Desk Study and Preliminary Reconnaissance Flashcards
aims to foresee problems that may arise and
figure out possible ways to address them. Always a prerequisite for design
of engineering projects
site investigation
aims to identify problems that may arise in relation to the geology of a
site and the proposed structure, as well as possible solutions
geological investigation
data needed in geological investigation
soil and rock underlying the site
stratigraphy and structures
groundwater and mobility
extent of weathering
hazards
3 general phases of geological investigation
Desk study, preliminary reconnaissance, site exploration
Aims to gather and study all available literature and data related to the site
desk study
maps that show the geology of an area including data related to the rock units and distribution in the area, geologic structures, age
relationships of the rocks, as well as cross
section view of the map.
geologic maps (Mines and Geosciences Bureau)
Map of surface geology – shows data about material occurring at
ground surface including alluvium, mud, and other materials
drift edition geologic map
Map with no drift shown (like looking at ground if drift material are removed), only the SOLID geology underneath
solid edition geologic map
shows the relative ages of strata in a map and is usually found at the margin of the map
stratigraphic column
Scientific process to map geologic features in the area concerned and
create maps of it.
geologic mapping
Technology that allows easier management of spatial data.
GIS Geographic Information System
Allows determination of
precise location
GNSS Global Navigation Satellite System
Uses aircraft or satellites to measure
reflected and emitted radiation to
monitor physical characteristics of an
area or structures in an area.
remote sensing
uses emitted electromagnetic radiation
related to temperature of objects
IRLS Infrared Linscan
Pulses of energy are shot from
an aircraft, bounces off the ground, and is received by the aircraft again. This allows creation of photographs from recorded data. One of its advantages is that it is not affected by cloud cover
SLAR Side-looking airborne radar
uses laser in determining the distance or range of an object by computing the time for it to return
LiDAR Light detecting and ranging
can be used with a stereoscope to make a 3D ground surface model, which can then be used to make topographic maps.
aerial images
shows mainly the elevation data related to
the map. It uses contour lines to show which
areas are at the same altitude/elevation and
thus allows for visualization of flat areas vs
slope areas and how steep slopes are
Topographic Map (National Mapping and Resource Information Authority- NAMRIA)
show data and distribution of soil in an area
soil maps (Bureau of Soils and Water Management - BSWM)
shows the site’s susceptibility to
various hazards like earthquake or
liquefaction
hazard maps (HazardHunter PH)
based on the expected structure, one can estimate how much load will be transferred to the ground
possible loads
certain important structures have stricter rules in design and construction
importance
some structures can have deformation
like settlement of floor while some like factories that require precision (due to machine connections to each other) may have more stringent design considerations related to deformations.
tolerance to deformation
done to supplement the desk study and give a better report.
During this, a lot of information is noted related to the site as it is like soil
and rocks observed, vegetation, slopes, evidence of possible problems like
cracks on the ground or rocks, etc.
preliminary reconnaissance
