How to define soil properties based on friction factor and mobelisation distance ?

I have a pipeline on the seabed and only friction factors and mobilisation distance to define soil properties. 

My values are :

SubmergedWeight = 390N/m

Friction_axial = 0.15

Mobilisation_distance_axial = 30mm

Friction_lateral = 0.40

Mobilisation_distance_lateral = 780mm

I use Calculation Method "User" and calculate P1 according to :

P1 = friction_factor x SubmergedWeight (N/m)

then I calculate k1: 

k1 = P1 (N/mm)/ mobilsation distance (mm)

I have the following results :

P1_axial = 58.5 N/m

P1_lat = 156 N/m

k1_axial = 0.00195 N/mm/mm

k1_lat = 0.0002 N/mm/mm

And for Trans Vertical Downward I consider 

P1 = SubmergedWeight

k1 = SubW/pipeline settlment.

What do you think ?
I have the feeling my values, especially for k1 are really low. 
Could you please help me to understand the proper way to define my soil ?