Eliminating some expansion joints to improve seismic performance?

[brTCP]

I am retrofitting an existing building that is composed of highly irregular independent blocks. If I merge some blocks together (eliminating some of the joints), the structure becomes quite regular in plan. The joints are spaced at roughly 30m. The question is, what should I have in mind while analysing this possibility? The building is 20 years old, so I guess drying shrinkage is no longer an issue. There is temperature variation along the year, but this is something I think I can analyse and account for. What else should I consider?