Zurb Foundation has data-options="multi_expand: true" to allow multiple accordion sections to be expanded simultaneously, however as far as I can tell this option can only be specified in your HTML, so you cannot toggle this at runtime (i.e. to allow users to switch between modes without reloading the page).
I tried changing data-options="multi_expand: true" to false at runtime, after the page had loaded, and calling $(document).foundation(); (which is valid, according to the documentation, see "Adding New Content After Page Load"), however this did not have any effect and the accordion retains the multi_expand option value it had when the page was first loaded by the browser.