Historically, this was combated with counter tunneling. During a siege, a town would put plates or large glasses of water throughout the walls. If they started shaking, they would immediately try a counter tunnel, hoping to break through and kill the tunnelers, then collapse the tunnel. Though I don't know how effective it was. This was during the medieval period as well. So not sure if they did this in Roman times.

Be kinda funny to see plates of water sitting around all around the walls of a city