C2 utilities relocation method

In association with:

ENABLING WORKS CONTRACT 2 Appendix M : Utilities Relocation Method Separable Portion 1 – Cut and Cover Works

COMMERCIAL IN CONFIDENCE

Appendix M Utilities Relocation Method

Auckland City Rail Link

1 WYNDHAM ST PERMANENT WORKS These works are required to provide the permanent connection between the existing stormwater system outside the pile wall and the new system to be installed inside the pile wall in the future. The majority of these works need to be completed prior to tunnel box excavation to minimise the delay to the excavation which is on the critical path. The works will be scheduled so that all the set-up works can be completed prior to tunnel box excavation and then the only works required during tunnel box excavation is breaking through the pile wall and installing the pipe. It is anticipated that these works will take 25 days and can be completed prior to piling. These works will require separate traffic management.

1.1

CONSTRUCTION SEQUENCE 1. Close traffic to Wyndham Street and western side of Albert St at Wyndham St intersection.

2. Carry out service relocations northwest of existing SWMH 9/1 to ensure adequate space available for new SWMH 9/1. Drawings indicate that relocations should not be required.

3. Excavate and install new SWMH 9/1 northwest of existing SWMH 9/1. Note that this manhole will need to be 1m deeper than that shown in the design to allow placement of muck skip below pipe invert during pilot bore operations. a. New SWMH 9/1 northwest of existing SWMH 9/1 i. Diameter: 2.5m ii. IL: 15.38m (allowing for an additional 1m for pilot bore equipment) iii. Depth To Invert: 6.27m 4. Install new pipe from new SWMH 9/1 to existing SWMH 9/1 using pilot bore method. a. Pipe i. Length: 5.75m ii. Grade: 6.6% iii. Material: GRP iv. Size: 375mm 5. Plug end of newly installed pipe between new SWMH 9/1 and existing SWMH 9/1.

6. Coinciding with excavation inside the tunnel box, install new pipe from new SWMH 9/1 past pile wall alignment. a. Pipe i. Length: approx. 12m ii. Grade: 0.5% iii. Material: GRP iv. Size: 375mm 7. Follow-up works. When temporary stormwater system inside pile wall is live, then the bung in the pipe between the new SWMH 9/1 and existing SWMH 9/1 can be removed and flows allowed to travel down new line.

Stormwater Works outside Trench Alignment

Vector,Watermain and Chorus Works outside Trench Alignment

Figure 1: Wyndham Street Permanent Early Works

2 WYNDHAM STREET TEMPORARY DIVERSION WORKS These works are required in order to avoid a clash between the existing stormwater system and the western pile wall. It is anticipated that these works will be completed at the same time as the Kingston – Wyndham St Permanent Stormwater works. This work is temporary work that will become redundant once the new stormwater system is installed. These works are expected to have a duration of 10 days. These works will require separate traffic management works.

2.1

CONSTRUCTION SEQUENCE 1. Slew electrical cables from SWMH 9/3 to SWMH 9/2 to the west to make room for temporary diversion line from SWMH 9/3.

2. Access existing SWMH 9/3 and install pump. Pump storm water from existing SWMH 9/3 to SWMH 9/1 via a temporary diversion pipe. This is to prevent flow from SWMH 9/3 affecting connection of temporary line. A temporary plug will need to be installed in EXSWMH 9/1 in the line towards EXSWMH 9/2 to prevent any backflow up line being worked on.

3. Excavate trench from SWMH 9/3 to intersect with existing SW line from SWMH 9/1 to SWMH 9/2 at a point approx. 2m north of SWMH 9/2. Use a combination of straight and a bend to eliminate having to relocate the existing electrical and fiber optic services.

4. Install Pipe and connect to existing pipe between SWMH 9/1 and SWMH 9/2 at the northern end and SWMH 9/3 at the southern end. This pipe is temporary only. a. Pipe i. Length: approx. 26m ii. Grade: approx. 3.0% iii. Type: Stormboss SN8 iv. Size: 225mm 5. Remove bung from EXSWMH 9/1 and pump/temporary diversion from EXSWMH 9/3 and allow water to run down newly installed temporary line.

6. Demolish existing SWMH 9/2 7. Demolish existing pipes between SWMH 9/2 and SWMH 9/3 and SWMH 9/2 and new connection towards SWMH 9/1.

8. Water to remain flowing through existing system via existing SWMH 9/1 until temporary storm water pipe installed inside pile wall.

9. Re-open Wyndham Street and west side of Albert Street.

Figure 2: Wyndham Street Temporary Diversion Early Works

3 KINGSTON - WYNDHAM STREET (EXCL CONNECTIONS TO EXISTING) EARLY WORKS These works consist of two sections – the permanent works between Kingston and Wyndham St and the temporary diversion works of the existing stormwater at Wyndham St.

3.1

PERMANENT WORKS – KINGSTON TO WYNDHAM ST

These works consist primarily of the partial installation of the new permanent stormwater system between Kingston St and then end of the tunnel box. These works are required to be completed as early works in order to provide a connection between the existing stormwater network and the future temporary stormwater network to allow the demolition of the main sewer trunk line running down Albert Street. Delaying the demolition of the Albert St main will delay excavation which is on the critical path. These works are expected to have a duration of 20 days. These works will require separate traffic management.

3.2

CONSTRUCTION SEQUENCE: - Note: Sequence can be reversed if necessary.

1. Close traffic to Kingston Street and western lane 1.5m lanes on Albert St between Kingston and Wyndham St. 2. Access existing SWMH 3/8 at the Kingston / Albert St intersection. Install bung in outlet of existing SWMH 3/8. Install pump in existing SWMH 3/8 and run temporary pipe along surface to existing SWMH 9/2. This will provide temporary diversion of water while installing new connection to SWMH 3/8 on the existing stormwater line.

3. Excavate and connect to existing network just downstream from existing SWMH 3/8.

Connection will need to be a wye connection with valves. The existing network will need to remain live until the temporary network within pile walls is complete. The new connection will be temporarily closed until temporary network is complete. Once temporary network is complete, one outlet of the wye connection can be closed so that water flows down new line.

4. Remove temporary diversion and allow water to flow down existing stormwater line again.

5. Excavate and install new pipe from existing network at existing SWMH 3/8 to new SWMH 3/7. a. Pipe i. Length: 7.77m ii. Grade: 0.6% iii. Type: Reinforced Concrete RRJ iv. Size: 375mm 6. Excavate and install new SWMH 3/7 and backfill. a. SWMH 3/7 i. Diameter: 1.05m ii. IL: 19.72m iii. Depth To Invert: 2.49m 7. Excavate and install permanent pipe from SWMH 3/7 to future location of SWMH 3/6 and backfill. a. Pipe i. Length: 63.47m ii. Grade: 1.1% iii. Type: Stormboss SN16 iv. Size: 375mm

Figure 3: Kingston to Wyndham Street Early Works

4 CUSTOM STREET INTERSECTION EARLY WORKS The works covered in this section involve the installation of a section of the new permanent stormwater system at the Custom St intersection. These works are required to be completed early to provide a connection to the existing stormwater network for the northern section of the temporary and permanent stormwater networks and also to minimise traffic disturbance. It is anticipated that these works will have a duration of 50 days.

4.1

CONSTRUCTION SEQUENCE: 1. Install traffic management for north east corner of Customs St. 2. Install SWMH 1/1 adjacent to existing Albert St trunk main. a. SWMH 1/1 i. Diameter: 1.5m ii. IL: TBC approx 1.5m iii. Depth To Invert: TBC approx. 4.7m 3. Core a hole through the side of SWMH 1/1 on the face closest to the existing Albert St trunk main. From this window, excavate on a downwards angle until the face of the Albert St trunk main is exposed.

4. Core a hole through the side of the Albert St trunk main from within SWMH 1/1.

5. Install a short pipe stub from SWMH 1/1 into the Albert St trunk main. This pipe may need a flange to help seal to Albert St trunk main. a. Pipe i. Length: est approx. 0.5m ii. Grade: TBC iii. Type: GRP iv. Size: 600mm 6. Seal annulus of pipe with grout.

7. Reopen traffic to north east corner.

8. Await traffic management for south west corner of Customs St. 9. Excavate and install SWMH 1/2. Note that invert level of SWMH will need to be 1m below design invert level to allow for muck skip for pilot bore operations. a. SWMH 1/2 i. Diameter: 2.5m ii. IL: 4.70m iii. DTI: 3.21m 10. Install new permanent pipe from SWMH 1/2 to SWMH 1/1 using pilot bore method. a. Pipe i. Length: 35.03m ii. Grade: 1.7% iii. Type: GRP iv. Size: 600mm 11. Access existing SWMH 2/2 to the west of future SWMH 1/3 location. Install temporary bung in existing outlet. Install pump in existing manhole and run temporary diversion pipe along surface to existing SWMH 2/1 (or nearby catchpit if conflict with traffic). This will provide temporary diversion of water while installing new SWMH 1/3 on the existing stormwater line.

12. Excavate and install SWMH 1/3. Ensure that existing stormwater line from existing SWMH 2/2 is reconnected. However, the existing pipe to the east of new SWMH 1/3 can be abandoned. a. SWMH 1/3 i. Diameter: 1.5m ii. IL: 6.0m iii. Depth To Invert: 2.08m 13. Install new permanent pipe between SWMH 1/2 and SWMH 1/3 from within SWMH 1/2 using the pilot bore method. a. Pipe i. Length: 6.73m ii. Grade: 4.5% iii. Type: GRP iv. Size: 600mm 14. Excavate and partially install permanent pipe between SWMH 1/3 and SWMH 1/4 to a point inside pile wall using open trenching. Install temporary end cap on end of pipe inside pile wall. a. Pipe i. Length: approx. 5.69m ii. Grade: 3.7% iii. Type: Stormboss SN16 iv. Size: 450mm 15. Remove temporary diversion and bung from SWMH 2/2 and allow water to flow down new permanent stormwater line from SWMH 1/3 to SWMH 1/1 then into existing stormwater main.

Figure 4: Customs Street SW Works

5 SWANSON ST WEST WORKS These works are required to provide the permanent connection between the existing stormwater system outside the pile wall and the new temporary and permanent system to be installed inside the pile wall in the future. The reason for conducting these works prior to tunnel box excavation works is to minimise the effect on the excavation for the tunnel box which is on the critical path. It is anticipated that these works will take 12 days and can be completed prior to piling. These works will require separate traffic management.

5.1

CONSTRUCTION SEQUENCE 1. Close traffic to west Swanson Street and western lane of Albert Street at Swanson Street intersection.

2. Slew existing services.

3. Excavate trench from EXSWMH 7/1 to location of future SWMH 3/2 inside pile wall. a. Existing SWMH 7/1 i. Diameter: 1.05m ii. IL: 15.50m iii. Depth To Invert: 2.67m b. Future SWMH 3/2 i. IL: 15.20m ii. DTI: 2.97m 4. Lay pipe from EXSWMH 7/1 to location of future SWMH 3/2 inside pile wall by open excavation. This pipe to remain as part of permanent works. a. Pipe i. Length: approx. 11m ii. Grade: 2.5% iii. Type: Stormboss SN16 iv. Size: 450mm 5. Connect new pipe to EXSWMH 7/1. Install temporary end cap at end of pipe near future SWMH 3/2. Removal of cap and connection to temporary storm water system at a later date once the temp storm water system is complete.

6. Backfill and reinstate.

7. Re-open west Swanson Street and west lane of Albert Street.

Figure 5: Section of Temporary / Permanent SW Line to be Completed Prior to Piling Works

6 SWANSON ST EARLY WORKS There are two sections of stormwater work at Swanson Street. There are works on the eastern side of Albert St adjacent to the Swanson St shaft and works on the western side of Albert St. The works on the eastern side of Albert St are the works that are required to be completed early.

6.1

SWANSON ST EAST EARLY WORKS

These works are required to provide the permanent connection between the newly installed Swanson St shaft and the new temporary and permanent system to be installed inside the pile wall in the future.

The reason for conducting these works as early works is to minimise the effect on the excavation for the tunnel box which is on the critical path and complete prior to piling to maintain the minimum single lane of traffic in each direction. It is anticipated that these works will take 35 days. These works can be completed using the same traffic management arrangement as the Swanson St Shaft.

Figure 6: Swanson St East Works – Plan

Figure 7: Swanson St East Works – Cross-Section

6.2

CONSTRUCTION SEQUENCE -

These works will utilize the same traffic management as the closure to Swanson St for the initial Swanson St shaft works.

1. During excavation of Swanson St shaft cavern, excavate a horizontal tunnel from the Swanson St shaft to a point past the pile wall. Install short stub of pipe to grade for future ANZ Tower connection. Note: when Swanson St shaft concrete base is constructed, concrete will be poured around pipe. a. Pipe: i. Length: approx. 2m ii. Grade: 0.3% iii. Depth To Invert: 10.82m iv. Type: Stormboss SN16 v. Size: 300mm 2. Demolish existing service pit on the southwest corner of the Swanson St shaft.

3. Following installation of Swanson Street shaft but prior to receiving the TBM and piling of the area, excavate and install SWMH 3/1. This can be completed by open trenching. This manhole will have an internal base to allow it to be placed as close to the Swanson St shaft as possible. a. Manhole: i. Diameter: 1.5m ii. IL: 14.93m iii. Depth To Invert: 2.97m

iv. Height: 2.1m riser with internal base 4. From SWMH 3/1, use a concrete coring machine to core an 800mm diameter core through the wall of SWMH 3/1 and into the Swanson St shaft.

5. Install a short pipe stub between Swanson Street shaft and SWMH 3/1 and seal annuluses.

The sealing of the annulus in the Swanson St shaft will require work from a man cage. a. Pipe: i. Length: approx. 0.5m ii. Grade: unknown assume 1.0% iii. Depth To Invert: approx. 3m iv. Type: PE v. Size: 600mm 6. Install a short pipe stub between SWMH 3/1 and pile wall by open trenching. Place temporary cap on pile wall end of pipe stub. Seal annulus within SWMH 3/1 and backfill. a. Pipe: i. Length: approx. 2m ii. Grade: 1.4% iii. Depth To Invert: approx. 3m iv. Type: Reinforced Concrete RRJ v. Size: 600mm 7. Place temporary lid on SWMH 3/1 below underside of future pile cap to avoid clash with pile cap.

8. Backfill SWMH 3/1. Note: there will be no temporary access to SWMH 3/1 until pile cap is demolished.

9. Follow-up works a) Install dropper for pipe between SWMH 3/1 and Swanson St shaft prior to dis-establishing shaft. Do not install earlier as it will restrict access. b) During tunnel box excavation, make connections to previously installed pipe stubs inside pile wall. c) Upon completion of tunnel box backfilling and demolition of pile cap adjacent to SWMH 3/1, the top portion of SWMH 3/1 can be completed. These works will involve the installation of an additional riser and permanent lid on top of the existing SWMH 3/1 base riser.

7 VECTOR, WATER MAIN AND CHORUS WORKS The remaining works to be completed outside of the trench alignment and prior to piling consists of vector gas, vector comms and vector electricity to be installed on the eastern and western footpaths, as well as a water main upgrade on the southern side of the Customs St intersection.

These works are required for a range of reasons which include future proofing for Vectors CBD network, and relocation of the existing network which conflicts with the piles and proposed tree pits.

The Vector relocation and future proof duct installation on both the eastern and western footpaths will terminate at the southern end of the cut and cover trench and will not extend past the bluestone wall.

7.1

VECTOR COMBINED SERVICE TRENCH ON WESTERN FOOTPATH INCLUDING ROAD CROSSINGS AT MILLS LANE, SWANSON ST AND WYNDHAM ST:

The Vector combined service trench is to be installed approximately 1m to the west of the existing kerb line (depending on the results of slot trench investigations). This alignment is driven by the location of the proposed tree pits. The trench will consist of the following dimensions: 

Length - 350m



Width – 1.5m



Depth – 1.2m

The trench will start on the SW corner of Custom St and continue up Albert St approximately 1m inside the existing kerb line. The construction of the combined service trench includes the installation of approximately 2 new communications pits, as well as the excavation of approximately 10 joint pits ranging in size from 5m x 2m x 1.2m to 6m x 2m x 1.4m). The western most traffic lane will be closed within each block during these works to allow trucks and machinery to move in and out of the work area safely. This work includes the installation of vector electricity ducting approximately 50m down Swanson St east to a joint pit which will be excavated over the existing cables. This jointing work is required to energise the Precinct development and provide power supply for their construction works currently programmed for January 2017.

The machinery which will be used for these works includes: 

Saw Cutter



Vacuum Excavation Truck



1.5T, 5.5T Excavator



Jackhammer



Rock Breaker (for Albert St road crossings)



4-6 wheel trucks



Hand Compactor

Vector Communications on Eastern Footpath: Vector communications ducts are required to be installed on the eastern footpath between Customs St and Mills Lane due to a conflict between the existing communications cables and the proposed tree

pits. 1 x 100mm duct will be installed approximately 1m east of the existing kerb line. This communications duct will be installed in a combined trench with the Vector gas main which is summarised below. The installation of the new duct line includes the construction of the 2 new communications pits. A further 120m of vector communications future proof ducting will be installed for 120m between Swanson St and Wyndham St. The trench will consist of the following dimensions: 

Length - 200m



Width – 1.0m



Depth – 1.2m

The machinery which will be used for these works includes: 

Saw Cutter



Vacuum Excavation Truck



1.5T, 5.5T Excavator



Jackhammer



Rock Breaker (for Albert St road crossings)



4-6 wheel trucks



Hand Compacto

7.2

VECTOR GAS ON EASTERN FOOTPATH:

Vector communications ducts are required to be installed on the eastern footpath between Customs St and Swanson St due to a conflict between the existing gas main and the proposed tree pits. 1 x 200mm PE duct will be installed approximately 1m east of the existing kerb line. This gas duct will be installed in the same trench as the Vector communications duct which is required between Customs St and Mills Lane. Between Mills Lant and Swanson St, the gas duct will be installed in its own trench.

The trench will consist of the following dimensions: 

Length - 200m



Width – 1.0m



Depth – 1.2m

The machinery used for the vector gas installation will be as per the machinery listed above for the vector comms trench.

7.3

WATERMAIN UPGRADE CUSTOMS ST SOUTH:

The existing water main crossing Albert St on the southern side of the Customs St intersection has been deemed by Watercare as being too brittle to be supported across the trench for the duration of cut and cover trench construction. The watermain is therefore to be upgraded to PE pipe in its existing location. This work will be carried out prior to trench excavation and the PE pipe will then be supported during construction of the running tunnels.

The trench will consist of the following dimensions: 

Length – 25m



Width – 1.0m



Depth – 1.5m

The machinery used for construction of the watermain upgrade will include:



Saw Cutter



Vacuum Excavation Truck



Excavator



Jackhammer



Rock Breaker (If concrete is located in the roadway)



4-6 wheel trucks



Hand Compactor



Roller

7.4

CHORUS RELOCATION ON SWANSON ST AND WYNDHAM ST:

A relocation of chorus communications cables at Swanson St was required as part of the SP2 works, however due to the condition and location of the existing ducts, a new design was required. These works now include trenching down Swanson St to an existing pit on Mills Lane. This trench will consist of the following dimensions: 

Length – 50m



Width – 1.0m



Depth – 1.5m

The existing chorus network at Wyndham St conflicts with the proposed pile alignment. A relocation of this network is therefore required. This includes the installation of new ducts across Wyndham St east and Albert St (south of Wyndham St), and also includes the installation of two new pits. The trench will consist of the same dimensions as noted above.

Machinery for the chorus relocation works at both Swanson St and Wyndham St will include the following: 

Saw Cutter



Vacuum Excavation Truck



Excavator (4T – 12T)



Jackhammer



Rock Breaker (for Albert St road crossing)



4-6 wheel trucks



Hand Compactor