Secant PilingBasement Excavation

Pelican House, Mespil Road

When Hegarty Demolition was contracted to demolish the Pelican House building on Mespil Road, the company’s technical knowledge saved its client both time and money.

The building was a six-storey reinforced concrete structure with pre-cast cladding on the front façade. Its overall height of 20m allowed the use of 35 tonne excavator fitted with a “long reach” (22m) demolition arm, which is proven to be the most cost-effective method of demolition where adequate space is available to operate this size of equipment. Following “soft-stripping” of the building, this method provided an efficient means of breaking out all the concrete elements and processing the materials for recycling.

The hydraulic concrete pulveriser used with the demolition arm munched the reinforced concrete elements – slabs, beams & columns – in pre-programmed sequence from the top to the bottom of the building. This allowed the separation of re-bar and the salvage of reinforcing steel as work progressed.

Following demolition and site clearance Hegarty Demolition Ltd. proceeded to carry out:

  • Deep dig excavation for this three storey basement, where 66,000m3 of soil was removed to a pre-planned tiered schedule, and removed offsite for disposal. Also included was the removal of 12,000m3 of rock.
  • The design, erection, maintenance and removal of a temporary support system to support the site along the busy Mespil Road and adjoining office buildings to a depth of 8.5m.
  • The management, pumping and treatment of the very heavy ground water found on site.

This project was completed safely and efficiently in the most cost-efficient and environmentally-friendly manner possible.