Rotary Bored Piling

Current equipment capacity enables rotary bored piles to be advanced to depths of 45m at diameters of up to 2.5m. Piles of various diameters can also be advanced and supported with temporary or permanent casing. The largest of the rigs (Casagrande TRD100) has the unique ability to simultaneously advance piles with casing utilising Dual Rotary techniques.

Continuous Flight Auger Piling (CFA)

As an alternative to traditional pile construction methods, McMilan SDS have introduced Continuous Flight Auger Piles (CFA) to New Zealand. CFA piles offer a number of significant advantages to conventional bored and driven piles.

Piles are constructed by advancing continuous Hollow Flight Augers to target depth, enabling concrete to then be introduced under pressure whilst the augers are withdrawn and arisings removed. Upon auger withdrawal, reinforcing is then introduced into the pile.

The entire system is monitored electronically throughout the operation and real time data recorded and displayed on a monitor inside the drill rig. Real time monitoring allows the operator to control all aspects of the pile construction – for instance controlling the rate of auger withdrawal to ensure concrete placement exceeds the theoretical pile diameter. Once the pile is complete the data can be retrieved, analysed and a report produced for validation by the Client and / or Engineer.

CFA piles do not require temporary casing through wet and collapsing material, are relatively noise/vibration free and quick to install. Another siginificant advantage is the CFA piles can be installed into/through materials with artesian groundwater conditions without risk of external pile leakage, a particular concern in areas such as Christchurch and Wellington.

Contiguous and Secant Bored Pile Walls

Offering leading edge foundation and retention solutions, McMillan SDS offer considerable experience in both contiguous and secant (interlocking) piled walls. Constructed in-situ, walls can be reinforced to counter significant bending moments, overlapped to establish impermeable groundwater barriers and integrated into structures as load bearing elements.

Proven as a practical and cost effective alternative where noise, vibration and ground conditions are to onerous for sheet piling.

Ground Anchoring / Micro Piles

At the heart of foundation and retention solutions, McMillan SDS offer design and construction services for a variety of ground anchorage types. Integrating disciplines such as drilling, fabricating, installation and testing ensures a high level of quality control.

Anchors are designed, constructed and validated in accordance with industry standards providing Clients and Engineers with confidence in the final product. To install anchors through a wide variety of material types, specialist equipment and drilling methods have been developed. Crane mounted and portable anchor rigs are also available for difficult/limited access sites.

Driven Piling / Sheet Piling / Craneage

Offering all types of driving and vibrating piling methods. For bearing retaining purposes our 40ton Telescopic Crawler Crane provides access to even the most difficult sites.

Ground Improvement

Ground improvement techniques such as deep soil mixing, soil displacement / replacement and high pressure grouting are recent additions to the scope offered by McMillian SDS. Utilising the larger capacity drill rigs, ground improvements can be achieved to significant depths, treating large volumes of material with each pass of the tool. McMillan SDS are also experienced in high pressure grouting techniques such as as closure grouting with Tube And Machete (TAM) Grout Injection.