12d Model

I have an existing dxf file contours and I have create a tin by triangulation using 12d when I generated the contours from the tin result contours got bubbles and not smooth? Even I press remove bubbles in the option the result of the contours is not right? Is there another way of doing this?

I am new in 12d I have a question how will you combine or treat an intersection of 2 centrelines road alignment in computing the cut/fill volume?