The　mechanical　characteristics　of　asymmetrical　multi-arch　tunnels　are　as　follows:　a　symmetric　geometry　and　structure　form,　large　excavation　span,　various　construction　processes　and　complex　structural　stress.　Therefore　in　the　design　of　supporting　structures,　the　load-structure　model　is　usually　used,　and　till　now　there　aren＇t　any　mature　methods　for　estimating　the　load.　In　this　context,　the　conditions　of　asymmetric　geometry　and　structure　form　of　two　cavities　of　a　tunnel　are　considered.　Based　on　the　assumption　of　the　double　collapsed　arches　of　multi-arch　tunnels　and　according　to　the　Protodyakonov＇s　theory,　a　formula　for　calculating　the　rock　pressure　under　deep　buried　conditions　is　derived.　Under　symmetrical　conditions,　the　derived　formula　becomes　the　conventional　formula　for　multi-arch　tunnels,　which　has　proved　the　validity　of　the　derived　formula.　The　research　methods　and　conclusions　may　provide　an　important　reference　for　the　determination　of　the　design　load　of　asymmetrical　multi-arch　tunnels.　©　2016,　Editorial　Office　of　Chinese　Journal　of　Geotechnical　Engineering.　All　right　reserved.