Zero-excavation villa pad foundation repair in Nad Al Sheba, Dubai

Challenge

The structure exhibited signs of settlement, particularly around the font of the garage structure.

During site investigation, the root cause was clearly identified:

• A significant water supply leak from a broken pipe beneath the foundation
• Resulting in loss of soil strength and localised softening
• Creation of wet, weakened granular soils with reduced bearing capacity

This is a classic UAE failure mechanism:

water ingress → loss of fines / structure → rapid drop in stiffness → settlement

Ground conditions

Trial pit logging confirmed:

• Gravelly sand and sandy gravel layers near surface
• Underlain by fine to medium sand (slightly silty)
• No competent founding layer identified within shallow depth

Pre-treatment testing dynamic probing showed:

• Very loose to loose conditions
• Equivalent SPT N60 ≈ 2–12

This is not acceptable for pad foundations—you’re sitting on borderline collapse-prone soil when wet.

Limitations of traditional solutions

Conventional approaches would have included:

• Excavation and replacement (high disruption, not feasible under existing structure)
• Underpinning or piling (costly, slow, and excessive for this scale)
• Cement grouting (poor control in loose granular soils, risk of washout)

None of these address the combination of weak soil + water-affected zones effectively.

Geobear ground improvement solution

A controlled geopolymer injection solution was adopted to:

• Densify loose soils
• Fill voids caused by washout
• Restore stiffness and bearing capacity

Key parameters:

• 12 injection points installed beneath pad foundations
• 16 mm drill holes through foundation elements
• Treatment depth: ~1.5 m below foundation level
• Total material used: 324 kg

Execution:

• Bottom-up injection methodology
• Multi-level treatment using staged extraction

• Expansion ratio: ~10–15×

Execution

Works were carried out under real constraints:

• Existing occupied structure
• Restricted access
• Live services (confirmed via trial pits)

• Real-time laser monitoring to prevent unwanted heave
• Injection staged and adjusted dynamically

• Visual confirmation of material migration in voided zones

Results

To assess the effectiveness of the treatment, DCPT testing was carried out pre and post the injections, see graph below.

Interpretation of the results

DCPT results (converted to N60):

• Before: N60 ≈ 2–12 (very loose to loose)
• After: N60 ≈ 10–40+ (medium dense to dense)

Most improvement observed at:

• 1.8 m to 2.6 m depth

Critically:

• Weak layers (N60 < 5) were eliminated

Bearing capacity improvement

Result

• 2.3× increase in allowable bearing capacity

This is not marginal—this is a full performance upgrade.

Outcome & benefits

• Settlement mechanism identified and addressed at source
• Soil transformed from structurally unreliable → competent load-bearing layer
• No excavation, no structural downtime, and no relocation for household
• Fully controlled, targeted intervention

Key engineering insight

This project highlights a critical point: in UAE conditions, water leakage + sandy soils = rapid structural risk escalation. 

The solution was not just strengthening—it was:

• stabilizing a degraded soil system
• restoring effective stress conditions
• rebuilding bearing capacity in situ

Summary

The Geobear soil  injection treatment successfully:

• Eliminated weak soil layers
• Increased density and stiffness
• Delivered a 2.3× improvement in bearing capacity
• Provided a fast, non-disruptive alternative to traditional methods