Wall Types
- Segmental Block (SRW): Modular concrete blocks with interlocking features; ideal with geogrid for taller walls.
- Timber: Economical for shorter heights; requires careful drainage to prevent rot and failure.
- Boulder/Natural Stone: Durable and aesthetic; needs proper base and drainage, especially with clay soils.
Key Design Considerations
- Base Preparation: Excavate to firm subgrade, install compacted crushed stone base (often 6–12 inches depending on loading).
- Drainage: Provide gravel backfill, perforated drain pipe at heel elevation, and weep holes or outlets.
- Reinforcement: Use geogrid layers per manufacturer specs; longer grids on taller walls and in poor soils.
- Setback & Batter: Properly slope the wall face and maintain setbacks to resist lateral earth pressures.
Technical Diagrams
Wall Cross-Section
Install clean gravel backfill and a perforated drain behind the wall; provide outlets to relieve water pressure.
Geogrid Reinforcement
Use multiple geogrid layers at specified elevations; grid length increases with wall height and soil conditions.
Drainage Path
Backfill directs water to the drain pipe, which discharges through outlets to relieve hydrostatic pressure.
Construction Steps
- Excavate & Prepare Subgrade: Strip organics and shape to firm, level base.
- Install Base: Place crusher run/DGA in lifts and compact; verify level.
- Set First Course: Level, align, and backfill as you go.
- Drainage: Install perforated pipe at heel elevation with clean gravel backfill.
- Reinforce: Place geogrid per specs; compact backfill to required density.
- Finish: Cap blocks (if required), grade surface, and stabilize outlets.