What are "Solelos"?
Radak: They are wood [machines] to cast rocks 1 at walls of the city, to strike them (catapults).
Targum Yonasan: It is Malyasa. Radak - this is a big mound. They gather earth around the wall, in order to ascend from it onto the wall. This is like Chazal said (Mo'ed Katan 10b) Mulya b'Natza (bringing earth from a high place to a low place).
Above (6:6), Radak explained that Solelah is the rocks cast at the wall.
Why did he say that the city is given to the Bavliyim?
Malbim: There are three reasons why the city must be destroyed. (a) There are already Solelos (catapults or a mound - refer to 32:24:1:1-2) to conquer it. (b) The city is given to them due to the hunger, sword and plague. (c) You said that this would happen.
What is the meaning of "va'Asher Dibarta Hayah"?
Rashi: The evil that You said will come on it, it came.
