The　tangential　interaction　at　the　ground-tunnel　interface　has　significant　effect　on　the　longitudinal　seismic　response　of　tunnels,　which　has　not　been　well　considered　in　previous　analytical　solutions　based　on　elastic　foundation　beam　models.　Firstly,　improved　elastic　foundation　beam　models　of　Timoshenko　beam　resting　on　Pasternak　or　Winkler　foundation　are　developed　for　circular　tunnels　under　longitudinally　propagating　shear　waves.　Wherein,　the　tangential　interaction　effect　is　taken　into　account　by　setting　independent　rotational　springs　on　the　Timoshenko　beam.　The　seismic　shear　waves　are　converted　into　free　filed　responses,　whose　displacement　and　two-times　shear　strain　are　applied　at　the　non-structural　side　of　the　Winkler　and　rotational　springs,　respectively.　Then,　based　on　the　improved　foundation　beam　models,　quasi-static　analytical　solutions　of　the　longitudinal　response　of　the　circular　tunnel　are　developed,　which　is　subjected　to　longitudinally　propagating　harmonic　shear　waves.　The　new　analytical　solutions　are　verified　by　comparing　with　the　three-dimensional　dynamic　numerical　results,　which　perform　far　better　than　those　based　on　traditional　foundation　beam　models.　Finally,　with　the　aid　of　proposed　analytical　solutions,　parametric　studies　are　conducted　to　investigate　the　effects　of　the　seismic　frequency,　the　ground　condition　and　the　lining　thickness　on　the　seismic-induced　bending　moment　and　shearing　force　of　the　tunnel　lining.　The　improved　foundation　beam　models　and　the　proposed　analytical　solutions　are　applicable　for　approximately　evaluating　the　longitudinal　response　of　circular　tunnels　in　seismic　area.