Boring logs, which identify:
Design frost depth, if applicable.
Sample number and sampling method.
Removal or treatment of contaminated soil.
Other pertinent data deemed necessary by the geotech-
Discussion of potential for consolidation and/or
nical engineer for design recommendations, such as:
differential settlements of substrata, with design
Unconfined compressive strength.
recommendations for total settlement and maximum
Standard penetration test values.
angular distortion.
Subgrade modulus.
Use and treatment of in-situ materials for use as
Location of water table.
engineered fill.
Water tests for condition of groundwater.
Recommendations for future sampling and testing.
Location and classification of rock.
Recommendations for pavement designs, including
Location of obstructions.
base and sub-base thickness and subdrains.
Atterberg tests.
Recommendations for foundation and subdrainage,
Compaction tests.
including appropriate details.
Consolidation tests.
Triaxial compression test.
Discussion of soil resistivity values.
Chemical test (pH) of the soil.
Discussion of radon values and recommendation for
mitigating measures, if required.
Engineering Recommendations. Engineering
Geologic Hazard Report
recommendations based on borings and laboratory testing
should be provided for the following:
A geologic hazard report shall be prepared for all new
Recommendations for foundation design, with discussion
building construction in Regions of Low, Moderate and
of alternate solutions, if applicable, include:
High seismicity, except for structures located in regions of
Low seismicity designed to the Life Safety Performance
Allowable soil bearing values.
Level. Geologic hazard reports are not required for minor
Feasible deep foundation types and allowable capac-
or relatively unimportant facilities for which earthquake
ities, where applicable, including allowable tension
damage would not pose a significant risk to either life or
(pull-out) and lateral subgrade modulus.
property.
Feasibility of slab on grade versus structurally
supported floor construction, including recommended
Required Investigation. When required by the project
bearing capacities and recommended subgrade
scope, a geologic hazard investigation which addresses the
modulus (k).
hazards indicated below should be performed. Whenever
possible, a preliminary investigation should be performed
Discussion of evidence of expansive soils and recom-
in the planning stage of siting a facility, to provide
mended solutions.
reasonable assurance that geologic hazards do not
Lateral earth design pressures on retaining walls or
preclude construction at a site. During a later stage of
basement walls, including dynamic pressures.
350 F A C I L I T I E S S T A N D A R D S
FOR THE
PUBLIC
BUILDINGS
SERVICE
A.5 Surveys and Geotechnical Reports Geologic Hazard Report
Revised March 2005 PBS-P100
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