Abstract:

By using Mohr-Coulomb constitutive model, a three-dimensional numerical model was established for layered non-homogeneous subgrade of Suzhou Light Rail Transit Line 1; and the influential law of tunneling on neighboring loaded piles were also studied. Based on the numerical simulation results, with the increase of difference between soft and hard strata of layered non-homogeneous subgrade, the inflection point appeared at the loaded single pile due to tunneling; and the pile settlement also increased. The upper part of the loaded single pile in upper soft and lower hard strata had larger positive bending moment; while the larger negative bending moment happened at the lower part of the pile disposed in upper hard and lower soft strata. In contrast to the loaded single pile in homogeneous subgrade at the same position, there was larger axial force presented to pile top and pile tip of the loaded single pile in upper soft and lower hard strata; but the smaller axial force occurred at pile top of the loaded single pile in upper hard and lower soft strata. The horizontal displacement distribution of the front pile in loaded pile group which beared different concentrated loads coincided with the loaded single pile at the same position; while the deflection of the back pile was less than the loaded single pile. Besides, the influence caused by excavation of shield tunnel in layered non-homogeneous subgrade to the internal force of loaded pile group was more significant than the deformation.

Key words:

margin: 0cm 0cm 0pt, layout-grid-mode: both, layered non-homogeneous subgrade')">text-align: justify">layered non-homogeneous subgrade, shield tunnel, loaded piles, numerical analysis, deformation, internal force