Section 3.10: Site Plans and Technical Data - Rick Neufeld Comments

Northern Gateway Pipelines Inc.
Section 3.10: Site Plans and Technical Data
Table of Contents
Of particular importance for the marine structure foundation design is the stability of the steep underwater
rock slopes, as well as the stability of the clay and rock slopes along the foreshore above the marine
structures. Oriented rock core techniques and geological mapping of the rock structure will be used to
evaluate the nature and extent of joints and faults in the rock to help assess the rock stability. The results
of this investigation will dictate the possible structure types and construction methods required to mitigate
the risk of rock slope failure.
2.6.2 Uplands Geotechnical Investigations
Although there has been no marine geotechnical investigations conducted for the berth structures to date,
some useful information can be obtained from a two-phase preliminary-level geotechnical investigation
that was completed for the uplands portion of the terminal site (Reference 5, 6). This study included
LiDAR elevation data, boreholes, and geophysical data and was meant to characterize the geological
conditions of the uplands site. The goal was to provide preliminary geotechnical assessments and
recommendations relative to the site grading and foundation design options for the terminal tank farm and
other upland facilities.
The uplands geotechnical investigation included:
• A ground-based survey carried out at the site during September and October of 2005 under the
direction of AMEC. This survey was done to establish a project control network and provide
geophysical line profile data for concurrent geophysical surveying;
• Additional ground-based surveys in July and August of 2006, including 52 hand-cut survey lines
totalling approximately 20.2 km in plan length. The line locations were selected to provide a grid of
data across the entire site, including the main tank lot, the impoundment reservoir area, the main
terminal facilities area, and the foreshore area;
• A LiDAR survey completed in September of 2005. The survey was helicopter based and was carried
out at planned flight altitudes of between 100 metres and 250 metres above ground level. The original
LiDAR data did not correlate well with the ground-based surveys therefore the LiDAR was
subsequently re-flown in 2006. The second set of LiDAR data aligned very well with the groundbased
surveys;
• Seven drill holes and nine test pits completed at the site between October and November of 2005. The
holes were drilled to between 1.5 metres and 3.0 metres into the underlying bedrock, resulting in total
borehole depths between 10.2 metres and 21.8 metres. The test pits were completed to depths ranging
between 1.0 metres and 7.5 metres depth;
• An additional 17 drill holes completed on the site between July and August 2006. Boreholes were
drilled 5.0 metres into bedrock, resulting in total borehole depths between 5.2 metres and
33.2 metres. Four of the drill holes were drilled using diamond drilling methods to investigate
bedrock conditions. Final depths for these holes ranged between 42 metres and 97.2 metres;
• Initially, 11 geophysics survey lines (totalling 11.6 km in plan length) surveyed using seismic
refraction geophysical methods to estimate the depth of overburden soils and to provide a profile of
the underlying bedrock surface along the lines; and,
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