Shatter problem

Hi guys, I am contributing again with one issue I cannot solve for an hour already and totally dont understand what its going like this.

I have several curves and several intersecting curves in ghp. I want to shatter the smaller ones into segments in place where they are intersecting with long ones . I calculate exact intersection points and trying use shatter to do so but It is not helping at all.

any ideaa?? thanks in advance.

Martin.