A　time-dependent　unified　displacement　function　expressed　by　a　Fourier　series　is　used　as　the　displacement　boundary　condition　of　the　tunnel　cross-section　(BCTC).　Abel　element　expressed　by　the　fractional　differential　is　adopted　to　reflect　the　rheological　behaviours　of　the　surrounding　rock.　Using　Laplace　transform　and　the　inverse　transformation,　the　relaxation　modulus　of　the　Fractional　Generalized　Kelvin　constitutive　model　for　one-dimensional　(1D)　is　obtained.　The　effects　of　the　fractional　order　and　viscous　material　parameters　on　the　relaxation　modulus　are　analysed.　The　correspondence　principle　and　complex　variable　method　are　adopted　to　develop　the　elastic　analytical　solution　into　the　fractional　viscoelastic　analytical　solution　of　the　ground　displacement.　Two　factors　are　considered　to　capture　the　time　effect　of　ground　deformation:　a　time-dependent　displacement　BCTC　and　time-dependent　mechanical　parameters.　A　parameter　study　is　conducted　to　investigate　the　time　effect　of　the　ground　displacement.　The　deformation　parameters　of　the　tunnel　cross-section　are　first　calibrated　by　a　part　of　the　field　data　for　the　Longdong　tunnel　and　Gaoqiao　tunnel.　Based　on　the　calibrated　model,　the　proposed　method　can　well　predict　ground　displacement　due　to　the　time　effect.