CVEN3203: ENGINEERING GEOLOGY QUIZ 2022
You have been asked to develop a preliminary geotechnical model of a site. The site has
previously been used as farmland.
The soil environment type and depth/thickness at the site is given in Table 1 and is based on
the last number in your student ID. The rock at the site is given in Table 2 and is based on the
second last number in your student ID. There is known to be at least one major geological
structure in your bedrock at your site, this is given in Table 3 and is based on your third last
number in your student ID.
Develop a geotechnical model for the site using the information above and your knowledge of
the materials and environments given. You should include at least one labelled cross section
with a discussion of why it looks like it does. Also provide a discussion of the soil and rock
materials and the geological structures that might reasonably be expected (point form may be
used and is preferred). You should consider all probable geological structures (not just the one
explicitly given in Table 3).
Table 1. Soil Environment Type and Thickness
Last
Number
SID
Approx.
Total
Thickness
(m)
Soil Environment Type
0 20 Marine sands overlying alluvial sands
1 18 5m alluvial sands; overlying a 3m basalt layer; overlying 10m alluvial
sands and gravels
2 10 Old glacial soils (no glacier remains)
3 16 Near the base of the slope of a steep sided narrow river valley
4 20 Floodplain (current river is now not near the site)
5 15 Alluvial soils in a narrow ‘V’ shaped valley
6 3 Residual soil
7 20 Aeolian sands (5m) overlying marine sands
8 20 Alluvial soils in a ‘U’ shaped valley
9 20 Floodplain (site is on the banks of the current river)
Table 2. Rock Environment Type/s
Second Last
Number
SID
Rock Environment Type
0 Schist
1 Marble
2 Slate
3 Conglomerate
4 Gabbro
5 Gneiss
6 Interbedded shale and quartz sandstone
7 Interbedded shale and limestone
8 Granite
9 Granodiorite
Table 3. Key geological structure known to be in the bedrock
Third Last
Number
SID
Defect/Geological Structure in Bedrock
0 Dyke
1 Normal fault
2 Reverse fault
3 Dyke
4 Normal fault
5 Reverse fault
6 Dyke
7 Normal fault
8 Reverse fault
9 Dyke
Example
SID = 3 1 2 4 5 6 3
Soil = (3) 16m; Near the base of the slope of a steep sided narrow river valley
Rock = (6) Interbedded shale and quartz sandstone
Structure/Defect = (5) Reverse fault