Summary 

A major residential development in Sandyford, South Dublin required remediation beneath foundation elements after voids and weak ground conditions were identified at basement level. Mainmark delivered a targeted ground improvement and void filling programme using Teretek® engineered resin injection technology beneath 110 pad foundations and 6 stair core foundations. The works were completed within 15 site working days, enabling construction to continue without significant programme delays. 

Challenge 

During construction of the high-rise residential development, investigations identified voids and localised weak ground beneath sections of the basement slab and foundation system. The client required a solution that would: 

• Fill existing voids beneath foundation elements. 

• Improve ground conditions and foundation support. 

• Minimise disruption within a live construction environment. 

• Work within restricted basement access conditions. 

• Avoid delays to the construction programme. 

The treatment area included approximately 110 pad foundations and 6 stair core foundations, requiring a practical and efficient remediation solution. 

Solution 

Mainmark deployed its proprietary Teretek® engineered resin injection technology to provide targeted void filling and ground improvement beneath the affected foundations. 

Using small diameter access holes, a high-strength structural polymer (40 N/mm² compressive strength) was injected beneath each foundation. As the resin expanded it: 

• Filled existing voids. 

• Densified weaker soils. 

• Increased ground stiffness. 

• Enhanced foundation support. 

The compact equipment footprint and minimally invasive installation process allowed works to proceed efficiently within the basement environment while construction activities continued elsewhere on site. 

“This project highlights the value of our Teretek® solution as a fast, cost effective alternative to traditional foundation methods. We were able to complete the works with minimal impact on the wider programme, while maintaining flexibility within a constrained environment. The fully monitored nature of our process also gives clients confidence in the performance and reliability of the outcome.” 

David Hedley, Infrastructure Lead 

Outcome 

• Voids beneath foundation elements successfully filled. 

• Ground conditions improved beneath 110 pad foundations and 6 stair core foundations. 

• Enhanced support provided to critical structural foundations. 

• Minimal disruption to ongoing construction activities. 

• Avoided the need for extensive excavation and reconstruction works. 

• Enabled the development to progress with confidence and maintain programme momentum.