DISTANCE FROM THE FACE OF THE WALL TO THE BACK OF THE EXCAVATION

NO FENCE OR WIND PERMEABLE FENCE AT THE FACE

WALL HEIGHT
TOTAL WIDTH AT BASE OF WALL (B) mm
(H) mm
EMBANKMENT MATERIAL

STIFF CLAY
SAND
GRAVEL
ROCK
500
600
400
350
280
1000
850
600
550
440
1500
1150
800
750
600
2000
1400
1050
950
750
2500
1650
1250
1150
910
3000
1950
1500
1350
1040
3500
2200
1700
1550
1255
4000
2450
1900
1750
1400
4500
2700
2150
1950
1540
5000
3000
2350
2150
1700
5500
3250
2600
2350
1900
6000
3500
2800
2550
2015
 

WIND IMPERMEABLE FENCE AT THE FACE

WALL HEIGHT
TOTAL WIDTH AT BASE OF WALL (B) mm
(H) mm
EMBANKMENT MATERIAL

STIFF CLAY
SAND
GRAVEL
ROCK
500
600
400
350
280
1000
850
600
550
440
1500
1350
1250
1200
1150
2000
1550
1350
1300
1250
2500
1750
1500
1450
1400
3000
2000
1700
1600
1500
3500
2250
1850
1750
1255
4000
2500
2050
1900
1800
4500
2750
2250
2100
2000
5000
3050
2450
2250
2050
5500
3300
2650
2450
2250
6000
3550
2850
2600
2400

The above dimensions are based on the following:
Characteristics of Clay: Thi = 25o;   Density = 20 kN/m2;   Cohesion (c) = 75 kPa
Characteristics of Sand: Thi = 30o;   Density = 20 kN/m2;   Cohesion (c) = 0 kPa
Characteristics of gravel: Thi = 35o;   Density = 19 kN/m2;   Cohesion (c) = 0 kPa
Characteristics of Rock: Thi = 45o;   Density = 20 kN/m2;   Cohesion (c) = 75 kPa;   Ka = 0.18
Live load = 5 kPa;   5% maximum backfill slope
Fence: 1.8m high to AS1170 wind loads for a wind impermeable fence.
For walls up to 1 metre high the fence post is concreted into a post hole before wall construction. The fence post passes through the empty block cavities.
The width of RETAIN! will increase for higher surcharges