As anyone who has watched the Jurassic Park series knows, Hollywood likes to exaggerate a bit when it comes to dinosaurs and their scientific accuracy. Many facts are fairly easy to prove right or wrong by looking at skeletons and other fossils. However, others are a bit harder to prove right or wrong. One of these Hollywood "dinotropes" is the ground literally trembling before the dinosaurs' feet. The answer may seem simple because of the sheer mass of some dinosaurs, and some large animals (rhinos and even running race horses) today can even cause the ground to tremble slightly. However, elephants are known to be able to move very softly, even sneaking up on people, and it would also make sense that large predatory dinosaurs would want to be stealthy when approaching prey. My question, put simply, is this: would large dinosaurs (ie: Tyrannosaurus sized or larger) shake the ground as they walked and moved around?
Yes, they would, when they want to.
Each animal has different modes of movement available to it, ranging from a slow, quiet sneak to full-blown sprint. Each mode has its own advantages and is used as appropriate. A sufficiently large animal that at the moment does not care about moving quietly can certainly cause the ground to shake, depending on how heavy it is, how fast it's moving, and the type of ground it's moving on. For example, an African Elephant can move at top speeds of 40 km/h (25 mph), which is about the same as the fastest humans, but of course they are also among the heaviest animals on land.
Is it ever that simple?
Your average large dinosaur is going to be much more considerate of its joints and feet than fiction would have them. It's more likely to move with the silence of the elephants than with the thunder of a horse race, if only to reduce the shock to the body from every step taken.
A T-rex is only slightly larger than an elephant but its bone structure is far different being bipedal as opposed to quadropedal and the elephant is known to use its trunk to help detect its surroundings enabling a much smoother ability to walk tham some other quadropeds.The angle of the legs would allow for much more force to be applied to the ground for forward motions and stopping or for smashing.given the smaller sized arms its likely this large creature would use its leggs as a primary force for attacking with much as a chicken will often use its legs to attack. As stated you are probably right in the assumption that movies greatly exagerate this but it could be rather viable that these types would be likely to make a substantial vibration. for instance if you were to go out in the country and stand next to a railroad with a train going at full speed with empty cars the vibrations would be almost perfectly comparable to the effect the dinosaur would have on the ground...speciffically because the estimated weight of a T-rex is 9 tonnes and a train car about 20 tonnes across 2axels about the size of their foot area. The vibration caused at this point is due to the many minor differences in rails allignments but is only considering mere inches of up and down impact so one could reasonably presume a similar impact would be nearly standard for casual motion of this type of creature. in a full on sprint or large jump this could be much more prominent. note that a train is possible to be heard in an unobstructed environment for as far away as 5miles...and if you are acustomed to a life of absolute silence (unlike most people today between tv and internet) you can likely even feel some minor vibrations from at least a mile away.
short answer no, vibration has more to do with gait than size. Animals minimize the shock to their own body by not stamping around without good reason, the bigger the animal is the less shock it wants so the smoother its gait should be, the largest dino's have even shock absorbing pads like elephants on the load bearing limbs. On the other hand running dinosaurs might well generate substantial vibrations just as modern mammals do when they run.