Page 24 - Demo

4.3 Ground Conditions Encountered
The ground conditions encountered in the low lying area at the base of the slope (the proposed building location) and on the slope are summarised in Tables 2 & 3 respectively:
Table 2: Ground Conditions in Low Lying Area
5
Stratum
Description
Depth to top of stratum from existing ground level
m
Thickness of Stratum
m
Typical CPT Tip Resistance
MPa
1
Dark brown sandy SILT (Topsoil/Fill)
-
0.7 to 1.2m
1 to 2
2
Brown & grey stiff sandy SILT (Alluvial)
0.7 to 1.2
0.2 to 0.5
2
3
Very loose to medium dense SAND (Alluvial)
0.8 to 1.2
1 to 3
1 to 12
4
Stiff to very stiff SILT (Hamilton Ash/Matua Subgroup Silt)
2 to 4
7 to 8
2 to 4
5
Medium dense to dense SAND (Matua Subgroup Sand)
10 to 11
-
8 to 12
The groundwater level was measured at 0.6 to 1m depth.
Table 3: Ground Conditions on Slope
Stratum
Description
Depth to top of stratum from existing ground level
m
Thickness of Stratum
m
Typical Shear Vane Reading
kPa
6
Stiff sandy SILT & Loose silty SAND with up to 700mm of topsoil (Younger Ash)
-
1.5 to 1.7
90
4
Dark brown and white and brown mottled, very stiff plastic SILT (Hamilton Ash/Matua Subgroup Silt)
1.5 to 1.7
3.5 +
120
The ground water level was not identified in the slope investigation.
6c Myrtle Drive, Omokoroa Project 533
O’Brien Geotech Ltd February 2017