This is not a complicated issue. You put the trash where he cannot get it, inside a pantry or out in the garage. If you have a trash can that you are forced to step on a foot pedal to lift the lid that will help, however, most big dogs will simply knock the can over, what you do is purchase weights, the round kind that go on the end of a bar for weight lifters, you place the weights inside the can, 10-20lbs will do, this holds the can in place and makes it very hard for the dog to move or tip over, so unless he knows how to lift the lid the garbage is difficult to get to. Another method is to keep the garbage can behind a closed door if possible. If you live in an apt and putting in the garage is also out of the question I suggest purchasing a square/rectangular lidded can that has the foot pedal to operate (see second link), then purchase an alarm that you place on sliding glass doors one that sticks on that has two parts to it one part goes on the lid the other on the can so that when the connection is broken a very loud piercing screech is emitted (see first link), this noise alone will scare your dog into leaving the trash alone, when you are home the alarm can be switched off, you just need to set it when you leave. I'm not sure that once the connection is re-established (your dog drops the lid) if the noise stops so you will have to test this out. This alarm can be purchased in any hardware store and is very cheap and uses double sided tape to install.
If you cannot hide your trash then all you can do is deter your dog from wanting to raid it by making it unpleasant when he does, otherwise trash raiding is a self rewarding behavior and very difficult to stop.