In Act 3, Scene 2 (Lines 132-137), what does Juliet plan to do with the cords. JULIET 132 Take up those cords: poor ropes, you are...

When she says these things, I do not believe that she is actually planning to do anything with the rope ladder.  I think she is just being dramatic.

The rope ladder was supposed to be used to let Romeo come up to her room so they could sleep together.  Now, she is saying, she is going to die and she will never sleep with any man.  At this point, there is no reason to think she is going to die.

I suppose you could say she is going to kill herself with the cords, but that doesn't make sense.  Just after she says the lines you cite, she gives the nurse a ring to bring to Romeo and tells the nurse to make sure Romeo comes to her room.  So she's not planning to kill herself.