James O’Grady, Business Development Manager at Mainmark Ground Engineering offers his advice on spotting signs of subsidence and ways to minimise downtime when addressing them.
Renewal and maintenance are crucial to ensure the efficient operation and longevity of supply chain management facilities such as warehouses, factories, delivery docks and busy transport hubs. The 24/7 nature of many facilities can also place huge strain on the facility’s foundations, particularly those that rely on large haulage vehicles such as port terminals and warehouse delivery docks.
Smooth and efficient working environments are crucial to business operations that continuously receive and despatch goods and materials. If the ground beneath the facility becomes unstable, ground engineering solutions and technologies can help.
Cracking or uneven concrete slabs in warehouse floors, driveways and delivery docks are often attributed to ground subsidence. Subsidence can occur when the soil beneath the slab compresses under pressure, or swells and contracts due to changes in the ground’s moisture level. Left untreated, ground subsidence can render driveways unsafe, dockyards unusable, and destabilise machinery.
Subsidence also compromises the safety of workers by creating trip and fall hazards, slippery surfaces due to water ponding, and unstable shelving, walkways, gantries, elevated work platforms and ladders.
Mainmark Ground Engineering is an industry leader in ground engineering solutions for warehouse and transport logistics sites, having undertaken remediation work for major logistics facilities across Australia, New Zealand and the wider Asia Pacific region using solutions that can quickly arrest and resolve the underlying ground subsidence issues impacting a structure. With the ground engineering specialist’s innovative application methods and solutions, works can often be conducted unobtrusively and cost effectively, with minimal disruption to daily operations.
How to identify subsidence
The sooner subsidence is identified, the sooner remediation can begin. Re-levelling a structure or strengthening the ground beneath or around infrastructure can help to extend its lifespan.
Signs of subsidence include:
- Cracked or uneven floors;
- sinking concrete slabs;
- sloping floors;
- un-level shelving;
- outer edges of concrete floor standing higher than the midline, also known as ‘dishing’.
Transport hubs and delivery yards that rely on frequent and seamless heavy vehicle use can also, over time, experience undulation of the ground which can worsen due to voids that have formed beneath the foundations.
Injectable ground solutions vs traditional underpinning
Traditional underpinning methods such as concrete underpinning, piling and jet grouting all require extensive excavation around the structure which often requires operations to cease completely, sometimes taking weeks for the works to be completed.
Mainmark has extensive experience in identifying and creating bespoke solutions to complex ground engineering issues, using non-invasive technologies for raising, re-levelling and re-supporting sunken structures on or in the ground including vast concrete floor and driveway areas within warehouse and logistics environments.
Non-invasive technologies, such as Teretek® and JOG Computer-Controlled Grouting, are advanced alternatives to more traditional and costly processes.
Teretek® is a unique two-in-one, engineered resin injection solution that delivers both ground improvement and re-levelling, whilst increasing ground bearing capacity and filling voids.
JOG Computer-Controlled Grouting is a process of multi-point, cementitious levelling of large, complex structures by computer-controlled equipment. This precise solution is controlled to the millimetre so there is no undue stress on any part of the structure as it is raised back to level.
Mainmark successfully corrected slab dishing at a large transport yard
When a full-service wharf logistics business that operates round the clock, receiving and delivering large shipping containers for the Port of Brisbane, identified issues with its concrete hardstand, the business turned to Mainmark for help.
The large concrete hardstand is used for loading, unloading and storing 20ft and 40ft containers, and functions as a traffic corridor for heavy vehicles. The concrete slabs were originally laid on compacted ground several years ago, but the area had since become affected by serious subsidence. The issue had been exacerbated by additional water ingress that had infiltrated the soil substrate beneath the slab. Settlement at the outer edges of the hardstand were dishing, causing water to pool in the centre, further compounding the problem.
Mainmark was able to re-level the hardstand using JOG Computer-Controlled Grouting, enabling a level correction without the use of hydraulic jacks or temporary lifting platforms. The process is extremely precise with the cementitious solution achieving a controlled, pinpoint result in a remarkably short timeframe, therefore minimising operational downtime.
For more information about Mainmark’s innovative ground engineering solutions that are suitable for factory, warehousing and logistics environments, contact Mainmark on 1800 623 312 in Australia, 0800 873 835 in NZ, or visit www.mainmark.com.