Geocell Retained Stepped Wall
Solution Introduction
Geocell-retained stepped walls are a flexible, eco-friendly slope protection solution that utilizes high-density polyethylene (HDPE) geocells as both the panel and reinforcement material. They are created by stacking geocells layer by layer and stepping them back, forming a gravity-fed or reinforced soil structure resembling steps.
Compared to traditional concrete retaining walls, this solution not only effectively reduces lateral earth pressure but also allows for complete greening of the wall surface, making it a commonly used technology in sponge city and ecological restoration projects.
Construction Specifications
1. Subgrade Preparation
Excavation: Excavate the foundation area according to the design elevation.
Compaction: Level and compact the subgrade soil to the required bearing capacity (95%standard Proctor density).
Base Layer: Lay a leveling pad of crushed stone or a non-woven geotextile as a separation layer.
2. Geocell Deployment & Anchoring
Expansion: Stretch the Geocell sections to their full dimensions. Use a frame or "stretcher" to ensure the cells are uniform and fully opened.
Anchoring: Secure the sections using J-pins or steel rebar anchors. For stepped walls, the initial sections must be anchored firmly into the foundation.
Connection: Connect adjacent Geocell sections using heavy-duty staples or specialized connectors (e.g., ATRA keys).
3. Filling Operations
Material Selection: Fill the cells with granular material (crushed stone/gravel) for drainage, or topsoil if the wall is intended for vegetation (green wall).
Overfilling: Overfill the cells by 25–50mm to allow for compaction settlement.
Mechanical Compaction: Use light vibratory equipment to compact the fill material within the cells.
4. Stepped Layering
Horizontal Setback: Place the next layer of Geocell on top of the compacted lower layer, moving it inward (away from the wall face) by the designed setback distance.
Interlocking: Ensure the layers are interlocked. In some designs, the upper layer is connected to the lower layer to increase shear resistance.
Horizontal Reinforcement: For high walls, lay a Biaxial or Triaxial Geogrid between specific Geocell layers, extending into the backfill to provide extra stability.
5. Backfill & Drainage System
Backfill Placement: As each layer of Geocell is filled, the area behind the wall must also be backfilled and compacted in lifts.
Internal Drainage: Install a Soft Permeable Pipe or a Composite Drainage Net at the rear of the Geocell structure to prevent hydrostatic pressure buildup.
6. Facing & Vegetation
Fascia Treatment: If using soil fill, the exposed "steps" of the Geocell can be hydroseeded or hand-planted.
Erosion Control: The Geocell walls naturally protect against surface erosion, but Erosion Control Mats can be used on the top step for added security.
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Working Principle
The core of this system lies in "lateral restraint."
Each cell acts like a miniature container, restricting the lateral displacement of the fill material, thereby significantly improving the overall load-bearing capacity and shear strength.
Face Units: The exposed outer layer of cells, typically filled with planting soil and sown with grass seed to form a green vegetation layer.
Setback: Each cell layer is offset backward relative to the layer below (typically with a slope between 1:0.3 and 1:1). This stepped design enhances the stability of the wall and provides a water receiving platform for plant growth.
Fill Material: The interior can be filled with excavated soil, gravel, or graded sand and gravel, reducing material transportation costs.
Connectors and Anchors: Specialized connecting fasteners (such as ATRA keys) are used to connect the cell sheets into a whole, and they are secured with U-shaped steel anchor rods.
Address
Production Center: Development Zone, Tai'an City, Shandong, China
Marketing Center: Ichi-no-Machihigashi, Sakai-ku, Sakai City, Osaka, Japan