Void Filling

Mainmark offers a variety of solutions for filling underground voids and holes in order to stabilise strata in tunnels and to strengthen the foundations under buildings and other on-ground structures such as railways, roads and bridges.

What are voids?

‘Voids’ are essentially holes in the soil matrix that can appear naturally due to erosion and geological changes, or as a result of building, mining and other commercial or industrial digging activity. Voids can range from small to large holes and can appear as cracks and crevices, or in extreme cases, can be huge volume voids caused by a significant tunnel or pipeline collapse.

Voids underneath structures contain air and often water, which can then result in ground instability. If this happens, it is crucial void filling is commenced to prevent wider damage to the ground, structure and surrounding environment and to also prevent any potential hazards to the public.

This especially applies to man-made voids that have developed due to pipe abandonment. Underground voids can cause subsidence, soil destabilisation and water ingress that can increase the risk of residual fluids leaking into public areas and the ground collapsing. Because of these threats, it is imperative that void filling in abandoned pipelines is completed quickly, accurately and safely.

What causes voids?

Some of the most likely causes of voids are construction holes and excavation often present during mining, building and infrastructure works. Natural occurrences such as earthquakes, erosion and flooding can also be a major cause of holes and voids, and they can also develop over time due to leaks and weather eroding sub-soils underneath a structure. Other common causes include:

Land slippage

Abandoned tanks and pipelines

Mining operations

Poorly compacted fill or soil

Water ingress

How Mainmark can help

Mainmark specialises in void filling to re-support and prevent water ingress and erosion to critical infrastructure including railways, roads, highways, approach slabs, bridge approaches, bridge abutments, and airport runways. We offer underground void filling to stabilise strata in tunnels and to strengthen foundation works under a range of buildings such as residential, commercial and industrial facilities and other on-ground structures.

Our void filling solutions are non-invasive and time-efficient, allowing minimal downtime to operations and in many cases, occupancy can continue. We concentrate on achieving the fastest response time possible, choosing applications and materials with the least impact and allowing quick recovery times for our clients.

Each situation is assessed to determine the best course of action and material to use, taking into account hazardous environments.

Benefits of Mainmark’s methods to fill holes and voids

Adaptable and versatile – can be used under almost any structure or geotechnical situation

Suitable for a broad range of buildings and assets; from mass void fill, to pipe decommissioning and subgrade alternative

Time-efficient and controlled to provide ultimate safety

Soil stabilisation for bridge approaches and bridge abutments

Can be used as back-fill for retaining walls and wing walls

Efficient and economical void filling of trenches and manholes

Cost-effective, providing savings on materials and labour costs

Delivers a fast and controlled outcome

Strength and density characteristics can be tailored to meet each individual project

Lightweight materials reduce the pressure on retaining walls, bridge approaches, and slip planes


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