LANDSCAPES, ROCKS AND TUNNELS: PRACTICAL ......PRACTICAL CONSIDERATIONS IN TRANSPORT GEOGRAPHY Key...
Transcript of LANDSCAPES, ROCKS AND TUNNELS: PRACTICAL ......PRACTICAL CONSIDERATIONS IN TRANSPORT GEOGRAPHY Key...
198 199TOPIC THREE: PLANNING, DESIGNING AND BUILDING A RAILWAY FASTTRACKING THE FUTURE | SECONDARY EDITION NOVEMBER 2016
Topic Three:
Planning
, desig
ning
and b
uilding
a railway
LANDSCAPES, ROCKS AND TUNNELS: PRACTICAL CONSIDERATIONS IN TRANSPORT GEOGRAPHY
Key Learning Area
Unit or lesson title and main focus questions Most appropriate level and suggested number of lessons
Geography Landscapes, rocks and tunnels: Practical considerations in transport geography
What landscapes and rock types does the railway cross, both underground and over ground?
Stage 5
1–3 lessons
Teacher briefingSydney Metro Northwest Environmental Impact Statement 2, provides easily accessed geological data on the construction of the Sydney Metro Northwest tunnels. This activity provides Stage 5 students with the opportunity to explore the basic ideas of geotechnics and some of the geological issues that need to be solved when building a tunnel.
Focus questions: � Which part of Sydney Metro Northwest is underground?
� What rock types does it pass through?
� What technical problems might these rock types present to engineers and how will they solve these?
� Do the above ground sections of the rail line present the same or different challenges?
Requirements for these lessons � Internet connected computers
� Google Earth or Google Maps
� Activity sheet 1 – Map of Epping-Rouse Hill
� Graph paper.
Key terms and vocabularyGeotechnics, cross-section, geological long section.
FAST FACTS
ON THE WEB
DOWNLOAD
INFOi
Web linksSubmissions Report Stage 1, Chapter 2http://www.sydneymetro.info/documents
Sydney Metro Northwest Environmental Impact Statement 2, Appendix C – Geological long section(This version only includes the cross-sections, with different page orientation)
http://www.sydneymetro.info/sites/default/files/29_Appendix_C_-_Geological_Long_Section.pdf%3Fext%3D.pdf
Sydney Metro Northwest Environmental Impact Statement 1, Appendix A – Geological long sectionhttp://www.sydneymetro.info/sites/default/files/26_Appendix_A_-_DGRs__CoA___SoC.pdf%3Fext%3D.pdf
Sydney Metro Northwest Environmental Impact Statement 2, Project Description – Operations Part 1, Chapter 6http://www.sydneymetro.info/sites/default/files/07_Ch_6_Project_Description_-_Operation_-_Part_1_of_2.pdf%3Fext%3D.pdf
Sydney geological maphttp://www.resources.nsw.gov.au/__data/assets/image/0005/287204/Sydney_500k.jpg
Any topographic map of the area, or SIX Viewerhttps://six.nsw.gov.au/wps/portal
Background informationStudents explore geological problems engineers have solved when planning Sydney Metro Northwest. The main rock type in this area is Hawkesbury sandstone that can be easily tunnelled, but may require support. Tunnels are unlike any other civil engineering structures. In buildings or bridges the construction materials have defined and testable properties, whereas this is not the case with tunnelling.
No matter how much of the ground is tested in preliminary site investigations, usually through borehole cores tested in the laboratory, only a small fraction of the tunnel construction area can be tested. Therefore, it is up to engineers to determine the relevant ground conditions and the effects of layering, fissures and discontinuities. Much of this assessment is based on geological and geographic judgment and experience.
200 201TOPIC THREE: PLANNING, DESIGNING AND BUILDING A RAILWAY FASTTRACKING THE FUTURE | SECONDARY EDITION NOVEMBER 2016
Topic Three:
Planning
, desig
ning
and b
uilding
a railway
Syllabus links
Geography K-10Geography Stage 5 - Changing places
- the management and planning of Australia’s urban future.
Environmental change and management
- human-induced environmental changes across a range of scales
- the causes, extent and consequences of the environmental change
- management of the environmental change.
(GE5-2) explains the processes and influences that form and transform places and environments
(GE5-7) acquires and processes geographical information by selecting and using appropriate and relevant geographical tools for inquiry
(GE5-8) communicates geographical information to a range of audiences using a variety of strategies.
Learning experiencesStep 1 – Class discussionDisplay Sydney Metro Northwest Environmental Impact Statement 1, Appendix A – Geological long section http://www.sydneymetro.info/sites/default/files/29_Appendix_C_-_Geological_Long_Section.pdf%3Fext%3D.pdf on the interactive whiteboard, or distribute the pdf for students to view on their own computers.
The teacher explains that most geographical studies create and analyse maps that ‘look down’ on the Earth. However, engineers working on Sydney Metro Northwest examine ‘side-on’ maps to see where the rail line will be elevated, where it will dip underground, and which rock types it will pass through.
A passage describing the planned tunnels from the Sydney Metro Northwest Environmental Impact Statement 2 OverviewThe tunnels would have a maximum vertical grade of 4.1% and have been designed with an appropriate curvature to accommodate an operating speed of 100 km per hour. The vertical gradient of the tunnels is influenced by the topography, geological constraints, presence of watercourses and the alignment has been designed to provide sufficient clearance to existing and proposed building basement levels (for example below Castle Hill town centre). The tunnel crown (top of the tunnel) would be located at its shallowest point approximately three metres below ground surface and at its deepest point approximately 58 m below ground surface. On average the tunnels would be more typically in the 20–25 m depth range and tunnel depth would tend to be at its shallowest at station locations and at the northern tunnel portal.
2-7A
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CAST
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CASTLE HILL STATION(CUT & COVER)
CHERRYBROOK STATION(CUT & COVER OR OPEN STATION)
RL 179.00mAHDOffset 36.43m
R01-BH03
40.96
RL 142.00mAHDOffset 14.06m
R01-BH04
DHAm90.531 LRm30.41- tesffO
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RL 140.74mAHDOffset 2.62m
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RL 130.10mAHDOffset -0.39m
R11-BH105RL 130.60mAHDOffset -14.91m
R11-BH110
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RL 172.78mAHDOffset 46.50m
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RL 179.59mAHDOffset -13.85m
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RL 183.50mAHDOffset -19.15m
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RL 157.61mAHDOffset -55.84m
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RL 143.13mAHDOffset 8.90m
NWR-BH024
RL 132.52mAHDOffset -6.63m
NWR-BH028
NWR-TP005^
RL 167.62mAHDOffset 31.25m
NWR-BH091
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?
MARKER BED
MARKER BED
MARKER BED
MARKER BED
DEB REKRAM
MARKER BED
DEB REKRAM
MARKER BED
MARKER BED
MARKER BED
MARKER BED
HAWKESBURYSANDSTONE
ASHFIELDSHALE
KELLYVILLE LAMINITE
SILTSTONE INTERBEDS
FILL / RESIDUAL SOIL / EW SHALE
FINER GRAINED
SANDSTONE MEDIUM GRAINED
ROUSE HILL
KELLYVILLE LAMINITE
REGENTVILLE SILTSTONE
MULGOA LAMINITE
KELLYVILLE LAMINITE
ROUSE HILLSANDSTONE
MEDIUM & COARSERGRAINED
INTERBEDDEDSANDSTONE & SILTSTONE
CASTLE HILLCROSS OVER CAVERN
ASHFIELDSHALE
TRACK LEVEL
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project:
title:
NORTH WEST RAIL LINKGEOTECHNICAL SERVICES
DRAFT DIAGRAMMATIC GEOTECHNICAL LONG SECTION
figure no:
LONGITUDINAL SECTION
HEIGHT DATUM: A.H.D.
SHEET 4 OF 9
CUDGEGONG
SYDNEY
FIGURE B5
drawn
approved
date
scale
originalsize A4
MG / MH
CJP
29 / 02 / 12
NTS
service provider:clientNOTES:
1. SECTION PREPARED FOR DIAGRAMMATIC PURPOSES ONLY (NOT FOR INTERPRETATION)
2. ONLY ABOUT 50% OF BOREHOLE LOGS REPRESENTED ON LONG SECTION
3. ALIGNMENT BASED ON SUPPLIED DRAFT CONCEPT DESIGN DATED 23RD DECEMBER 2011
4. SECTION VERTICALLY EXAGGERATED 20 TIMES (NOT TO SCALE)
5. TUNNEL CROWN AND INVERT LEVELS SHOWN ARE APPROXIMATE ONLY
PROPOSED TRACKLEVEL (mAHD)
EXISTING SURFACELEVEL (mAHD)
CHAINAGE (m)
DATUM : RL
Page 175 figure 49.pdf 1 24/08/2015 1:43 pm
Page 175 figure 49.pdf 1 24/08/2015 1:47 pm
Figure 66: A page from Sydney Metro Northwest Environmental Impact Statement 1, Appendix A – Geological long section.
Figure 67: An example of mapping the route as displayed in Sydney Metro Northwest Environmental Impact Statement 1, Appendix A – Geological long section.
202 203TOPIC THREE: PLANNING, DESIGNING AND BUILDING A RAILWAY FASTTRACKING THE FUTURE | SECONDARY EDITION NOVEMBER 2016
Topic Three:
Planning
, desig
ning
and b
uilding
a railway
Step 2 – Listing the rock typesWith reference to Figure 66 (page 201) (the geological long section detailing the rock and soil types for each section of the alignment), students list the rock types that will need to be excavated to construct these different sections of the line. They are instructed to mark these rock types on Activity sheet 1 (page 205).
Using the Castle Hill Station example shown in Figure 66, the teacher guides the students to identify the soil and rock types that must be excavated. In order of descending depth these are:
1. Fill residual soil/EW shale (shown in pink/salmon on the cross-section).
2. Kellyville laminate (a type of Ashfield shale, shown in green).
3. Rouse Hill sandstone (a type of Ashfield shale, shown in green).
4. Interbedded sandstone and siltstone (shown in grey).
5. Hawkesbury sandstone (shown in yellow).
Other examples such as Cudgegong Road Station are almost completely Hawkesbury sandstone (shown in yellow) and Bella Vista Station is almost entirely resting on Ashfield shale (shown in green).
Students should explore the Index and Geotechnical Legend (Figure 68) lists all of the rock and soil types on the internet.
Soil and rocks
Topsoil
Fill
Asphalt
Silty gravel
Clay
Silty clay
Clayey sand
Cobbles
Clayey silt
Sand
Silty sand
Gravelly clay
Gravelly sandy clay
Sandy clayey silt
Sandy silt
Sandy silty clay
Silt
Clayey gravel
Gravelly sandy silt
Gravelly sand
Silty clayey gravel
Silty sandstone
Conglomerate
Shale
Mudstone
Sandstone
Siltstone
Sandstone
Claystone
Interlaminated siltstone and sandstone
Interbedded siltstone and sandstone
Interbedded shale and sandstone
Interbedded shale and siltstone
Geological material
Fill
Fill/residual soil/EW shale
Alluvium
Ashfield shale
Mittagong formation
Hawkesbury sandstone
Bringelly shale
Siltstone or siltstone and sandstone interbedded unit
Minchinbury sandstone
Volcanic ash correlation layer
Possible fault displacement
#
STA
TU
TOR
Y
P
LAN
NIN
G
A
ND
AS
SE
SS
ME
NT
FR
AM
EW
OR
K
12 Strateg
ic C
ontext
VERY SOFTSOFTFIRMSTIFFVERY STIFFHARDFRIABLEVERY LOOSELOOSEMEDIUM DENSEDENSEVERY DENSE
VSSFSTVSTHFbVLLMDDVD
ROCK STRENGTH
EXTREMELY LOWVERY LOWLOWMEDIUMHIGHVERY HIGHEXTREMELY HIGH
ELVLLMHVHEH
WEATHERING GRADE
EXTREMELY WEATHEREDHIGHLY WEATHEREDMODERATELY WEATHEREDSLIGHTLY WEATHEREDFRESH
EWHWMWSWFR
INDEX AND GEOTECHNICAL LEGEND
SOIL & ROCK KEY (CONTINUE) SOIL CONSISTENCY/RELATIVE DENSITY TYPICAL BOREHOLE / TESTPIT DETAILS
EXPLORATORY HOLE NUMBERLATERAL OFFSET FROM LONGSECTIONREDUCED LEVEL (m AHD)SOIL CONSISTENCYRELATIVE DENSITY
STANDARD PENETRATIONTEST RESULT
WEATHERING GRADE
FINAL DEPTH
SHALE CLASTS
IN SITU PERMEABILITY(PACKER TEST RESULTS)
NO CORE
SOIL & ROCK KEY
INDEX
N =23
SHEAR ZONE / FAULTED ZONE
GROUND WATER LEVEL
IRONSTAINED CORE
GEOLOGICAL MATERIAL
FILL
FILL / RESIDUAL SOIL / EW SHALE
ALLUVIUM
ASHFIELD SHALE
MITTAGONG FORMATION
HAWKESBURY SANDSTONE
BRINGELLY SHALE
SILTSTONE OR SILTSTONE &SANDSTONE INTERBEDDED UNIT
MINCHINBURY SANDSTONE
CLAY
SILTY CLAY
SILTSTONE
INTERBEDDED SILTSTONE & SANDSTONE
SANDY CLAY
ASPHALT
CLAYEY SAND
SILTY SANDSTONE
CLAYEY SILT
SHALE
SAND
FILL
CONCRETE
CONGLOMERATE
COBBLES
SILTY GRAVEL
MUDSTONE
GRAVELLY CLAY
TOPSOIL
INTERBEDDED SHALE & SANDSTONE
INTERBEDDED SHALE & SILTSTONE
GRAVELLY SANDY CLAY
SANDY CLAYEY SILT
SANDY SILT
CLAYSTONE
SANDY SILTY CLAY
SILT
CLAYEY GRAVEL
GRAVELLY SANDY SILT
GRAVELLY SAND
SILTY CLAYEY GRAVEL
SILTY SAND
SANDSTONE
INTERLAMINATED SILTSTONE & SANDSTONE
INTERLAMINATED CLAYSTONE & SILTSTONE
DISCLAIMER:
COFFEY AND AECOM MAKE NO REPRESENTATIONS OR WARRANTIESABOUT THE ACCURACY, RELIABILITY, COMPLETENESS OR SUITABILITYFOR ANY PARTICULAR PURPOSE OF THE DATA. BY USING THE DATA YOUAGREE THAT COFFEY AND AECOM ARE UNDER NO LIABILITY FOR ANYLOSS OR DAMAGE (INCLUDING CONSEQUENTIAL DAMAGE) THAT YOUMAY SUFFER FROM USE OF DATA.
MARKER BED WITHINROUSE HILL SILTSTONE
project:
title:
NORTH WEST RAIL LINKGEOTECHNICAL SERVICES
DRAFT DIAGRAMMATIC GEOTECHNICAL LONG SECTION
figure no:
LONGITUDINAL SECTION
HEIGHT DATUM: A.H.D.
INDEX AND GEOTECHNICAL LEGEND
FIGURE B1
drawn
approved
date
scale
originalsize A4
MG / MH
CJP
29 / 02 / 12
NTS
service provider:clientNOTES:
1. SECTION PREPARED FOR DIAGRAMMATIC PURPOSES ONLY (NOT FOR INTERPRETATION)
2. ONLY ABOUT 50% OF BOREHOLE LOGS REPRESENTED ON LONG SECTION
3. ALIGNMENT BASED ON SUPPLIED DRAFT CONCEPT DESIGN DATED 23RD DECEMBER 2011
4. SECTION VERTICALLY EXAGGERATED 20 TIMES (NOT TO SCALE)
5. TUNNEL CROWN AND INVERT LEVELS SHOWN ARE APPROXIMATE ONLY
HW
FR
HWFR
HW
SW
HW
SW
FR
HW
MW
FR
FR
SW
FR
MW
FR
1.1uL
0.4uL
MASSIVE
RL100.00mAHDOffset 1.00m
NWR-BH000
50
VOLCANIC ASH CORRELATION LAYER
POSSIBLE FAULT DISPLACEMENT
FIGURE NO. TITLE
B1 INDEX ANDGEOTECHNICALLEGEND
B2 SHEET 1 OF 9
B3 SHEET 2 OF 9
B4 SHEET 3 OF 9
B5 SHEET 4 OF 9
B6 SHEET 5 OF 9
B7 SHEET 6 OF 9
B8 SHEET 7 OF 9
B9 SHEET 8 OF 9
B10 SHEET 9 OF 9
Page 177 rock sample EIS 1.pdf 1 24/08/2015 1:48 pm
Figure 68: The Index and Geotechnical Legend lists of all the soil and rock types the railway travels across.
Step 3 – Making a map � Using the maps and diagrams in Sydney Metro Northwest Environmental Impact Statement 1, (Appendix A, page 201 – Geological long section) as a guide, students draw the route of Sydney Metro Northwest on their map (Activity sheet 1, page 205), marking those sections that run above ground and underground
� Using the Geological long section diagrams, students note down the heights above sea level of each main part of the track. The scale used on the Geological long sections is marked in mAHD, the abbreviation for elevation in metres with respect to the Australian Height Datum, that sets mean sea level as zero elevation
� Close reading of the geological long section diagrams can also provide an opportunity for the teacher to discuss surveying and the measurement called ‘chainage’ along the foot of each diagram
� It is also important to note while examining these geological diagrams, that the cross-sections are vertically exaggerated 20 times and not to scale
� Students should summarise their geological findings and describe the geology of the area in general terms.
205FASTTRACKING THE FUTURE | SECONDARY EDITION NOVEMBER 2016204 TOPIC THREE: PLANNING, DESIGNING AND BUILDING A RAILWAY
Teacher references and extension workSome students will become very interested in the geology and engineering of tunnels.
� Explore Sydney rock types in greater detail. Showing students rock microstructure (the ways the minerals or particles are joined in rocks) can introduce them to this field. Using photomicrographs of rocks, for example, it is possible to examine the composition and resultant strength of the rock
� Explore tunnelling methodologies. They may look either at earlier tunnelling systems and compare them or explore contemporary tunnelling technology on the web.
Figure 69: Tunnelling through rock using a road header machine.
Figure 70: Tunnel boring machine information sheet.
sydneymetro.info/northwest1800 019 989
DELIVERING AUSTRALIA’S LONGEST RAILWAY TUNNELS
October 2015: Size and scale of a TBM in action at Castle Hill.
HOW BIG IS IT?
Length: up to 120m
A380
A380
Meal room/toilets Operator
=weight>900 tonnes
Holden Commodores570
people work on each TBM at any one time
15
hardened steel cutters on each cutting head
40internal tunnel diameter
6m
around-the-clock operation underground
24/7
of tunnel cut every week, on average
173m
boring through Sydney sandstone, the rest shale
60%
Olympic swimming pools or 2.8 million tonnes of crushed rock generated by tunnelling
1,00058m
Averagetunneldepth
29m
Surfacelevel
Maximumtunneldepth
Cutterhead GripperRing build areaSpoil conveyor
Groutingpumps
Concretesegments Shields
Grippers extend out to the rock surface. Rock is crushed by high strength alloy steel discs on the cutterhead.
Crushed rock is scooped into the machine’s head and on to a conveyor belt.
The conveyor moves the rock through the machine and out of the tunnel behind it.
The machine moves forward about 1.7m and then the process starts again.
Concrete ring segments are delivered to the ring building area. Concrete ring is built by
putting together the segments using a special vacuum lifting device.
When complete, the ring is connected to the previous ring.
The gap between the concrete ring and the rock is filled with grout – this helps keep water out of the tunnel.
HOW A TUNNEL BORING MACHINE (TBM) WORKS
3
1
4
2
5
6
7
8
Castle HillCastle HillNorwestNorwest
EppingEpping
ShowgroundShowgroundTBM operationssupportTBM operationssupport
Bella VistaBella VistaTBMs 1 and 29km to CherrybrookTBMs 1 and 29km to Cherrybrook
CherrybrookCherrybrookTBMs 3 and 46km to EppingTBMs 3 and 46km to Epping
44 tunnel boring machines (TBMs)
1515kilometres of twin tunnels from Bella Vista to Epping – Australia’s longest rail tunnels
16011_Community Open Boards_AO.indd 2 28/01/2016 5:50 pm
ACTIVITY SHEET 1
An example base map, showing Epping to Rouse Hill.
This can be created easily by typing ‘Castle Hill, NSW’ into Google Maps, and capturing the screen, and printing it.
http://maps.google.com.au/maps?q=Castle+Hill,+NSW&z=13
Figure 71: An example base map, showing Epping to Rouse Hill. Copyright, Google Maps 2013.