Appendix 541Subdivisions of Grade D Chalk by engineering behaviour
Suffix Typical discontinuity spacing (mm)
1 t 600
2 200
t
600
360
t
200
420
t
60
5 t
20Suff ix Engineering behaviour Dominant element Comminuted chalk Coarser fragments (%)
matrix (%)
m fine soil matrix approx 35 approx
65
c coarse soil clasts approx
35 approx 65
Subdivisions of Grades A to C chalk by discontinuity spacing