LANDSCAPES, ROCKS AND TUNNELS: PRACTICAL CONSIDERATIONS IN

TRANSPORT GEOGRAPHY FAST FACTS

Key Learning Unit or lesson title and main focus questions Most appropriate level and ON THE WEB Area suggested number of lessons Web links

Geography Landscapes, rocks and tunnels: Practical considerations in Stage 5 SubmissionsDOWNLOAD Report Stage 1, Chapter 2 transport geography http://www.sydneymetro.info/documents

What landscapes and rock types does the railway cross, both INFO underground and over ground? i Metro Northwest Environmental Impact Statement 2, Appendix C – Geological 1–3 lessons 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

Teacher briefing Sydney Metro Northwest Environmental Impact Statement 1, Appendix A – Geological Sydney Metro Northwest Environmental Impact Statement 2, provides easily accessed long section geological data on the construction of the Sydney Metro Northwest tunnels. This activity http://www.sydneymetro.info/sites/default/files/26_Appendix_A_-_DGRs__CoA___SoC. provides Stage 5 students with the opportunity to explore the basic ideas of geotechnics and pdf%3Fext%3D.pdf some of the geological issues that need to be solved when building a tunnel. Focus questions: Sydney Metro Northwest Environmental Impact Statement 2, Project Description – „„ Which part of Sydney Metro Northwest is underground? Operations Part 1, Chapter 6 http://www.sydneymetro.info/sites/default/files/07_Ch_6_Project_Description_-_ „„ What rock types does it pass through? Operation_-_Part_1_of_2.pdf%3Fext%3D.pdf „„ What technical problems might these rock types present to engineers and how will they solve these? Sydney geological map „„ Do the above ground sections of the rail line present the same or different challenges? http://www.resources.nsw.gov.au/__data/assets/image/0005/287204/Sydney_500k.jpg and building a railway

Requirements for these lessons Any topographic map of the area, or SIX Viewer Planning, designing https://six.nsw.gov.au/wps/portal „„ Internet connected computers Topic Three:

„„ Google Earth or Google Maps „„ Activity sheet 1 – Map of Epping-Rouse Hill Background information „„ Graph paper. Students explore geological problems engineers have solved when planning Sydney Metro

Northwest. The main rock type in this area is Hawkesbury that can be easily

Key terms and vocabulary tunnelled, but may require support. Tunnels are unlike any other civil engineering structures. Geotechnics, cross-section, geological long section. 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.

198 TOPIC THREE: PLANNING, DESIGNING AND BUILDING A RAILWAY FASTTRACKING THE FUTURE | SECONDARY EDITION NOVEMBER 2016 199 Page 175 figure 49.pdf 1 24/08/2015 1:47 pm Page 175 figure 49.pdf 1 24/08/2015

A passage describing the planned tunnels from the Sydney Metro Northwest

Environmental Impact Statement 2 Overview CHERRYBROOK STATION 200 CUDGEGONG (CUT & COVER OR OPEN STATION) Page 175 figure 49.pdf 1 24/0 SYDNEY The tunnels would have a maximum vertical grade of 4.1% and have been designed 195 CASTLE HILL RD 190 A CASTLE HILL RD

NWR-BH022 p Offset -19.15m p

OLD NORTHERN RD OLD NORTHERN RL 183.50mAHD

R01-BH03 e Offset 36.43m with an appropriate curvature to accommodate an operating speed of 100 km per 185 n NWR-BH021 RL 179.00mAHD CASTLE HILL RD Offset -13.85m FILL / RESIDUAL SOIL / EW d

RL 179.59mAHD i x

R03-BH241 _ HIGHS RD

180 Offset -11.85m A RL 173.95mAHD

NWR-BH020 CASTLE HILL RD hour. The vertical gradient of the tunnels is influenced by the topography, geological Offset 14.31m RL 174.59mAHD NWR-BH019 Offset 46.50m RL 172.78mAHD 175

CASTLE HILL STATION NWR-BH091 8

MULGOA LAMINITE /2015 1:43 pm Offset 31.25m constraints, presence of watercourses and the alignment has been designed to provide RL 167.62mAHD 170 (CUT & COVER) ASHFIELD CASTLE HILL SHALE CROSS OVER CAVERN sufficient clearance to existing and proposed building basement levels (for example below 165 NWR-BH023 ? Offset -55.84m REGENTVILLE SILTSTONE NWR-TP005^ Castle Hill town centre). The tunnel crown (top of the tunnel) would be located at its 160 RL 157.61mAHD 155

KELLYVILLE LAMINITE MC MULLEN AVE shallowest point approximately three metres below ground surface and at its deepest 150

MARKER BED CASTLE ST NWR-BH024 MARK Offset 8.90m ER BE MARKER BED KELLYVILLE LAMINITE R01-BH04 RL 143.13mAHD D Offset 14.06m R03-BH242 RL 142.00mAHD ROUSE HILL 145 Offset 2.62m R11-BH102 RL 140.74mAHD Offset -21.84m point approximately 58 m below ground surface. On average the tunnels would be more RL 135.40mAHD

WINCHCOMBE PL MARKER BED MARKER B 140 ED NWR-BH028 R02-BH103 SILTSTONE INTERBEDS Offset -6.63m ASHFIELD Offset -14.03m RL 135.09mAHD RL 132.52mAHD SHALE 40.96 typically in the 20–25 m depth range and tunnel depth would tend to be at its shallowest SANDSTONE MEDIUM GRAINED 135 R11-BH110 Offset -14.91m R11-BH105 RL 130.60mAHD Offset -0.39m TRACK LEVEL RL 130.10mAHD 40.15

130 42 at station locations and at the northern tunnel portal. KELLYVILLE LAMINITE D BE RKER 40 MA 125

MARKER BED

ROUSE HILL MARKER BED MARKER BED MARKER BED SANDSTONE 120 MARKER BED

60.35 HAWKESBURY INTERBEDDED SANDSTONE 115 SANDSTONE & SILTSTONE FINER GRAINED 16 60 70.05 Syllabus links 110

50 MEDIUM & COARSER DATUM : RL 105 GRAINED PROPOSED TRACK LEVEL (mAHD) 101.64 104.42 107.20 109.99 112.77 114.69 115.00 115.00 115.00 115.00 114.95 114.00 113.00 113.25 115.80 118.80 121.80 124.80 127.80 130.80 133.80 136.80 139.80 142.80 145.80 148.80 151.80 154.80 157.80 160.65 161.96 162.00 162.00 161.48 159.42

EXISTING SURFACE LEVEL (mAHD) 126.91 129.71 138.36 139.92 141.16 141.49 142.06 145.79 152.42 146.66 137.08 151.17 179.33 185.62 189.89 188.41 186.62 186.65 185.85 173.03 168.17 171.51 174.31 174.46 170.36 172.86 181.89 181.68 Geography K-10 130.54 132.60 137.44 180.00 175.94 175.00 168.64

CHAINAGE (m) 34300 34200 34100 34000 33900 33800 33700 33600 33500 33400 33300 33200 33100 33000 32900 32800 32700 32600 32500 32400 32300 32200 32100 32000 31900 31800 31700 31600 31500 31400 31300 31200 31100 31000 30900

client service provider: project: Figure 66: A page from Sydney Metro Northwest Environmental Impact Statement 1, 2 NOTES: LONGITUDINAL SECTION drawn MG / MH - Geography Stage 5 - Changing places NORTH WEST RAIL LINK 7 HEIGHT DATUM: A.H.D. approved CJP GEOTECHNICAL SERVICES Appendix1. SECTION PREPARED FOR DIAGRAMMATICA – PURPOSESGeological ONLY (NOT FOR INTERPRETATION) long section. DRAFT DIAGRAMMATIC GEOTECHNICAL LONG SECTION 2. ONLY ABOUT 50% OF BOREHOLE LOGS REPRESENTED ON LONG SECTION date 29 / 02 / 12 3. ALIGNMENT BASED ON SUPPLIED DRAFT CONCEPT DESIGN DATED 23RD DECEMBER 2011 title: 4. SECTION VERTICALLY EXAGGERATED 20 TIMES (NOT TO SCALE) scale NTS SHEET 4 OF 9 - the management and planning of Australia’s urban future. 5. TUNNEL CROWN AND INVERT LEVELS SHOWN ARE APPROXIMATE ONLY original figure no: size A4 FIGURE B5 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 and building a railway Planning, designing (GE5-7) acquires and processes geographical information by selecting and using appropriate and relevant geographical tools for inquiry Topic Three: (GE5-8) communicates geographical information to a range of audiences using a variety of strategies.

Learning experiences

Step 1 – Class discussion Display 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. Figure 67: An example of mapping the route as displayed in Sydney Metro Northwest Environmental Impact Statement 1, Appendix A – Geological long section.

200 TOPIC THREE: PLANNING, DESIGNING AND BUILDING A RAILWAY FASTTRACKING THE FUTURE | SECONDARY EDITION NOVEMBER 2016 201

INDEX AND GEOTECHNICAL LEGEND Step 2 – Listing the rock types 24/08/2015 1:48 pm Page 177 rock sample EIS 1.pdf 1

INDEX SOIL & ROCK KEY (CONTINUE) SOIL CONSISTENCY/RELATIVE DENSITY TYPICAL BOREHOLE / TESTPIT DETAILS With reference to Figure 66 (page 201) (the geological long section detailing the rock and VS VERY SOFT COBBLES S SOFT F A A P S 1 F FIRM NWR-BH000 EXPLORATORY HOLE NUMBER

FIGURE NO. TITLE 2 ST STIFF LATERAL OFFSET FROM LONG soil types for each section of the alignment), students list the rock types that will need to be CLAYEY SILT Offset 1.00m VST VERY STIFF RL100.00mAHD SECTION B1 INDEX AND H HARD

T REDUCED LEVEL (m AHD) R GEOTECHNICAL SAND Fb FRIABLE L S N SOIL CONSISTENCY excavated to construct these different sections of the line. They are instructed to mark these LEGEND VL VERY LOOSE L LOOSE RELATIVE DENSITY SILTY SAND C S N =23 HW B2 SHEET 1 OF 9 MD MEDIUM DENSE A A t

o D DENSE FR STANDARD PENETRATION A S rock types on Activity sheet 1 (page 205). GRAVELLY CLAY r VD VERY DENSE HW TEST RESULT D B3 SHEET 2 OF 9 n FR a

HW t t GRAVELLY SANDY CLAY T B4 SHEET 3 OF 9 ROCK STRENGTH SW e e g E NN I M

B5 SHEET 4 OF 9 SANDY CLAYEY SILT x GROUND WATER LEVEL Using the Castle Hill Station example shown in Figure 66, the teacher guides the students to EL EXTREMELY LOW HW t U i VL VERY LOW B6 SHEET 5 OF 9 SANDY SILT c L LOW S M MEDIUM SW WEATHERING GRADE identify the soil and rock types that must be excavated. In order of descending depth these are: B7 SHEET 6 OF 9 H HIGH SANDY SILTY CLAY E VH VERY HIGH FR

B8 SHEET 7 OF 9 EH EXTREMELY HIGH T HW S SILT IRONSTAINED CORE MW B9 SHEET 8 OF 9 W WEATHERING GRADE FR SHEAR ZONE / FAULTED ZONE 1. Fill residual soil/EW shale (shown in pink/salmon on the cross-section). CLAYEY GRAVEL O N B10 SHEET 9 OF 9 M GRAVELLY SANDY SILT EW EXTREMELY WEATHERED HW HIGHLY WEATHERED MARKER BED WITHIN MW MODERATELY WEATHERED FR ROUSE HILL SILTSTONE 2. Kellyville laminate (a type of , shown in green). GRAVELLY SAND SW SLIGHTLY WEATHERED R G O FR FRESH

E 1.1uL SILTY CLAYEY GRAVEL SHALE CLASTS

SILTY SANDSTONE SW 3. Rouse Hill sandstone (a type of Ashfield shale, shown in green). Y GEOLOGICALN MATERIAL R CONGLOMERATE FR

SHALE FILL MW

SOIL & ROCK KEY T 4. Interbedded sandstone and siltstone (shown in grey). K MUDSTONE FILL / RESIDUAL SOIL / EW SHALE 0.4uL IN SITU PERMEABILITY (PACKER TEST RESULTS) TOPSOIL SANDSTONE ALLUVIUM 5. Hawkesbury sandstone (shown in yellow). FR FILL SILTSTONE ASHFIELD SHALE MASSIVE Other examples such as Cudgegong Road Station are almost completely Hawkesbury ASPHALT CLAYSTONE CONCRETE INTERLAMINATED SILTSTONE & SANDSTONE SILTSTONE OR SILTSTONE & SANDSTONE INTERBEDDED UNIT 50 FINAL DEPTH sandstone (shown in yellow) and Bella Vista Station is almost entirely resting on Ashfield shale SILTY GRAVEL INTERBEDDED SILTSTONE & SANDSTONE HAWKESBURY SANDSTONE CLAY INTERLAMINATED CLAYSTONE & SILTSTONE (shown in green). # DISCLAIMER: SILTY CLAY INTERBEDDED SHALE & SANDSTONE MINCHINBURY SANDSTONE COFFEY AND AECOM MAKE NO REPRESENTATIONS OR WARRANTIES ABOUT THE ACCURACY, RELIABILITY, COMPLETENESS OR SUITABILITY SANDY CLAY INTERBEDDED SHALE & SILTSTONE VOLCANIC ASH CORRELATION LAYER FOR ANY PARTICULAR PURPOSE OF THE DATA. BY USING THE DATA YOU AGREE THAT COFFEY AND AECOM ARE UNDER NO LIABILITY FOR ANY LOSS OR DAMAGE (INCLUDING CONSEQUENTIAL DAMAGE) THAT YOU Students should explore the Index and Geotechnical Legend (Figure 68) lists all of the rock and CLAYEY SAND NO CORE POSSIBLE FAULT DISPLACEMENT MAY SUFFER FROM USE OF DATA.

client service provider: project: soil types on the internet. NOTES: LONGITUDINAL SECTION drawn MG / MH NORTH WEST RAIL LINK HEIGHT DATUM: A.H.D. approved CJP GEOTECHNICAL SERVICES 1. SECTION PREPARED FOR DIAGRAMMATIC PURPOSES ONLY (NOT FOR INTERPRETATION) DRAFT DIAGRAMMATIC GEOTECHNICAL LONG SECTION 2. ONLY ABOUT 50% OF BOREHOLE LOGS REPRESENTED ON LONG SECTION date 29 / 02 / 12 3. ALIGNMENT BASED ON SUPPLIED DRAFT CONCEPT DESIGN DATED 23RD DECEMBER 2011 title: Soil and rocks 4. SECTION VERTICALLY EXAGGERATED 20 TIMES (NOT TO SCALE) scale NTS INDEX AND GEOTECHNICAL LEGEND 5. TUNNEL CROWN AND INVERT LEVELS SHOWN ARE APPROXIMATE ONLY original figure no: size A4 FIGURE B1

Figure 68: The Index and Geotechnical Legend lists of all the soil and rock types the railway travels across. Topsoil Gravelly clay Silty sandstone Interlaminated siltstone and sandstone Fill Gravelly sandy clay Conglomerate Step 3 – Making a map Interbedded siltstone Asphalt Sandy clayey silt Shale

and sandstone „„ Using the maps and diagrams in Sydney Metro Northwest Environmental Impact Statement 1, and building a railway Silty gravel Sandy silt Mudstone Planning, designing Interbedded shale (Appendix A, page 201 – Geological long section) as a guide, students draw the route of Clay Sandy silty clay Sandstone and sandstone Sydney Metro Northwest on their map (Activity sheet 1, page 205), marking those sections Topic Three: Silty clay Silt Siltstone Interbedded shale that run above ground and underground and siltstone Clayey sand Clayey gravel Sandstone „„ Using the Geological long section diagrams, students note down the heights above sea level of Cobbles Gravelly sandy silt Claystone 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 Clayey silt Gravelly sand

mean sea level as zero elevation Sand Silty clayey gravel „„ Silty sand 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 Geological material „„ It is also important to note while examining these geological diagrams, that the cross-sections are vertically exaggerated 20 times and not to scale

Fill Bringelly shale „„ Students should summarise their geological findings and describe the geology of the area Fill/residual soil/EW shale Siltstone or siltstone and sandstone interbedded unit in general terms. Alluvium Minchinbury sandstone Ashfield shale Volcanic ash correlation layer Mittagong formation Possible fault displacement Hawkesbury sandstone

202 TOPIC THREE: PLANNING, DESIGNING AND BUILDING A RAILWAY FASTTRACKING THE FUTURE | SECONDARY EDITION NOVEMBER 2016 203 ACTIVITY SHEET 1

Teacher references and extension work 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, Some students will become very interested in the geology and engineering of tunnels. and printing it. „„ Explore Sydney rock types in greater detail. Showing students rock microstructure http://maps.google.com.au/maps?q=Castle+Hill,+NSW&z=13 (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.

DELIVERING AUSTRALIA’S LONGEST RAILWAY TUNNELS

Surface tunnel boring machines (TBMs) HOW A TUNNEL BORING MACHINE (TBM) WORKS Grippers extend out Figure 71: An example base map, showing Epping to Rouse Hill. Copyright, Google Maps 2013. level 4 1 to the rock surface. kilometres of twin tunnels from Bella Vista Rock is crushed by high strength alloy steel discs to Epping – Australia’s longest rail tunnels When complete, the ring is 15 on the cutterhead. connected to the previous ring.

The gap between the concrete Crushed rock is scooped into ring and the rock is filled with 2 the machine’s head and grout – this helps keep water on to a conveyor belt. out of the tunnel. 6 3 The conveyor moves the rock through the 7 machine and out of 29m the tunnel behind it. Average tunnel 5 Bella Vista depth 8 TBMs 1 and 2 9km to Cherrybrook 4 October 2015: Size and scale of a TBM in action at Castle Hill. Norwest Castle Hill HOW BIG IS IT? Concrete ring The machine moves segments are forward about 1.7m

A380 A380 delivered to the and then the process ring building area. Concrete ring is built by starts again. Showground >900 tonnes TBM operations putting together the support Cherrybrook weight Epping segments using a special TBMs 3 and 4 Length: up to 120m = 570 vacuum lifting device. 6km to Epping Holden Commodores

Spoil conveyor Ring build area Gripper Cutterhead

60% boring through , the rest shale

173m 6m 40 of tunnel cut internal tunnel hardened steel every week, diameter cutters on each Grouting Concrete on average cutting head pumps segments Shields Meal room/toilets Operator 58m Maximum 1,000 15 24/7 Olympic swimming pools or people work around-the-clock tunnel 2.8 million tonnes of crushed on each TBM operation depth rock generated by tunnelling at any one time underground

sydneymetro.info/northwest 1800 019 989

16011_Community Open Boards_AO.indd 2 28/01/2016 5:50 pm Figure 70: Tunnel boring machine information sheet.

204 TOPIC THREE: PLANNING, DESIGNING AND BUILDING A RAILWAY FASTTRACKING THE FUTURE | SECONDARY EDITION NOVEMBER 2016 205