Sako: Pressure built up in the coolant system when the car is hot is TOTALLY NORMAL. This is how all cars have been designed and it is the way it should be. Pressure will slowly release as the car cools down, but it could a while before it does. (few hours)
The shaking has nothing to do with your coolant pressure

Thanks guys for your help.Today finaly i solve the problem and the head gasket was replced by the mechanic and everything is ok now.