Steel Sheet Pile Calculator
Perimeter over pile width gives the count, then length and tonnage.
Quick answer
With the default inputs: Supported perimeter 120 m · Pile length 12 m · Effective pile width 400 mm etc.Total sheet pile weight 282.2 t
Edit the inputs below to recalculate.Inputs
Result
Total sheet pile weight
282.2t
| Supported perimeter | 120.0m |
| Pile count | 300pcs |
| Pile length | 12.0m |
| Total pile length | 3600m |
| Weight per metre | 76.1kg/m |
| Net weight | 274.0t |
| Weight with waste | 282.2t |
| Steel per metre of perimeter | 2.35t/m |
| Waling length | 240m |
| Piles per metre | 2.50pcs/m |
Pile count is perimeter divided by effective pile width, rounded up. Interlocks chain one pile into the next, so the effective width is the perimeter each pile actually covers — 400 mm for Larsen SP-IV — not the flange width. Pile length is excavation depth plus embedment, with embedment usually 0.5-1.0 times the depth to mobilise passive resistance; too little and the toe kicks in, too much is wasteful and cannot be driven. This is a quantity take-off only: embedment, support levels and waling sizes must come from a sealed design covering overall stability, overturning, heave and piping. Hire is charged by tonnage and days, so allow 3-5% driving and extraction losses.
Formula
| Pile count | n = ⌈perimeter ÷ effective width⌉ |
| Total length | L = n × pile length |
| Net weight | G = L × weight per metre ÷ 1000 |
| With waste | G = G × (1 + waste) |
| Waling length | L = perimeter × waling rows |
A 120 m perimeter with 12 m Larsen SP-IV piles (400 mm wide, 76.1 kg/m), two waling rows and 3% waste: 300 piles, 3600 m total, 274.0 t net, 282.2 t with waste, 2.35 t per metre of wall and 240 m of waling.
How to work it out
- Pile count = supported perimeter ÷ effective pile width, rounded up. Interlocks chain pile to pile, so the effective width is the perimeter each one actually covers.
- Pile length = excavation depth + embedment. Embedment is typically 0.5-1.0 times the depth, at the higher end in soft ground or near existing structures.
- Total length = count × pile length; tonnage = total length × weight per metre ÷ 1000.
- Waling length = perimeter × number of waling rows, one ring per support level.
- Add 3-5% for corner piles that must be cut and welded, interlock repairs and damaged heads; take the upper figure on sites with many corners.
Where it goes wrong
- Using the flange width — Larsen SP-IV is 400 mm overall and covers 400 mm, but U and Z pairs need care: some systems quote per single pile and some per pair, where two 400 mm piles make an 800 mm wall.
- Fixing embedment at 6 m regardless — embedment follows the soil and depth; 6 m under a 12 m deep excavation in soft clay kicks in.
- Pricing piles only, without walings and struts — walings and internal bracing or anchors are half the system and omitting them badly understates the cost.
- Allowing 1% waste — every corner consumes a pile cut from a standard one, and corner-heavy sites reach 8%.
Material and cost
Larsen SP-IV hire 0.8-1.5 CNY/m per day (or 8-15 CNY/t per day), driving and extraction 60-120 CNY/m, transport 30-60 CNY/t. Purchase about 6000-9000 CNY/t. H-section walings 6-12 CNY/m per day.
On site
- Probe for obstructions first; boulders and old foundations stop the pile going down and stop it coming out, leaving it buried.
- Check interlock tightness after driving — leaking interlocks let water and sand through, so pair the wall with dewatering or a cut-off.
- Extract after backfilling and grout the voids immediately; open holes cause settlement of neighbouring ground.
Basis
- JGJ 120-2012 Technical specification for retaining and protection of excavations, Chapter 4
- GB 50202-2018 Code for acceptance of foundation construction, Chapter 7
- GB 50497-2019 Technical standard for monitoring of building excavations
FAQ
Why the effective width rather than the section width?
Sheet piles form a continuous wall by interlocking, and each pile covers the perimeter of its effective width. Larsen SP-IV is 400 mm overall and also 400 mm of covered wall, since the interlock sits at the edge. U and Z sections need care: some are quoted per single pile and some per pair, where two 400 mm piles make an 800 mm wall — 1.25 piles per metre. Always read the wall-width-per-pile column in the manufacturer table, not the flange dimension.
How deep should the piles go?
Typically 0.5-1.0 times the excavation depth, at the higher end for soft ground, adjacent structures or tight deflection limits. The embedded length mobilises passive resistance against the active pressure, and too little leads to toe kick-in, base heave (common in soft clay) or piping in saturated sand. All three need explicit checks, not a rule of thumb. Deep excavations also need struts or anchors, and the number of support levels sets the waling rows.
Hire or buy, and how much waste?
Hire for short jobs with standard sections such as Larsen SP-IV; buy for long jobs, special sections or repeated use across projects. Hire is charged per tonne per day on top of transport and the driving and extraction costs, which usually exceed the rent. Losses come from corner piles that must be cut and welded, torn interlocks, damaged heads and piles that cannot be extracted. Allow 3-5%, more where there are many corners. Piles left in the ground lose material and can obstruct neighbouring works, so hire contracts normally carry a penalty clause.
Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.