27/08/2026
This image is a detailed 3D cross-section diagram of a Reinforced Concrete Cantilever Retaining Wall under construction.
Here is what it shows:
1. The Structure Itself:
It's an L-shaped retaining wall made of reinforced concrete. You can see the steel rebar cage inside before the concrete is fully poured.
C = 0.3m: The thickness of the wall crown (the top of the wall).
B = 4.00m: The total width of the foundation base.
P = 2.05m: The heel part of the footing that goes under the retained soil.
A = 1.35m: The main footing block where the worker is standing.
H = 1.5m: The total height / depth of the foundation footing.
0.6m: The thickness of the toe of the footing on the front side.
50m: The total length of the wall being measured.
Foundation Footing: The wide base that provides stability and prevents the wall from overturning.
2. The Soil and Backfill Layers (from top to bottom):
Gravel Wall / Red Rock: The top surface layer behind the wall, consisting of rocky, reddish fill material.
Natural Terrain: The original undisturbed ground behind the wall.
Between the natural terrain and the concrete wall, there is a vertical layer of rounded gravel/stones. This is a drainage filter layer that allows water to flow down freely without carrying soil particles.
3. The Drainage System - The most important part:
Retaining walls fail if water pressure builds up behind them. This design prevents that:
Subsurface Drainage Pipe: A large perforated blue pipe at the bottom of the gravel layer that collects groundwater.
Weephole Drain: A small pipe going through the concrete wall that lets the water collected by the subsurface pipe exit to the front. You can see water flowing out of it in the image.
4. The Construction Context:
A worker measuring the wall crown with a tape measure to check the 50m length.
In the background, there are excavators and bulldozers, indicating this is an active infrastructure project, like a road cut or hillside stabilization.
In short, the image explains how a modern retaining wall works: it holds back a large mass of earth (Natural Terrain + Red Rock) using a heavy L-shaped reinforced footing, while a built-in gravel and pipe drainage system prevents water pressure from destroying it.
