This project involved the demolition of 8 existing buildings on the former Gunns sawmill site in Smithton.

Key considerations relating to the risks associated with the demolition of the buildings:

• Large motorised mobile plant and machinery
• Existing services and plant (furnaces, substations, kilns)
• HAZMAT removal and disposal

Innovative thinking and planning for the project include the re-use of clean fill/rubble from the site to construct hard-stands for felled timber storage on a neighbouring property, along with fill for existing pits on-site. Scope of works included demolition of all buildings, services, structures and equipment that exist on the site to the top of the ground floor slab surface level or exterior surface.

Client	Saputo Dairy
Duration	6 months
Contract Value	$791,000

The demolition works at the Royal Hobart Hospital in Hobart’s CBD was part of the larger construction works undertaken by the John Holland / Fairbrother joint venture to replace the hospital’s B Block with a new K Block, while the hospital remained fully operational. Hazell Bros was awarded the subcontract tender for the demolition of B Block located in the northwest corner of the hospital complex. The project was successfully completed through in-depth staging that allowed machinery to reach the higher levels of the building’s “tower” by constructing a ramp comprised of debris from the lower levels.

Scope of works included:

• Design, engineer, supply, install/erect, certify, dismantle and removal of temporary works including façade propping/structural bracing/formwork, support and protection.
• Demolition of B Block’s “fan”, “tail” and “tower” structures, while causing minimal disruption to heritage-listed and operational areas of the hospital.
• Diversion of all hospital services (power, medical gases, water etc.)

Demolition of the existing Block B involved substantial technical, physical and logistical challenges that had to be overcome for successful project delivery.

The demolition work was completed within a live hospital environment which required:

• Patients to be decanted from Block B to a temporary building in the RHH footprint
• Noise attenuation and dissipation to minimise disturbance to operating theatres and laboratory areas that contain sensitive equipment (microscopes, etc.) susceptible to impacts from ground vibration.

Hazell Bros was a Category 2 Winner at the Tasmanian 2017 CCF Earth Awards for the Royal Hobart Hospital Redevelopment – Block B Demolition.

Client	John Holland Fairbrother Joint Venture
Duration	2016/2017
Contract Value	$5M

10 Murray St forms part of the Parliament Square precinct, with the project site bordered by Parliament House, Salamanca Building and 34 Davey St. Stage 2 of the Parliament Square Redevelopment involved demolition of the 13-storey 10 Murray St building, retentions of the 12 Murray St heritage facade, and demolition of the 12 Murray St building.

Due to the proximity of the works to neighbouring occupied office buildings and businesses, additional environmental considerations were adopted for the duration of the works including dust, noise and vibration monitoring. Specialised contractors were engaged to install monitors and track levels with additional noise monitoring conducted in sensitive areas.

Additionally, regular meetings were held with stakeholders to communicate where the work program and construction methods were presented to inform people of what they could expect in the progression of the works, how the dust, noise and vibration are being managed. This also provided a platform for Hazell Bros to understand what the stakeholders’ concerns were through project delivery.

The design maximised the footprint of the demolished 10 and 12 Murray St buildings presenting challenges in maintaining the structural stability of the surrounding buildings during project delivery. The construction required 800m3 of material to be excavated. Survey monitoring points were established on buildings adjacent to the site, including the maintained heritage façade, to measure any movement during excavation and construction of the retaining wall.

The 10 Murray St groundworks involved excavation of the site approximately 12m below existing ground level and 0.5m below sea level. This presented significant challenges with the ingress of groundwater during piling and excavation.

Construction of the retaining wall consisted of 172 contiguous bored piles and 140 ground anchors. The design and installation of the ground anchors had to consider the surrounding building structures and underground services, particularly where they were installed under the existing Murray St road.

Client	Citta Property Group
Duration	14 months
Contract Value	$14M

This project involved the demolition of the Jacksons building at 231-235 Wellington Street in Launceston.
Key considerations were given to mitigate the risks associated with the demolition of the buildings:

• Adjacent footpath pedestrian access – clearly delineated pedestrian detours with traffic controllers to guide people.
• Nearby hospital and other healthcare facilities – manage minimum dust and noise levels during the demolition by using hydraulic jaws (not breaker) to demolish, and ensure dust control with water sprayers.
• Adjacent dual traffic lanes and risk of demolition debris – inside lane closure and delineation with open-top shipping containers to stop and capture any demolition debris by using hydraulic jaws (not breaker).
• Nearby businesses and other buildings – use temporary protection to avoid any damage to the footpath and driveways.
• Interaction with live traffic – undertake main frontage demolition on weekends with less traffic
• Traffic management plan – dedicated entry and exit points to site for trucks.

The scope of works included the complete demolition of the concrete building, removal of steel roof trusses, excavation of footings and transportation/disposal of demolition waste.