Soldier Piling Services
A soldier pile wall is an earth retaining structure formed from a row of bored piles. Compared with sheet piling, its advantage is durability: being reinforced concrete, the wall is generally used as a permanent structure, not merely temporary support during construction.
Conversely, where the site allows slope engineering at lower cost — an open cut at a safe batter, or temporary support using sheet piles — that route makes more sense. We say this plainly: soldier piling is chosen when the site simply does not leave room for a cheaper alternative.
Spaced or Interlocking
Soldier pile & secant pilePiles are set at a centre-to-centre spacing greater than their diameter, leaving a gap between them. Suitable where the soil is cohesive enough and the groundwater table sits below the excavation base.
Centre-to-centre spacing is set smaller than the pile diameter, so the piles cut into one another and leave no gap. Used when the wall must hold back water, or when the soil between piles cannot be relied on to stand alone.
In the interlocking arrangement piles are built alternately: primary piles first, then secondary piles bored so they cut into the primaries on either side.
On site, both arrangements are often called soldier piles. What decides the matter is not the term but the drawing: centre-to-centre spacing against pile diameter determines whether the wall leaves a gap.
Case Study: AIS Tunnel
Jakarta — 2019A tunnel linking two Australian Independent School buildings, passing beneath Jalan Pejaten Barat. We built the Ø 800 mm soldier pile wall retaining the excavation: 17 piles on the south side and 27 on the north, at 1,000 mm centres — leaving roughly 200 mm between piles, with the soil in between held by soil arching.
Cage length was 18.4 metres with an effective length of 17.1 metres, using two reinforcement types (10D25 and 15D25) with D13-175 ties. Pile heads were chipped to cut-off level, with bars projecting 1.3 metres into the capping beam that ties all piles together.
The site was tight and sat within a public road, with PLN medium- and high-voltage cables crossing the working area — so part of the excavation had to be done by hand. Structural design was by the project consultant; our role was executing the geotechnical works on site.
Our Soldier Piling Projects
Field track record
Discuss your requirements
Not sure which foundation method suits your site? Just describe the conditions — our engineering team is glad to help, with no obligation.
WhatsApp: +62 811-902-590Saturday 10:00–12:00
Closed on Sundays and public holidays
© 2026 PT Alpha Konstruksi Nusantara
Bored pile · Soldier pile · Secant pile