Supporting a uK SucceSS Story: The impacT of - Research Councils ...

Strengthening foundations
through 3D geology
Around half of all cost and time over-runs on civil engineering
projects are caused by ‘unforeseen ground conditions’, partly
because we don’t understand enough about the ground’s
physical, mechanical and chemical properties, and the
processes acting on it. The 500-acre Olympic Park was no
exception; all the major development projects there involved
ground that engineers class as ‘difficult’. The land has been
affected by high groundwater levels, compressible soils – which
threaten foundations and underground constructions – and
contamination from pollutants like oil, petrol, tar, arsenic and
lead, which pose serious risks to water supplies and ultimately
human health if left untreated.
“3D mapping
helps
engineers
understand
potentially
difficult ground
conditions
by predicting
the properties
of rocks
and other
sub-surface
features.”
Traditionally, geological information has been displayed in two
dimensions – as maps supported by cross-sections. The Natural
Environment Research Council’s British Geological Survey (BGS)
has significantly increased the value of geological information
to the construction industry, by combining geographic
information with 3D modelling software to produce highresolution
geological models of the shallow sub-surface. This
3D mapping helps engineers understand potentially difficult
ground conditions by predicting the properties of rocks and
other sub-surface features they may encounter. Using 3D
models makes it easier to find drift-filled hollows, depressions in
the bedrock filled with unconsolidated materials like sands and
gravel which can cause major problems, such as uneven settling
of a building’s foundations. BGS also developed a prototype
screening tool for the Olympic Park, which will enable planners
to more efficiently evaluate possible sources of pollution and
the pathways – like flooding – by which it could find its way
into groundwater and become a risk to human health and the
environment.
Using the models, BGS created ‘intelligent’ map layers and
systems that support planning by clarifying the consequences
of different choices. This means difficult conditions can be
anticipated and mitigated, potentially significantly reducing the
time and costs of construction projects.
SECTION ONE : TECHNOLOGY 11