Analysis of influencing factors on settlement of widened subgrade based on differences in working conditions

The finite element method is used for numerical simulation analysis to explore the settlement characteristics of widened subgrade under the influence of different working conditions and factors. The research results show that at the end of the construction period, the maximum total settlement of the subgrade surface of the project of simultaneous widening and raising of the original subgrade is 1.97 cm, the maximum differential settlement of the subgrade surface is 0.21 cm, and the cross slope of the road arch increases by 1.4%. The maximum total settlement of the subgrade surface of the project of only widening of the original subgrade is 2.35 cm, which is an increase of 19.3% compared with the maximum total settlement of the subgrade surface of the project of simultaneous widening and raising of the original subgrade. The total settlement of the subgrade surface under the two working conditions varies with the change of filling materials and increases with the width, height, and slope ratio. When the width increases from 3.5 to 14 m, the maximum uncoordinated deformation of the subgrade surface of the project of simultaneous widening and raising of the original subgrade is increased from 0.54 to 1.31 cm, and the value of the subgrade surface settlement curvature of the splicing area for the project of only widening of the original subgrade is increased from 0.13 to 0.97. The obtained results can provide a reference for subgrade widening projects in the future.