That's true. I've seen them all over north western China. although I know what the true purpose of them are. The pillar look pretty dense to me, so I'm not what to think about "avoid interfering". I suspect they are used to keep the rails level since the network goes thru a pretty wide range of elevation.
This is correct. Much of china is mountainous, so pillaring and tunneling are quite common to get the straightness needed for HSR. They also need to skip over urban areas sometimes, but that is more about traffic.
