with approximately 1,000 m³ of grout injected under controlled pressure to support safe and reliable micro-tunnelling operations.
Infrastructure
Salwa 380KV BSP Substation
Keller successfully delivered a design-and-build solution for the BSP 380 kV Substation using large-diameter Vibro-stone columns, achieving the required bearing capacity, controlling settlements, and enabling an optimized reinforced concrete foundation design while mitigating liquefaction risks under seismic loading.
Energy and utilities
Synchronous Condensers Facilities
A performance-based ground improvement solution was developed to enhance foundation support and mitigate liquefaction risks, supported by rigorous testing to validate compliance with project design criteria for the two SC facilities sites.
