How can you prepare for a sinkhole?

Answer 1

In areas where sinkholes are common there are a number of engineering solutions that can make structures more resistant to the potential effects of sinkholes.

Foundation improvement:

A new building will likely be constructed on a reinforced concrete raft foundation which would be able to span any sinkhole likely to develop below it. Larger structure may also used piled foundations (piles are long thin foundation elements that extend into the ground and allow the building load to be spread onto deeper stronger layers) designed to bear on strata below the surface that are known to be competent (i.e. not likely to fail) based on data from a site investigation.

Existing building may undergo "underpinning" which is a process where the existing building is retrofitted with pile foundations to improve stability in the event that sinkhole subsidence may occur.

Ground improvement:

Where sinkholes form as the result of the collapse of subsurface voids (for example old abandoned mine workings) then a process known as "grouting" may be used. Depending on the exact nature of the underground voids, holes will be drilled and a mixture of cement grout and gravel will be emplaced in the voids. This material is viscous and the engineers are able to create cones within the void space that once set, act to support the roof of the void, stabilising it and so stopping the roof collapse from occurring in the first place. Smaller voids may be totally filled with the gravel / grout mix to stabilise them.

Signs that sinkhole or other subsidence may be occurring:

As a ordinary member of the public, there are some signs that you may wish to look out for that might warn you that a sinkhole is developing or that you are living in an area that they may occur:

Ponding of water in an area where this previously did not happen - this suggests that the ground surface is sinking and may indicate that a sinkhole is forming below this spot.

Other changes in drainage patterns - a spring drying up or the sudden loss of water from a stream or river, may also indicate subsurface movement.

A local history of mining - if mining has occurred in your local area (maybe consult local maps or historical maps for signs of old shafts, or the locations of collieries or other mines) then there is the potential for instability.

Cracking or changes in alignment - masonry structures are very sensitive to changes in ground level, especially if this occurs to different degrees along the length of a structure (known as differential settlement) and which causes tilting. This in turn can lead to the formation of cracks. If you notice cracks in your house and they appear to be getting larger, it would be sensible to consult a chartered surveyor / structural engineer to undertake an inspection. However most masonry structures undergo some degree of slight cracking and this is not necessarily a cause for alarm!

What to do as a member of the public:

It is important to realise that sinkhole subsidence can be a very sudden occurrence with very little prior warning, the best way to prepare for a sinkhole is to employ a qualified engineer to remediate (fix) the problem before it reaches the surface! If in doubt consult the authorities / a professional engineer or geologist!

Answer 2

To prepare for a sinkhole, you can consult with a geologist to assess the risk in your area, maintain a healthy landscape with proper drainage to prevent erosion, and monitor any signs of ground settling or cracks that may indicate potential sinkhole formation. Additionally, consider having appropriate insurance coverage to protect your property in case of a sinkhole event.