Post on 28-Mar-2015
5th Intensive Course on Soil Micromorphology
Naples 2001
12th - 14th September
Image Analysis
Lecture 11
Engineering Applications of Soil
Micromorphology/ Microfabric Analysis
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Engineering Applications
Quantitative Methods
•Examples of Intensity Gradient Analysis
•New methods for porosity analysis
Dynamic Studies
Applications to a Palaeosol of coast of Hong Kong
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Intensity Gradient/Orientation Analysis
There is evidence to show particles do align perpendicular to principal stress direction.
BUT
Orientation is far from complete.
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
How does orientation vary within a sample?
Over 350 separate estimates of orientation were made on this sample.
The location of each image is indicated by the + while the length of the line and direction indicate the degree of anisotropy and the preferred direction respectively.
In this sample the microfabric is very uniform
These results were obtained with a fully automatic system
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Other samples are less uniform
Uniform in places, but shear discontinuities evident
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Microfabric changes on shearing
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Detail across a failure zone
At the edges of the failure zone, the Index of Anisotropy is less than outside region, but there is a sharp change in angle on either side - suggesting a kink zone failure.
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
New developments in Porosity Studies
Original Image Binary Version of Restored Image
Flow of fluids is high influenced by path length
Which is shortest path across image?
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Path highlighted is shortest continuous path
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Original Image Binary Version of Restored Image
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Slight differences are apparent if 4-point or 8-point connectivity is assumed
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Problem with 8-point connectivity
Are voids or particles continuous at these points?
No problem with 4-point connectivity
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Dynamic Studies: - deforming soils in SEM
Shear Box used in 1973 study
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
VIDEO of dynamic deformation
School of Environmental Sciences
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
A Study of Hong Kong Marine Soils
Simplified Sequence of Deposition
During last inter-glacial
deposition of unit M2
When sea level fell, surface layer was exposed to desiccation, oxidation, pedogenesis, etc.
In the Holocene, the sea probably covered the area around 6000 - 8000 years ago
deposition of unit M1
M1
T1
M2
~10m
Press Return to continue
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Classification according to Yim (1994)
School of
Environmental Sciences
Freeze-dried example of recent Marine Soil (0.5m depth)
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Bintang Bolon
The Gambia
School of
Environmental Sciences
Open fabric preserved in Hong Kong Holocene deposit
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
School of
Environmental Sciences
Fabric in M1 unit beneath Trial Embankment showing flow patterns around silt sized grains
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
School of
Environmental Sciences
Aggregates of stacks of kaolinite particles showing evidence of cementation: Kwai Chung Container Terminal
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
School of
Environmental Sciences
Deposition of amorphous material at base of M1 unit borehole T8.
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
School of
Environmental Sciences
Schematic showing different changes in fabric from consolidation.
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
School of
Environmental Sciences
Sand grains filling crack in palaeo-desiccated layer
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
School of
Environmental Sciences
Pyrite within Hong Kong Marine Soil
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
School of
Environmental Sciences
Sulphate reducing bacteria and framboid of pyrite in recent marine clay
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Bintang Bolon: The Gambia
School of
Environmental Sciences
Pyrite within a decaying root of mangrove: The pyrite appears to form away from the bacteria
Bintang Bolon: The Gambia
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Pyrite in Chek Lap Kok marine clay also show concentration of nickel. Image analysis shows varying degrees of oxidation within the pyrite.
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
School of
Environmental Sciences
Formation of halite crytals
Optical Micrograph showing halite crystal 100 m + in size in desiccation crack
Small halite crystals (1 - 5 m in size on side of root salt tolerant Mangrove
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
School of
Environmental Sciences
Optical Micrograph of halite crystal and corresponding trace in BSE image
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.
Procedure of segmentation is know as Mineral-Segmentation
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 9: Multi-Spectral Methods
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 9: Multi-Spectral Methods
Index of Anisotropy
outside aggregate: 0.229
inside aggregate: 0.374
In both cases the predominant orientation is nearly vertical.
Vertical direction in field.
• Image acquisition
•Image Processing• Image enhancement • Filtering• Image reconstruction
• Image Analysis
•Quantitative analysis
• Interpretation
The four I’s of Microfabric Analysis
5th Intensive Course on Soil Micromorphology - Naples 2001Image Analysis - Lecture 11: Engineering Applications.