TM 5-852-4/AFM 88-19, Chap. 4
CHAPTER 3
SITE INVESTIGATIONS
site. Often, however, the opposite is true and site
3-1. General.
selection may involve hundreds or even thousands of
square miles of potential terrain. In such cases, remote
a. The site data needed for design of
sensing and geophysical techniques may provide the
foundations in cold regions include the same information
only economical approach. State-of-the-art reviews are
as would be required in temperate regions, but with
142
continued in publications by Ferrians and Hobson and
additional requirements imposed by the special climatic
165
Linell and Johnston . Use of conventional aerial
conditions. Also the remoteness of the site often
155
photographic techniques for terrain and site investigation
imposes additional requirements . Subject to design
in arctic and subarctic areas began in the late 1940's and
policies, general criteria, cost limitations and the
62
the results were reported by Frost . The U.S. Army
constantly changing state-of-the-art, site information
Corps of Engineers has included summaries of these
needed for design of foundations in cold regions may be
techniques in two Engineering Manuals.
Aerial
summarized as follows:
photography and photo interpretation are invaluable in
Climate (general and local).
obtaining much of the needed site information and
Physiography and geology, including topography
should be employed routinely as part of design studies.
and surface cover.
Information obtained by aerial photography should be
Subsurface conditions.
tied in with coordinated ground investigations. The
Thermal regime.
ground studies will provide reference data and accuracy
Hydrology and drainage.
checks of the aerially obtained data and should extend
Materials of construction.
this information in the detail necessary for actual design.
Transportation facilities and access.
The accelerating development of northern North America
Construction cost factors.
in recent years has greatly spurred practical use of these
b. Availability of labor, construction equipment
techniques, particularly in connection with investigations
and supplies. Must of the information needed for
172
for several pipelines .
foundation design must be obtained as a part of the
b. Color and infrared photography, and radar
over-all facility design. However, some elements of
and other special forms of sensing techniques may also
needed information pertain specifically to foundations.
be employed. Rinker and Frost have recently discussed
c. By giving adequate attention to subsurface
the application of various type of remote sensing to
conditions during the site selection stage, foundation
182
151
environmental studies in the Arctic . Haugen et al.
design problems and facility costs can often be greatly
141
and Ferrians
are currently investigating potentials for
reduced. When facilities can be sited on deposits of
satellite acquisition of data under the Earth Resources
deep, free-draining, non-frost-susceptible granular
Technology Satellite (ERTS) program, obtaining
materials, design, construction, maintenance, and
information on such surface details as vegetation, snow
operational problems are all minimized.
and ice cover, ground temperatures, geomorphic and
d. When a facility such as a power
other evidences of permafrost, stream levels,
transmission line or long pipeline covers an extended
sedimentation
patterns,
and
forest
fires.
area, not only may a variety of foundation conditions be
Electromagnetic sensing systems, both airborne and
encountered but also a considerable range of ground
surface operated, have been shown capable of
temperatures and permafrost conditions. In such cases
distinguishing with depth materials such as soils, ice and
it 'will be uneconomical to develop an individual design
142,144,147
, to
rock having different electrical properties,
specifically for each structure or portion of the facility.
depths of 15 meters or more in frozen ground. Although
Instead, the terrain may be divided into areas of like
not yet routinely used, such equipment is in a state of
foundation conditions, and standard designs prepared
147
and
rapid and continuing development.
Garg
which will be suitable over each of these areas. Also, a
152
have reported that both resistivity and
Hunter
number of standard designs may be prepared to cover
refraction types of conventional geophysical systems
the range of conditions, the particular design for each
84
have utility in permafrost areas, and Roethlisberger has
facility element to be field-selected in accordance with
summarized the state-of-the-art of seismic exploration in
the conditions actually encountered.
cold regions. Development of acoustic reflection type
sounding equipment for use in permafrost areas is in a
3-2. Remote sensing and geophysical investigation.
149.163
and
very early state of development. Greene
a. Aerial
investigation
techniques
are
162,163
have concluded that infrared sensing
LeSchack
especially valuable during the selection of the site
techniques can provide useful infor-
location itself.
At times communications or other
requirements may closely dictate the choice of the facility
3-1
Previous Page
