What is a Combi Wall?
A Combi-Wall (or Combined Wall) is a retaining/supporting structure system, it is composed of load-bearing piles (King Pile or similar heavy beam/pipe piles/Z and U Piles) with intermediate sheet piles, and connectors (welded or interlocking) to form a continuous wall, which has higher load-bearing capacity and higher stiffness than ordinary sheet pile walls.
Traditional and most widely used combi wall systems are HZ and OZ series, and a series of combi wall types has been developed based on the different combinations of sheet pile types. Combined walls have extremely high cross-sectional properties and are widely used in port/terminal construction and shipyard construction, where long piles and high section modulus steel sheet pile retaining walls are required.
Combi Wall System Performance: Properties (section modulus, moment of inertia, etc.) are measured per foot, calculated from the center of one king pile to the center of another.
Basic Structure of Combi Wall
- King Piles: Core load-bearing members, typically large wide-flange beams (WF beams) or steel pipes.
- Sheet Piles: Intermediary sheet piles placed between king piles, primarily for soil retention and with minimal contribution to structural performance.
- Interlock Connectors: Key components that connect sheet piles and king piles to form a single structure through welding.
HZZ Combi Wall Solution
HZZ Combi Wall is composed of HZZ beam (king pile) and zz series sheet piles, it is designed as the next-generation upgrade to the HZ combi-wall system. It addresses the weight, manufacturing, and flexibility challenges of traditional HZ combi-wall systems through direct-attach flange technology. HZ and HZZ combi walls serve similar purposes, HZZ serie is lighter, more efficient, and more customizable.
Hot Rolled HZZ Beam
HZZ Beams are custom-hot rolled to incorporate an interlock on both sides of the flange hence eliminating the need for any additional interlocks or grooves in the flange. A built up beam consisting of a Web and a Bottom Flange undergoes full penetration weld to form an entire H Section. The complete beams form a rigid King Pile which serves as the main wall of the structure resisting the load and surcharges behind the wall it retains.
HZZ Beam Design and Advantage
Choose HZZ Combi Wall can bring you many benefits, it is is better choice considering the cost control, eliminating 2, 4, or 6 connectors can reduce the load per beam by up to 40 lbs/ft, eliminate fabrication, and shorten lead times. In terms of operability, high-modulus wall beams can be constructed in lengths up to 100 feet and driven to depths of 50 feet or more.
HZZ Beam and flange design is the key technology upgrade of HZ combi wall, which is featured with a bulge in the flange center, it has the following advantages:
- Pushes the web-flange connection out of the xy plane, resolving the issue of welds located in the shear axis;
- Provides beam strength to resist transverse stresses in the same manner as flange-web transitions in hot-rolled beams or hot-rolled sheet piles;
- Provides excellent surface area for automated full penetration welds.
HZZ Beam Flange Dimension
AGICO sells HZZ steel sheet piles systems based on the hot rolled H steel beam with full pen weld technology, which is a better alternative option of HZ combi wall, customers can have more flexible designs of piling project at a much lower cost.
| HZZ FLANGE PROPERTIES | |||
|---|---|---|---|
| Section | Width (w) | Weight (m) | Flange (tf) |
| mm (in) | kg/m ibs/ft | mm (in) | |
| ZZF-23 | 527 | 124.8 | 23 |
| 20.75 | 83.87 | 0.906 | |
| ZZF-30 | 527 | 148.3 | 30 |
| 20.75 | 99.66 | 1.181 | |
| ZZF-40 | 527 | 175.8 | 40 |
| 20.75 | 118.15 | 1.575 | |
Note: When selecting sheet pile types for projects, it's essential to consult the specific standard's detailed parameter tables and compare key data such as section modulus, moment of inertia, weight per meter, and interlock form to ensure engineering safety.
HZZ Beam Specifications
| HZZ BEAM PROPERTIES | Per Single Section | Coating Area | |||||||
|---|---|---|---|---|---|---|---|---|---|
| HZZ Beam Model | Height (h) | Height (h) | Thick (h) | Cross Sec Area (a) | Weight (m) | Elastic Modulus (y-y) | Moment of Inertia (y-y) | Waterside Surface (A’) | Landside Surface (A”) |
| mm | mm | mm | cm2 | kg/m | cm4 | cm4 | m2/m | m2/m | |
| (in) | (in) | (in) | (in2) | (Ibslft) | (in4) | (in4) | (ft7ft) | (ft2/ft) | |
| HZZ 2323A | 780 | 610 | 14 | 403.5 | 316.8 | 11235 | 437.041 | 0.58 | 2.91 |
| 30.70 | 24.00 | 0.55 | 62.5 | 212.9 | 686 | 10,500 | 1.89 | 9.53 | |
| HZZ 2323B | 860 | 690 | 15 | 414.7 | 325.6 | 12.712 | 545.379 | 0.58 | 3.07 |
| 33.90 | 2720 | 0.59 | 64.3 | 218.8 | 776 | 13,103 | 1.89 | 10.06 | |
| HZZ 2323C | 940 | 770 | 15 | 433.7 | 340.4 | 14,303 | 670,789 | 0.58 | 323 |
| 37.00 | 30.30 | 0.59 | 672 | 228.8 | 873 | 16,116 | 1.89 | 10.58 | |
| HZZ 2323D | 1000 | 840 | 15 | 4432 | 347.9 | 15,541 | 778,350 | 0.58 | 3.35 |
| 39.40 | 33.10 | 0.59 | 68.7 | 233.8 | 948 | 18,700 | 1.89 | 11.00 | |
| HZZ 2323E | 1060 | 900 | 16 | 4612 | 362.1 | 16,840 | 893,968 | 0.58 | 3.47 |
| 41.70 | 35.40 | 0.63 | 71.5 | 243.3 | 1,028 | 21,478 | 1.89 | 11.39 | |
| HZZ 3023A | 980 | 810 | 16 | 477.8 | 375.1 | 15.515 | 804.737 | 0.58 | 3.30 |
| 38.60 | 31.90 | 0.63 | 74.1 | 252.1 | 947 | 19,334 | 1.89 | 10.83 | |
| HZZ 3023B | 1060 | 890 | 17 | 499.6 | 3922 | 17277 | 967,185 | 0.58 | 3.46 |
| 41.70 | 35.00 | 0.67 | 77.4 | 263.5 | 1,054 | 23,237 | 1.89 | 11.36 | |
| HZZ 3023C | 1092 | 932.2 | 18 | 523.9 | 411.2 | 18.246 | 1.050.707 | 0.58 | 3.55 |
| 43.00 | 36.70 | 0.71 | 812 | 276.3 | 1,113 | 25243 | 1.89 | 11.63 | |
| HZZ 3023D | 1160 | 990 | 19 | 536.6 | 4212 | 19,717 | 1,203,656 | 0.58 | 3.66 |
| 45.70 | 39.00 | 0.75 | 83.2 | 283.0 | 1,203 | 28,918 | 1.89 | 12.01 | |
| HZZ 4023A | 980 | 810 | 18 | 529.3 | 415.5 | 16,098 | 882,041 | 0.57 | 3.30 |
| 38.60 | 31.90 | 0.71 | 82.0 | 2792 | 982 | 21,191 | 1.87 | 10.83 | |
| HZZ 4023B | 1060 | 890 | 19 | 552.6 | 433.8 | 17,959 | 1,059,814 | 0.57 | 3.46 |
| 41.70 | 35.00 | 0.75 | 85.7 | 291.5 | 1,096 | 25,462 | 1.87 | 11.36 | |
| HZZ 4023C | 1092 | 932.2 | 21 | 577.3 | 4532 | 18,959 | 1,147,310 | 0.57 | 3.55 |
| 43.00 | 36.70 | 0.83 | 89.5 | 304.5 | 1.157 | 27.564 | 1.87 | 11.63 | |
| HZZ 4023D | 1160 | 990 | 21 | 591.6 | 464.4 | 20,546 | 1,318215 | 0.57 | 3.66 |
| 45.70 | 39.00 | 0.83 | 91.7 | 312.1 | 1,254 | 31,670 | 1.87 | 12.01 | |
| HZZ 4030A | 980 | 810 | 18 | 559.3 | 439.0 | 18,494 | 962,364 | 0.57 | 3.30 |
| 38.60 | 31.90 | 0.71 | 86.7 | 295.0 | 1,129 | 23,121 | 1.87 | 10.82 | |
| HZZ 4030B | 1060 | 890 | 19 | 582.6 | 457.4 | 20,542 | 1,153,584 | 0.57 | 3.46 |
| 41.70 | 35.00 | 0.75 | 90.3 | 307.3 | 1,254 | 27,715 | 1.87 | 11.35 | |
| HZZ 4030C | 1092 | 932.2 | 21 | 607.5 | 476.9 | 21,616 | 1248,176 | 0.57 | 3.54 |
| 43.00 | 36.70 | 0.83 | 942 | 320.4 | 1,319 | 29,988 | 1.87 | 11.62 | |
| HZZ 4030D | 1160 | 990 | 21 | 621.6 | 488.0 | 23,350 | 1,429,957 | 0.57 | 3.66 |
| 45.70 | 39.00 | 0.83 | 96.4 | 327.9 | 1424.9 | 34,355 | 1.87 | 12.00 | |
3 Benifites of HZZ Combi Wall System
Reduced Cost and Weight: Eliminating heavy welded connectors reduces weight by up to 40 lb/ft per beam, saving manufacturing costs.
Improved Reliability: Interlocking becomes an integral part of the beam, rather than a fragile, added component, resulting in improved actuation performance.
Customizability: Different flange thicknesses can be selected for different sides of the beam (e.g., waterside and soilside), achieving customized weight efficiency and corrosion resistance without compromising structural integrity.
Comparison of Traditional HZ and HZZ Combi Wall System
Revolutionary Installation Innovations of the HZZ System:
The HZZ beam’s technical principle: A unique structure with a drop-down nose and Larsen lock, formed directly on the flange of a hot-rolled H-beam, enables direct interlocking of sheet piles and main piles. This technology, known as the HZZ system’s direct-connect flange technology, eliminates the traditional welded interlocking connectors, which means the HZZ combi wall system installation is weld-free.
Choose HZZ Combi Wall For Unlimited Options
- HZ System – 100 Options: The most popular traditional combi wall systems such as HZ, offer limited configurations through a fixed product catalog (e.g., 11 beam types + 4 sheet pile types, ≈ over 100 options).
- The HZZ system – unlimited Options: It is no longer limited to pre-rolled beam models and connector counts. Its hot-rolling process allows for an unlimited number of combinations of section height, web thickness, and flange dimensions, making it the world’s first high-modulus wall system that can be fully customized to specific project requirements.
HZZ Combi Wall System Design Examples
