What does NEC require for strapping down conduit and wire here?
2014 NEC Article 352.30(A) states that PVC conduit should be supported within 3' of each outlet box, disconnect, panel, etc. That also Includes strapping the 90% ells you have installed. I can see that you have installed expansion joints so the strap has to go above the joint to allow the joint to expand with the grade. 

Also the ground wire is attached above and below the expansion joint binding the joint and connection. You would be better off attaching the ground to the building instead of the conduit as the comments have already indicated.

Good luck.