The office building (20m x 15m), attached to a distribution warehouse (205m x 80m), had sunk by up to 70mm and needed to be raised and re-levelled to ensure the business could operate safely. The smaller building was regularly used by staff as it housed the main office and staff amenities. It was therefore vital to maintain safe access to all staff areas throughout the project.
As a well-established international company for transporting goods, the Northamptonshire warehouse is a vital hub of its UK operations. Due to the importance of the warehouse, work needed to be completed quickly and it was crucial that business was not interrupted. Non-invasive methods were selected so that the company could continue operating as normal while repair work was undertaken.
Off the ground
The contractor took on full project design and management of the remediation and handled all the steps necessary to locate, remove and reinstate all third-party services (gas, electricity etc.). A bespoke combination of non-invasive, computer-controlled grouting and resin injection was used to provide the necessary ground improvement and lift of the office building without causing business disruption.
Before commencing ground improvement and re-levelling works, the contractor discovered that the main gas pipe was running in front of the building and was posing safety risks. The project team accommodated this in the plans and managed the additional risks to ensure the subsidence rectification works could continue as planned.
Multiple injection ports needed to be installed through the concrete pads along the subsided sections of the building. Through these ports, the contractor inserted JOG high mobility cement grout under computer control. This enabled the team to lift the office building gradually and in a precisely controlled manner, moving the building back to its neutral position – all without causing business interruption
The contractor developed a customised plan to place the injection ports, to fit the structural elements of the building, ensuring it could safely continue to function as a workspace. A Teretek resin injection solution was then used to provide the necessary ground improvement, as well as raise and void fill the internal floor slab.
This approach also allowed for work to be tailored around busy periods, enabled successful management of noise levels and achieved project completion with minimal disruption to the day-to-day business.
The tenant said, “This was a difficult project with a strict time limit. We were extremely pleased that Mainmark managed to complete the project so efficiently and professionally, with absolutely no disruption to our day-to-day business operations. The team were helpful, knowledgeable and kept us informed every step of the way. We would absolutely recommend Mainmark’s services to other clients.”
The office was raised by as much as 57mm, and the ground was improved to the required specification, all in just 27 days. The client was able to continue to operate throughout the project, staff had safe access to all areas of the site and the repair work has provided a long-term solution for the ground issues, helping to ensure the on-going safety and efficiency of their warehouse operations.
Mainmark was chosen as the principal contractor thanks to its extensive experience working with large commercial warehouses. The company’s technologies offer non-invasive, cost-effective and time-efficient solutions. For this project, Mainmark used its JOG Computer-Controlled Grouting (JOG) technology – which offers the higher level of precision and control needed to lift such a substantial structure – and its proprietary Teretek resin injection, a non-invasive solution able to deliver both ground improvement and re-levelling.