Whether you are a developer of a large site or you have a few cracks in your bay window due to subsidence, you will need a site investigation, you may need us to study the past history of the site as well.
Samples of soil are extracted at predetermined positions at the site and pocket penetrometer readings taken at the same time, various other tests may then follow such as moisture content determination, some testing has to be done down inside the borehole which we are able to organise this for you.
We were involved in was the investigation of slope instability and the design of remedial works to stop movement of the house at the top of the slope. For the subsidence work, the measurements included the soil’s propensity to shrink when dried, its dryness profile and to what depth the dryness extends.
Another investigation was done in a hilly area which involved the investigation of water which appeared in a back garden, the water was then traced to a leaking sewer in the road at the front of the house.
If you are a developer, we would arrange for a desk study and a good check on all the chemicals that could be lurking below the surface
Moisture Content Results
At three locations the moisture content of the soil was measured at varying depths.
One location is well away from any trees and thus is called the control borehole location.
The location showing the least amount of moisture is the one closest to the offending tree, whilst the remaining borehole location provides moisture content results intermediate between the control borehole and the one closest to the tree.
One has to underpin down to a depth at which the moisture content directly below the property will be equal to the moisture content at that depth as found in the control borehole location.
One site investigation concerned this pool of water which appeared in a garden
Pocket Penetrometer Readings
At three locations soil samples were extracted by means of three boreholes.
Pocket Penetrometer readings were undertaken on the undisturbed soil to give a measure of the hardness of the soil, itself indicative of dryness.
The underpinning was taken down to a depth at which the Pocket Penetrometer readings in the borehole closest to the tree and a bit further away from the tree was equal to the Pocket Penetrometer reading at that depth as found in the control borehole location.