Controlled blasting - North Sydney Council · Controlled blasting will reduce the time needed to...
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City & Southwest FACT SHEET AUGUST 2018 Controlled blasting Sydney Metro is Australia’s largest public transport project. It will transform Sydney, delivering more trains and faster services for customers across the network. John Holland CPB Ghella (JHCPBG) has been awarded the Metro tunnelling contract for Sydney Metro City & Southwest. With a new crossing under Sydney Harbour, the 15.5km twin rail tunnels will run from Chatswood, through the CBD and on to Sydenham. Complex underground structures will be built for six new metro railway stations at Crows Nest, Victoria Cross, Barangaroo, Martin Place, Pitt Street and Waterloo. Victoria Cross North site JHCPBG work at Victoria Cross includes building a station entrance at Victoria Cross North (VCN), on the corner of Miller and McLaren Streets. The station entrance will provide lift access to the station below. The main construction activity at the VCN site involves excavating a shaft 23 by 32 metres wide, by 45 metres deep, with excavation due to commence in September 2018. A large acoustic shed covering most of the site, including the shaft area, will be in place before excavation begins. JHCPBG has been considering different excavation methods including controlled blasting. The information in this fact sheet provides an overview of the controlled blasting methodology and addresses frequently asked questions. What is controlled blasting? Controlled blasting involves: The pre-planned and safe use of small charges to break up hard rock such as sandstone Removing rock in layers Pre-drilling the rock with a series of holes Loading the holes with small charges and other materials Electronically detonating the charges in a timed sequence, which results in the rock being broken up into small removable pieces. Why use controlled blasting at Victoria Cross North? Excavation using rock hammers has a high impact and longer duration. Hammering would occur 6.5 hours a day Monday to Friday and up to four hours on Saturdays. It would take approximately eight months to complete the shaft excavation using only this method. Controlled blasting will reduce the time needed to excavate the shaft by about 50 percent, meaning it will take three to four months to complete. Controlled blasting also reduces the impact of vibration as each controlled blast lasts for a maximum of ten seconds. Is blasting safe? Controlled blasting is strictly regulated by the Environment Protection Authority (EPA), Department of Planning and Environment and SafeWork NSW and is conducted to the highest safety standards e.g. Australian Standard AS2187. Controlled blasting is not new, and has been used successfully on projects around the world and in Australia, including on projects such as Westconnex (2018), Kempsey bypass (2014) Legacy Way Brisbane (2014), Airport Link Brisbane (2010) and the Clem 7 tunnel Brisbane (2010). JHCPBG will ensure that all project approvals are in place before controlled blasting is done. Other safety measures include: Strict controls and safety processes for each controlled blast including the safe transportation and storage of materials Controlled blast management specialists overseeing the process Compliance monitoring by an independent third party before and after each controlled blast.
Transcript of Controlled blasting - North Sydney Council · Controlled blasting will reduce the time needed to...
City & SouthwestFACT SHEET AUGUST 2018
Controlled blasting Sydney Metro is Australia’s largest public transport project. It will transform Sydney, delivering more trains and faster services for customers across the network.
John Holland CPB Ghella (JHCPBG) has been awarded the Metro tunnelling contract for Sydney Metro City & Southwest. With a new crossing under Sydney Harbour, the 15.5km twin rail tunnels will run from Chatswood, through the CBD and on to Sydenham. Complex underground structures will be built for six new metro railway stations at Crows Nest, Victoria Cross, Barangaroo, Martin Place, Pitt Street and Waterloo.
Victoria Cross North site JHCPBG work at Victoria Cross includes building a station entrance at Victoria Cross North (VCN), on the corner of Miller and McLaren Streets. The station entrance will provide lift access to the station below. The main construction activity at the VCN site involves excavating a shaft 23 by 32 metres wide, by 45 metres deep, with excavation due to commence in September 2018. A large acoustic shed covering most of the site, including the shaft area, will be in place before excavation begins.
JHCPBG has been considering different excavation methods including controlled blasting.
The information in this fact sheet provides an overview of the controlled blasting methodology and addresses frequently asked questions.
What is controlled blasting?Controlled blasting involves:
�� The pre-planned and safe use of small charges to breakup hard rock such as sandstone
�� Removing rock in layers
�� Pre-drilling the rock with a series of holes
�� Loading the holes with small charges and other materials
�� Electronically detonating the charges in a timedsequence, which results in the rock being brokenup into small removable pieces.
Why use controlled blasting at Victoria Cross North?Excavation using rock hammers has a high impact and longer duration. Hammering would occur 6.5 hours a day Monday to Friday and up to four hours on Saturdays. It would take approximately eight months to complete the shaft excavation using only this method.
Controlled blasting will reduce the time needed to excavate the shaft by about 50 percent, meaning it will take three to four months to complete. Controlled blasting also reduces the impact of vibration as each controlled blast lasts for a maximum of ten seconds.
Is blasting safe?Controlled blasting is strictly regulated by the Environment Protection Authority (EPA), Department of Planning and Environment and SafeWork NSW and is conducted to the highest safety standards e.g. Australian Standard AS2187.
Controlled blasting is not new, and has been used successfully on projects around the world and in Australia, including on projects such as Westconnex (2018), Kempsey bypass (2014) Legacy Way Brisbane (2014), Airport Link Brisbane (2010) and the Clem 7 tunnel Brisbane (2010).
JHCPBG will ensure that all project approvals are in place before controlled blasting is done.
Other safety measures include:
�� Strict controls and safety processes for eachcontrolled blast including the safe transportationand storage of materials
�� Controlled blast management specialists overseeingthe process
�� Compliance monitoring by an independent third partybefore and after each controlled blast.
City & Southwest
Contact usFor more information, enquiries or complaints please contact us at:
1800 171 386 24-hour community information line
sydneymetro.info
www.facebook.com/SydneyMetro
Sydney Metro City & Southwest PO Box K659, Haymarket NSW 1240
If you need an interpreter, call TIS National on 131 450 and ask them to call 1800 171 386
SMCSWTSE-JCG-SCN-SH-ADV-009012
Other work supporting controlled blastingBefore starting controlled blasting, the VCN shaft will be excavated to about nine metres below ground level using rock hammers. About 1–1.5 metres of rock will be left around the shaft walls. These measures will provide additional noise and vibration protection.
After the controlled blasts, excavated materials will be removed by road and the shaft walls will be trimmed (using rock breaking and sawing). Walls will be covered in sprayed concrete for support, and rock bolts drilled into the ground where required.
When will controlled blasting start? JHCPBG is proposing to do two small trial blasts in September/October 2018.
How many blasts will occur?There will be four or five additional blasts between October 2018 and January 2019.
When will blasts occur?JHCPBG is proposing to carry out all blasts on Saturdays during the day to reduce overall impacts. Blasts will not take place on consecutive Saturdays.
Will blasting be used to excavate the tunnels below houses/apartment block?Controlled blasting will only be used to excavate the shaft at VCN (see map).
How will I know about the timing of the controlled blasts?�� Community notifications one week before
�� Emails to registered stakeholders*
�� Signage around the worksite
�� SMS alerts
�� Siren warning immediately before individual controlled blasts
�� Information on project website sydneymetro.info
�� By contacting the project 24/7 information line 1800 171 386.
*Don’t forget to register your details to receive email updates and SMS alerts. Please send your details including your name, address, email and phone number to [email protected].
What can I expect during blasting?You will see signage around the VCN worksite in the week before a controlled blast event.
Roads and footpaths around the blast area on Miller and McLaren Streets will be closed for about 15 minutes during a controlled blast, which will last for less than ten seconds. Traffic controllers and site staff will be in place to ensure that no-one enters the exclusion zone.
A siren will sound immediately before each controlled blast.
What will I feel, see and hear? If you are within about 110 metres of the shaft you may hear a controlled blast. This can sound a bit like rumbling thunder. You may also feel some vibration, which can feel a bit like passing over a bumpy road in a car. You will not see the controlled blasts as they will take place within the acoustic shed.
Will I need to be relocated?There will be no need to leave your home or apartment during the blast events.
Will the controlled blast affect my children or any pets?While children are not expected to be affected, it is recommended that they remain inside during the controlled blasts as a precaution. It is also recommended to keep pets inside if possible.
Will it affect utilities?JHCPBG is working closely with utility providers. These providers are comfortable that the controlled blasts are very unlikely to interrupt their services.
I care for someone with special needs what do I need to do?Please contact the community relations team on 1800 171 386 to discuss your concerns.
UndercoverBlastArea
Shed Area
Site Area
The location of the shaft area to be excavated with controlled blasting at Victoria Cross Station North site
