Do not change each span, it is unnecessary. Small groups of trusses are assembled on ground as one module, then lifted into place and secured to the posts and to adjacent modules. What is the magnitude of load you need to resist and reactivity of the soil. If you need grade beams, you need piles. Grade beam design I assume you are placing grade beams over pile.
Grade beam design Grade beam design I'm having a problem on a certain project site because it is swampy do you have any good reference for Grade beam or tie beam design?
Strip footings are used to support walls bearing on soil, unless that wall is also being supported on pile, then the wall sits on a grade beam. Defense manufacturing is all about project manufacturing and project accounting. Design of grade beams is no different than design of any concrete beam except that top and bottom reinforcement is normally continuous with laps of bottom steel at piles and top steel at midspan. What I have done in the past is use collapsible cardboard void formers under the slab as sacrificial formwork. That way if you have a soft spot somewhere along your foundation it will bridge over it. Try to have the geotechnical engineer give you a prescription for the pile designs such as diameter, reinforcement, and spacing.