Hello and thank you for using JustAnswer. My name is XXXXX XXXXX I will do my best to help you with your Chevy problem.
First start by checking the FP/INJ fuse in the dash fuse panel. If this fuse is good then check the fuel pump relay in the underhood fuse panel. Place your hand on the relay and have someone else turn the key on. You should feel the relay click on and then click off again about 2 seconds later. Let me know what you find.
I know that you said that the relay was new, just wanted to make sure the relay was getting the proper signal from the computer and turning on. If the relay is turning on, you will need to test for power on the gray wire at the fuel pump connector under the car. Again, this wire will have power for two seconds when the key is turned on. Also check the ground for the fuel pump. This is ground G304. G304 is located near the drivers seat. Remove the sill plate and pull back the carpet to expose this ground. Also check for any damage to the fuel pump wiring harness from the collision.