Using Piles To Mitigate Issues Of Building Near Sewer Pipes

Posted by: Steve Hitzman 10 years, 8 months ago

Many residential and commercial properties are located within close proximity to Water Corporation sewer pipes. (perhaps re phrase to include land shortage and increasing density and shrinking house blocks?)

If a structure is to be built within proximity to existing services such as sewer lines, in line with building codes, the foundations base must be installed a minimum of 600mm away and below the Zone of Influence as demonstrated below.

Zone of Influence

Under normal circumstances this could entail a substantial amount of earthworks and result in excessive costs to projects. One cost effective solution is to opt for deep foundations such as Piles.

There are different types of piles suited for particular situations. For general sandy conditions like those found across Perth, installation of standard Screwpiles may be adequate.

A Screwpile consists of a circular hollow shaft with a cutting helix at one end. Adopting a Screwpile option effectively transfers the proposed buildings loading down further into the ground and in this situation below the zone of influence to the sewer pipe.

Foundations near sewer pipe

Typically the length of Screwpiles for this application is 2 metres, however this length can increase to embed the helix below the zone of influence and accommodate deeper existing works.

For residential and commercial applications where loads are not expected to exceed 100kN per pile, the installation can be usually completed using an 8.5 tonne excavator. For higher loadings per pile a 25 tonne excavator may be required, resulting in turn to increases in site access width and height requirements.

Should you be looking at installing Screwpile at a current project or are interested in the advantage and applications of Screwpiles you can find out more information at www.screwpile.com.au