Soldier Pile Contractor
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
Service Area
Greater Jakarta and beyond JavaWe are based in Bekasi Regency and work from Greater Jakarta through to islands beyond Java. Soldier pile walls are most often built on sites that adjoin existing buildings or a live road — conditions that call for work without vibration and without a sloped excavation.
How We Work Together
From soil data to completed excavationA boring log with groundwater readings, the planned excavation depth, a site layout, and the distance to surrounding buildings or roads.
Diameter, pile spacing, embedment and the need for propping are checked against site conditions. Deep excavations usually need extra support — struts off the structure, for instance — and that has to be settled early.
The scope is stated openly: number of piles, pile length, capping beam, who carries the testing, and what is excluded.
Piles are drilled and cast in a designed sequence with verticality controlled — in a line of piles, a single deviation shows immediately on the face of the wall.
Excavation proceeds layer by layer rather than straight to the base. Where neighbouring buildings are close, settlement markers and wall movement are monitored as the dig goes down.
What You Receive
More than a standing wallEvery pile in the wall carries its own record: actual depth, reinforcement, concrete volume and the soil encountered. On top of that, retaining wall work always comes with position data — as-built coordinates for each pile — because the accuracy of the wall line determines the working space left inside it.
Questions and Answers
The ones we are asked mostWhat is the difference between soldier, contiguous and secant piles?
All three are walls made of bored piles; the difference is the spacing. Soldier piles stand apart, contiguous piles touch, secant piles cut into each other and so form a water-tight wall.
Does a soldier pile wall hold back water?
No. Gaps between the piles let groundwater through. If the water table sits above the base of the excavation, the options are lowering it with dewatering or using a cut-off wall such as secant piles.
How close to a neighbouring building can you work?
Because the piles are drilled rather than driven, work can be carried out very close to existing buildings. What usually sets the distance is physical room for the plant and the property boundary, not vibration.
Does the wall need extra support?
It depends on the depth of the excavation and the earth pressure. Shallow digs are often held by the wall alone as a cantilever; deeper ones normally need support. The structural designer decides this, and it must be settled before excavation starts — not after the wall moves.
Is the wall removed afterwards?
Usually not. It stays in the ground and is often used as part of the basement structure or as permanent protection behind the structural wall.
What diameters are typical?
For excavation retention, generally Ø 600 to Ø 1,000 mm depending on depth and earth pressure. On the AIS Tunnel project in Jakarta we used Ø 800 mm piles 19 metres deep.
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: +62 811-902-590 Download Company Profile PDF · 3 MBSaturday 10:00–12:00 WIB
Closed on Sundays and public holidays