Assalamoalaikum to all members!
fisrt of all my apologies for any sort of mistake, this is my first post in this form.
i am currently working as a site engineer at a consultant, working for C & W Pak. the project, my consultant doing is, the Modeling of the Earth quick effected College located at Gul Abad, Dir lower. the zone is 3. the soil is sandy soil having boulders at the depth of 8 feet below. what kind of soil it is? i have noticed that the ties spacing all over the height of the columns according to structure engineer is 2.5" c/c. isn't it very low spacing. according to ACI 318-05 what should be the minimum spacing between the ties? the longitudinal reinforcement in the columns are 8 #6 bars. (i am fresh civil engineer having no experience on site).