There are three ways you can upload documents in bulk, but none of them are called "bulk upload."
First, using the "Add Document" menu option within a project, you can upload multiple individual documents, each of which will have the same permissions, description, approval routing, etc.
Second, also via the "Add Document" option, you can upload a zip archive containing multiple files and even folders. There is an option in the Add Document window to extract the archive once it is uploaded, allowing you to create a potentially large number of documents by uploading a single file.
Third, using the DeskDocs utiility will allow you to drag-and-drop multiple files into your project space via a Windows Explorer window.