Highway Slope Manual

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key natural terrain and man-made geotechnical features, paying particular
attention to recording any signs of ground instability and geotechnical hazards
identified from the desk study, and confirm on site the nature and areal extent of
the key geotechnical features and geotechnical hazards identified, and signs of
seepage.
(c)
Based on the work of (a) and (b) above:
(i) assess the general topographical, geological, hydrological and
groundwater conditions along the existing and/or proposed highway
corridor(s)/alignment(s) and nearby, and refine the project study
boundaries if necessary,
(ii)
(iii)
carry out a Natural Terrain Hazard Review (NTHR) for the highway
project, in accordance with the guidelines issued by the Geotechnical
ngineering ffice, and
identify all existing man-made slope features and surface drainage
systems along the proposed corridor(s)/alignment(s) and nearby that could
affect or be affected by the proposed highway project.
(d)
Carry out a preliminary assessment of the site conditions and the identified
geotechnical hazards that could significantly impact on the cost and
programming of the project, in particular:
(i)
(ii)
(iii)
(iv)
(v)
assess the impacts of the potential hazards from natural terrain (i.e.
landslides and rock/boulder falls), determine the extent of the terrain that
needs to be further assessed and if possible, outline the likely mitigation
strategy required,
determine the need for formation and location of any new man-made slope
features,
determine if a Geotechnical Assessment (GA) is required or not, and if so,
prepare a brief for the GA with the objectives stated and the likely scope,
duration and cost provided,
determine if a Natural Terrain Hazard Assessment (NTHA) is required or
not and if so, prepare a brief with the objectives stated and the likely
scope, duration and cost provided, and
describe the objectives, assess the likely scope, duration and cost of
subsequent phases of ground investigation (G1) works, and prepare a
preliminary programme of the G1.
(e)
Based on the work in (d) above:
(i)
assess how the identified geotechnical features, hazards and constraints