Weak ground is the term used when the layers of soil beneath a structure become unstable and/or loose. As a result of becoming weak, the ground is no longer strong enough to support the weight of structures or floors, allowing them to subside. Significant signs of weak ground beneath structures include unlevel concrete floors, cracked floor tiles, and cracks on walls. It is greatly important that weak ground is corrected a soon as possible in order to prevent further damage.
What causes weak ground?
Weak ground can be caused by several different factors, both natural and man-made. For example, the ground beneath the structure may be comprised of sand or soil, as well as many other loose materials. In addition, man-made operations nearby may also loosen up the ground. These operations include drilling and digging activities.
Weak ground may be prevalent over both a large surface area and a small distinct location. Ground that may not be weak throughout will still cause problems regarding subsidence.
The various differing types of soil react differently to different conditions. For example, clay is highly susceptible to contraction when the rainfall levels are low, whilst rock soils are affected more by excavations and construction works. Soil is also softened by excess water.
Regardless of the cause, weak ground must be corrected and never ignored. Subsidence is the most common result of weak ground and must be corrected in order to stabilize the structure and protect the residents.
Likely causes for weak ground:
- A flooding of the ground
- An extensive period without rain allows the soil to become too dry- especially soils containing reactive clay
- Fillings that have been compacted poorly
- The removal of resources (liquid, gas or mineral) from the ground
- Earthquakes and seismic activities, often resulting in liquefaction
- Moisture can be removed from the ground by tree roots
- Vibrations caused by heavy road traffic or machineries. Excavation or drilling work taking place nearby.
- The lack of a footing system – more likely in very old buildings or in buildings that have undergone expansions or modifications
- Heavy loading
- A loss in strength of retaining walls
How can weak ground be corrected?
Geobear specialises in the stabilisation and improvement of soil and ground, the correction of foundations, the strengthening of weak ground and making it suitable in order to support existing structures, such as buildings, bridges, and roads.
The geo-polymer injections used by Geobear assure sub-grade stability under structures, such as buildings, concrete floors, driveways, roads, paved airport runways, bridge approach slabs, bridge abutments etc.
The solutions provided by Geobear are quick, precise, tidy, and, primarily, residents may also remain in the building undisturbed whilst the work is carried out.
What happens when my home is based on weak ground?
The techniques used by Geobear strengthen weak ground and create a strong foundation under structures of all sizes, ranging from large airport runways to residential homes, apartments and large offices. We have successfully performed thousands of re-levelling and ground strengthening projects around the world.
Our experienced engineers and technicians will establish the underpinning approach that will be required and create a plan that will be location specific to your property.
When the weak ground beneath a house is strengthened, the building and its sunken floors will be relevelled, whereupon any internal and external cracks on walls will usually close up. Most importantly, the damage to the structure will be corrected now and into the future.
The modern solutions we use to repair foundations are vastly more effective and efficient than the traditional concrete underpinning. Our services that utilise small resin injection holes do not just apply to the underpinning of concrete slab floors; we can also lift and relevel strip footings, ‘waffle-pod’ slabs, and raft slabs, whilst we can also fill in gaps on paths and driveways.
The most common method utilised by Geobear involves the injection of structural, expanding resins into the ground. This method is considered to be most effective in cohesive soils. The resins and hardeners are mixed together in the ground, whereupon they expand and compact the adjacent soils, increasing their load-bearing capacity.
Benefits of Geobear’s ground engineering solutions:
- Can be utilised at varying depths, even at a depth of 14 metres
- Can provide an increase of up to 500 percent in the bearing capacity of weak strata beneath structures
- Can be carried out at the same time as the lifting and re-levelling of a structure
- Can be used in the preparation of structures that are required to bear increased loads, e.g. when an addition will be placed to the building itself
- We will not make a mess: there will be no dust, water, etc, to clean up
- There is minimal disruption
- No further damage will be caused to the house or the landscaping
- With simple jobs, residents may remain in the building undisturbed
- Our techniques are non-invasive: no floors will be removed or ground excavated
- Our methods are much quicker than traditional methods. Simple, residential jobs are often completed in one day
- The products and techniques are environmentally friendly.