First, I think both spouses need to WANT to have a happy marriage. They need to communicate effectively. They need to have the same short and long term goals. They need to learn to live unselfishly. They need to learn to not take advantage of their spouses weaknesses. They need to learn to prioritize in all aspects: money, time, goals, happiness. And they need to be compatable. If you do all these things for each other, I think love, in most cases, will come.
Clearly we are dealing with one spouse that is UNWILLING to do anything or cooperate…. Also, Personally I feel that a person in such a marriage should be coaxed and encouraged to leave. Many times you find that the spouse is soo abused that they dont have the strength to demand a divorce when they really should. Nothing good can come out of such a marriage, not for the spouses and not for the kids..
Also, when either husband or wife wants to get a divorce and they are determined to do so, Is a rav able to say halacha recognized your reason as being invalid therefore, you cannot get divorced?