Previously we had a lot of productive input form the eng-tips respondents in relation to
thread256-266820, recently have engaged with our sewer and water provider and have obtained CCTV footage of the sewer line which shows extensive fracturing, damage and root intrusion in the sewer up line...
RON Good question and something I will raise today as a possibility.
It seams to be a consensus that the saturation of the soils is a major factor.
In line with that we spoke with a geo tech which had a similar event withe a water tower where a trench was dug, left open, filled withe water...
The major subsidence has slowed but has never stopped totaly.
as you can see in the prior post this increased when further influences were introduced in to the affected area.
At this point we have gone down 6m and found the water table there.
Interesting settlement movement escalated for about a week when we did the borehole over the approximate center of the affected area (2m from the dwelling), this was noticeable through movement indicators from with in the dwelling.
Msucog thanks for that we are trying to obtain ground water level monitoring as a new Marina was built within 1.5 km of the dwelling in the period of settlement.
Good Idea Oldestguy here is a URL to the soil types in our area of Australia.
Ron the period during which the initial major movement occurred was a period in which the area was surcharged with runoff.
Once this runoff was discontinued, settlement slowed but continued in a downward trend, with...
Unfortunately an old mine is not really a possibility we are 800ft from a major Bay.
But the site was once flood plain/reclaimed beach.
The Geology classification is Alluvial fan and Plain, with the soil types are a mix of Aquic Vertosols and Yellow and Grey Sodosols.
Thanks Ron,
We have ruled out trees as the major causative factor for the following reasons.
Treees around unaffected areas of the building ar of similar size and type.
Investigations have discounted vigorous tree root growth.
Surface area of settlement has remained considerably wetter...
We have a dwelling, which has experienced sudden settlement after 10-12 years of static performance of its foundations. In 2006 the dwelling (built in 95/96) and the surrounding ground (10-15 m in diameter) started to settle, the surface soils receded any where up to 100 mm and the foundations...