Dear Ridwan,
Attached herewith show the revised drawings to solve the
current site condition.
1.The way to fix the base of steel columns can be done by
adding chemical bolt M20 , see drawing of bolt detail(case 1&2)
2. Welding of columns and beam shall be kept and approved by CNS structural engineer.
No need to have bolt & nut. This 's caused by changing shape of roof to flat type.
The calculation is beinng done and will be sent to you tomorrow.
Best regards,
Phonthep C.