Fairly standard, as far as these types of novels go. The fallen woman is morally unimpeachable - getting the reader on her side and thinking that maybe, just maybe, one sexual mistake oughtn't condemn a woman forever - but she still has to die to satisfy Victorian bloodthirsty sensibilities. 
 Then again, we don't read Victorian novels when we want our plots to be ground breaking. 
 I enjoyed the juxtaposition between Angel Clare's sexual indiscretions to Tess's. As she says, they are truly the same, and yet he gets to live while she must die. But the point is still made. And, at least, Alec d'Urberville is suitably punished. 
 I was interested by the repetition of the word "mechanical" in descriptions of Tess. I'm not sure what it means, but it appeared frequently enough that it must mean something. I'm sure someone, somewhere, has written a dissertation on it.