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GIS Applications in Geotechnical (Soils) & Environmental
Engineering
Hawaii Pacific GIS Conference 2012 March 7, 2012
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Elise Leroux, Associate
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Geotechnical Consulting
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Slope stability study, near
Hāwī, Big Island
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Dam safety study, Kaua‛i
Geotechnical
investigation, Mauna
Lani, Big Island
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Compaction testing
on new waterline,
Moloka‛i
Mass grading for
housing at Ford
Island, O‛ahu
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Pile driving, Arizona
Memorial Visitor Center,
Pearl Harbor
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Geotechnical test pit for
Waimānalo Stream restoration
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What does this have to do with GIS?
Maps for Project Reports
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Location maps
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Geologic mapping
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Geologic mapping; differing
soils
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Historic geologic mapping
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Soil mapping
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Maps for Field Investigations
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Mapping sample locations – Step 1: layout points based on plan
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Mapping sample locations – Step 2: georeference plan
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Mapping sample locations – Step 3: remove plan
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Mapping sample locations – Step 4: add coordinates; grid
19 Example on large project
Historical Landforms and Planned Construction
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Map depicting former sump and boring locations
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Location
23 Georeference historical map
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38 Georeference historical photo
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Approximate the boundary based on historical maps & photos
42 Overlay site plan
Map book for road design
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Hydrology and hydrogeology
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Sheet piling,
Middle Street,
Honolulu
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Slope stabilization,
Nu‛uanu Stream,
O‛ahu
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Stormwater Runoff and GIS
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Calculating runoff to plan for
construction
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Surface water hydraulic analysis
Problem: stormwater washing out road during construction
Who is responsible for extra costs?
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Analysis procedure
Map problem areas
Map contributing drainage area(s) for each
Calculate design flow for each drainage area
Calculate design drainage for each problem area
Based on road linear foot
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Analysis continued
Calculate flows from actual storm
Compare with design flows (design was greater)
Estimate necessary size of diversion structures
Compare with original design
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Environmental Consulting
Environmental
sampling at
Kalaeloa, O‛ahu
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Environmental Investigations
Direct push
drilling for
groundwater
contamination
investigation,
Waikīkī
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Environmental
soil sampling,
Hanua Street,
Kapolei
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DETERMINING SAMPLE LOCATIONS
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Mapping sample locations 66
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Environmental Permitting
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Excavation that
will require
dewatering,
Honolulu Zoo,
Waikīkī
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Environmental Permitting
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Environmental Permitting
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Environmental Planning
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ROCKFALLS
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Boulder problem
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From whose land did it come?
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Step 1: Map possible source based on contours
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Georeference historical image
Georeferencing is imprecise
Nature of aerial imagery from low-flying aircraft
Distortion away from flightline
Vast changes in landscape & development
Few tie-points
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This one is better due to increased tie-points
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Multiple historical images may help
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Landowners
Analysis
Boulder came from state land
Unclear if it was from land previously “worked”
Recommend field investigation
May be possible to determine exact location
Can assess future hazards
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IMAGES FOR COMMUNITY MEETINGS
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Rock slide investigation,
Koko Crater, O‛ahu
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Boulder investigation,
Koko Crater, O‛ahu
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Images for community presentations
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Boulder locations & elevations
Koko Crater Rock Fall Investigation,
April 2009
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Rock slide probable path
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Rock slide probable path
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Rock slide probable path
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QUESTIONS?
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Mahalo!
Contact info:
Elise Leroux
tel. (808) 484-5366
Masa Fujioka & Associates
98-021 Kamehameha Hwy #337
Aiea, HI 06701
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