If imported data uses a different coordinate system than your model uses, InfraWorks 360 will transform the imported data to the model's coordinate system during import. Specify a coordinate system for imported data or manually position imported data to resolve this.
Generally, InfraWorks 360 can correctly position imported data automatically, based on the data itself.
When you place a 3D model interactively, you can use the mouse wheel in conjunction with a modifier key to adjust it. This is useful for 3D models that have no world file.