The application of JOG Computer-Controlled Grouting

Holy Trinity Church – subsided by: 26mm

The annex to this historic Anglican Church had subsided by up to 26mm, causing it to separate from the main building. Mainmark’s JOG technology allowed for a more controlled and precise lift, which is critical for delicate buildings. Crucially, the majority of the equipment and grout was located away from the injection area and was delivered to the injection points via a sequence of hoses, avoiding excessive intrusion to the grounds.

A total of five injection points were used to lift the structure at its lowest point, closing the cracks and improving ground conditions. The work was completed within a two-day period.

Residential Property – subsided by: 82mm

A two-storey brick house was sloping, leading to uneven subsidence by as much as 82mm in the lowest position. Access to the house was via a shared driveway that was narrow and sloping, meaning Mainmark had to configure all its equipment within a small lorry and then use that as a work platform to make the most of the limited space available.

Mainmark’s JOG method was the least disruptive option available to the homeowner because it did not require any structural demolition, removal or reinstatement of landscaping. Using JOG, Mainmark lifted the 64m2 home by as much as 82mm in just five days.

Coffee Production Facility – subsided by: 120mm

The ground underneath a South London business unit had weakened, resulting in the integrity of the building being compromised.

Multiple injection ports were installed through the concrete foundation and structural pads along the subsided section of the building, through which the JOG cementitious grout was introduced under computer control. The spacing and placement of the injection ports were tailored to accommodate the structural elements of the foundation, while the grout was mixed and pumped from just outside the unit’s main entrance.

The facility remained in operation during the entire re-levelling process and ground improvement was provided by Teretek® injection at various depths. Despite limited space the structure was successfully re-levelled by 138mm within 11 days while leaving the neighbouring property unaffected.

Ultima Furniture – subsided by: 353mm

A kitchen manufacturer recently purchased a large 3,700m2 warehouse in Pontefract which was built on 20m of made ground in an area that had a history of mining activity.

The facility was experiencing building subsidence and subsequently tilted severely towards the rear.

During the preceding 10-15 years, the building had subsided by 353mm below its original level, making it unsafe for workers.

The building owner was considering two main solutions: demolition and rebuild; or ground remediation to re-level the building and help arrest the subsidence.

Mainmark’s JOG technology was chosen (in combination with Mainmark’s Teretek resin injection solution) as this would allow for the desired outcome with minimal intrusion to the building. This method also allowed a portion of the building to be used by the client during the lifting process.

The project was completed in a time-efficient and cost-effective manner, well within agreed budgets and timeframes, achieving a maximum lift of 325mm.