Z Type Steel Sheet Piles
Z type sheet piles are long structural steel sections with Z-shaped profiles and continuous interlocks, forming a high-performance retaining wall system. Due to their higher section modulus and efficient load transfer, they are widely used in port construction, deep foundations, and combined wall systems.
Structural Characteristics & Performance
Hot rolled Z sheet piles feature a continuous web and interlocks symmetrically positioned on both sides of the neutral axis, significantly improving bending resistance and structural efficiency.
- Higher section modulus → stronger bending capacity
- Better load transfer → pressure distributed to surrounding soil
- Efficient material utilization → lower weight under same performance
- Larger effective width → fewer piles required per wall
👉 Compared to U type sheet piles:
Z profiles provide lower weight per m² when modulus is similar, reducing material and installation costs.
Manufacturing Technology (Hot Rolled vs Cold Formed)
Hot rolled Z sheet piles are produced at high temperatures, allowing:More precise and tighter interlocks，Better performance in hard soil conditions，Higher water tightness in retaining systems.
👉 Key difference:
- Hot rolled → tight interlocks, heavy-duty applications
- Cold formed → flexible dimensions, light-duty applications
Product System & Standards
Common hot rolled Z sheet pile systems include:AZ Sheet Piles，PZ / PZC Sheet Piles，OZ Sheet Piles，OZ Sheet Piles.
👉 Standard: EN 10248 (Part 1 & 2) widely used.👉 Interlock Types:Ball type (mainly USA)，Socket type (Europe & most global markets).
Technical Parameter Table
| Section | Width (mm) | Height (mm) | Thickness (mm) | Weight (kg/m) | Inertia (cm⁴/m) | Section Modulus (cm³/m) |
|---|
| GHZ 12-770 | 770 | 344 | 8.5 | 72.6 | 21440 | 1255 |
| GHZ 14-770 | 770 | 345 | 9.5 | 79.5 | 23310 | 1365 |
| GHZ 13-700 | 700 | 315 | 9.5 | 74.0 | 20550 | 1315 |
| GHZ 18-700 | 700 | 420 | 9.0 | 76.5 | 37810 | 1810 |
| GHZ 20-800 | 800 | 450 | 9.5 | 88.6 | 45060 | 2010 |
| GHZ 25-800 | 800 | 475 | 12.5 | 102.6 | 59420 | 2510 |
| GHZ 30-750 | 750 | 510 | 13.0 | 108.8 | 76680 | 3015 |
| GHZ 36-700N | 700 | 499 | 15.0 | 118.6 | 89620 | 3600 |
| GHZ 44-700N | 700 | 500 | 19.0 | 149.9 | 110160 | 4415 |
| GHZ 52-700 | 700 | 505 | 24.0 | 174.1 | 130150 | 5165 |
Corrosion Protection System
To ensure long service life, various protection methods are applied:
- Increased section thickness → corrosion allowance
- High strength steel grades (S355GP / S390GP / S430GP) → extended lifespan
- Coating systems (Epoxy / Jotun / Hempel / Interzone) → 20+ years protection
- Cathodic protection → sacrificial anodes or impressed current
- Concrete encasement → splash and tidal zone protection
👉 Design must consider:
- Marine zones (tidal, splash, immersion)
- Soil and groundwater corrosion
Engineering Design Considerations
Performance of sheet pile walls depends on:
- Section modulus
- Steel grade
- Soil conditions
👉 Z sheet piles are preferred for heavy-duty and long-term projects due to:
- Higher structural efficiency
- Better water tightness
- Suitability for complex foundation systems
