dear all.
i am now calculating on-bottom stability, and free-span caused by VIV as an assignment from my campus.
i have a basic enginering design data of some pipeline project with some met-ocean data on it.
but there are still many parameter that i don't understand of where should i get it.

1. how should i get the Us and Uc parameter?

the engineering met-ocean data of the given case study consist of:
wind speed: U60, U1;
wave height: significant & maximum wave height Hs and Hmax, significant & maximum wave periode Ts & Tmax, significant wave length Ls & Lmax;
wave steepness: significant steepness (H/L)s and maximum steepness (H/L)max;
current velocity: V0-V100 (0-100 is the percentage of sea depth).

if the Uc is from current velocity, should i choose the 100% depth or the 100% depth minus the radius of the pipe?
is there any option to calculate Us beside by using figure 3.2?
is the peak periode of design spctrum Tp the same as significant wave periode Ts?

2. for calculating concrete thickness by absolute lateral static stability:

to calculate V* by using equation 3.2 or 3.3 how to determine the velocity of reference height V(zr)? what is the reference height?
to calculate the passive resistance Fr, there are parameters like Ks or Kc, in equation 3.26 Kc=Su.D/Fc.
how to calculate Fc? should i do as describe in the equation of Fc=ws-Fz? should i substitute Fz with Fz*?

3. for calculating allowable free span based on DNV RP F105:

how can i get the water particle velocity Uw?
can some-one tell me simply how the work process to get the allowable free span by F105?

4. and for the overall calculation:

every criteria listed in RP F105 are "maximum" allowable, and "minimum" for F109. how to determine the optimal value for each criteria? if the criteria is ws+b/b>=1.1, the selected concrete thickness is when the ws+b/b exactly equal to 1.1 or what?

since i am a new member of this forum, i do apologize if i'm asking too much questions.