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

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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, Page 2-18 FINAL - Rev. 0 January 20, 2010
Northern Gateway Pipelines Inc. Section 3.10: Site Plans and Technical Data Table of Contents • An additional 52 lines (totalling 20.2 km plan length) surveyed between June and August 2006. The collective set of lines were located to provide a grid overlay of the entire site, including the main tank lot, the impoundment reservoir area, the main terminal facilities area, and the foreshore area. The primary geotechnical considerations that will be addressed during detailed design of the uplands portion of the Kitimat Terminal include: • Foundation and supports for the tanks and other infrastructure; • Rock falls and rock toppling failures on existing rock slopes and in excavated cut slopes; • Detection and disposal of potential acid generating rock from excavations; • Stock piling of excavated top soil and organic material; • Maximize reuse of excavated materials as engineered fills; • Disposal of excess overburden materials; • Differential settlements under the oil and condensate tanks; • Potential instability of the marine clays; • Diversion, collection, and disposal of storm water and surface runoff water during and after construction; • Road design for appropriate vehicle traffic; and, • The potential effects of seismic activity at the terminal, particularly on the oil and condensate tanks and piping. 2.6.3 Geotechnical Data 2.6.3.1 Bedrock The site for the Kitimat Terminal is underlain by bedrock throughout the uplands area and inter-tidal zone of the berth structures. The bedrock can be characterized as strong to very strong igneous and metamorphic rock which consists mainly of gneiss (metamorphic rock) and quartz diorite (igneous rock) both cross cut by felsic dykes (igneous intrusive rock). At the proposed site, the depth to bedrock ranges from surface exposure to approximately 25 metres. A field review of bedrock outcrops indicated that the bedrock can be locally fractured and has other structural features which may cause potential planes of weakness. The stability and bearing capacity of the bedrock is largely determined by these discontinuities within the rock mass and can vary greatly over relatively short distances. Unconfined compressive tests were conducted on two rock core samples. The first sample broke at a strength level of 134 MPa. The type of failure indicated the sample consisted of intact homogenous rock and is classified as “very strong”. The second test broke at a much lower strength of 71 MPa indicating the presence of a micro crack or similar plane of weakness. This second core sample is classified as “strong” rock. January 20, 2010 FINAL - Rev. 0 Page 2-19
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Section 3.10: Site Plans and Technical Data - Rick Neufeld Comments

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