Multi-steps simulation (100 and more)

Hi!

Is there any way to optimize solver to solve hundreds of steps? I'm trying to simulate tunnel construction process and there is a lot of steps.
Right now with standard settings at the beginning simulation is quite fast but when it goes to next steps it's become very slow, even on very fast computer.
I tried to turn off DOF from previous steps but probably it's necessary for calculations.

Calculations are fast but 'initializing solver" can take hours...

Does anyone have advice? how to improve speed of computation? Please help!

Thanks in advance!