## Design Parameters:

## Help

### Height of earth retained

*Symbol:* h

*Unit:* m

*Expected value:* design is economical for less than 10 m height of earth.

### Surcharge pressure

*Symbol:* w_{s}

*Unit:* kN/m^{2}

*Expected value:* can be 0

### Angle of internal friction of soil

*Symbol:* φ

*Unit:* degree (°)

*Expected value:* 20 - 40°

### Slope of backfill

*Symbol:* β

*Unit:* degree (°)

*Expected value:* 0-35°

### Unit weight of soil

*Symbol:* γ_{Soil}, γ_{e}

*Unit:* kN/m^{3}

*Expected value:* 14-22 kN/m^{3}

^{3}for clay to 22 kN/m

^{3}for gravels.

### Soil-wall interface frictiion

*Symbol:* δ

*Unit:* degree (°)

*Expected value:* 10-30°

### Unit weight of concrete

*Symbol:* γ_{concrete}, γ_{c}

*Unit:* kN/m^{3}

*Expected value:* 23-25 kN/m^{3}

^{3}.