PECK토압을 STEP3에서 적용하고 싶은데

K,a,c 값을 어떻게 적용해야 하는지요?

SOIL 1 매립층
2.00 1.7 0.8 0 27 1500
2 붕적층
6.50 1.9 1.0 0 32 2500
3 풍화토
14.50 2.0 1.1 1.5 33 3000

VWALL 1 6.69 0.01348 0.000215 21000000 2 0.915 0.305

STRUT 1 1.29 0.01348 8.10 3 6

DIVISION 0.5

STEP 1 EXCAVATION TO 1.79
MINIMUM-ACTIVE 0.5
SURCHARGE 1.0
RANKINE 1.0
SLOPE 5
ITERATION 10 0.1
EXCAVATION 1.79

STEP 2 STURT 1 & EXCAV TO 3.69
CONSTRUCTION STRUT 1
EXCAVATION 3.69
INSERTION CHECK
GROUND SETTLEMENT

STEP 3 PECK CHECK
PECK 0.65 0 0.5

END